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Acta Neerlandica Botanica 347-379 (1960) 9 The Exobasidium Parasitism japonicum W. (Phytopathological of Shir. Azalea on Graafland “ Laboratory (received Willie Commelin Schölten ”, August 4th, Baarn) 1960) CONTENTS CHAPTER I. CHAPTER II. CHAPTER III. CHAPTER IV. TAXONOMY CHAPTER CHAPTER V. VI. VII. VIII. CHAPTER 347 AND OCCURRENCE THE CULTIVATION OF THE 4.1. Review Description MATERIAL of the USED 5.1. The plant 5.2. The isolation galls FOR X. 6.1. Literature . Experiments XI. Azalea 354 355 and 355 cultivation of Exobasidium japonicum OF 355 357 357 358 Exobasidium 359 species 7.1. Literature 7.2. Experiments 360 INOCULATIONS 363 CROSS 359 Cross inoculations with from different Cross inoculations DEVELOPMENTAL with CHAPTER 353 EXPERIMENTS on THE Azalea on material 6.2. CYCLE 352 fungus EXPERIMENTS INOCULATION LIFE the of Azalea STAGES OF THE spores originating spores originating 363 Exobasidium closely related OF Exobasidium japonicum CONTROL Exobasidium cultivars with from different less CHAPTER 351 DISEASE of literature Anatomy THE 8.2. IX. 349 AZALEAS 352 4.2. 8.1. CHAPTER OF FUNGUS 4.3. CHAPTER page INTRODUCTION THE is BUD AT host 369 Control by 10.3. Experiments with fungicides in vitro 10.4. Experiments with in Ustilago, . 366 10.2. dium, . possible Hygienic OF 364 . INFECTION DISEASE 10.1. DISCUSSION plants WHICH 369 measures THE fungicides 369 . fungicides RELATIONS Tilletia . AND BETWEEN 370 vivo THE 371 GENERA Exobasi- 374 Taphrina SUMMARY . 376 378 REFERENCES CHAPTER I INTRODUCTION The growing cultural Ghent centres in of of Belgium, Azaleas Western and s an Europe, Boskoop in 347 important part in many hortisuch the as Dresden in Netherlands. Germany, Every year 348 W. Dutch growers plants, from the plants sold. are The which, ziekte” like shaped ears. be recognized, (Plate be disease is The Shir, and the cells, the basidia form the cells, they basidia. numbers, to who disease of this of spaces century. Japan, for Shirai (1896). The Thus, After first and galls they give lacking: a cient to cubation is an question period infection, be to varies preventive measures out with applied before and after This kind of scale be in the research, a is it small how the This at the turn plants from that country by known. paper, of the para- questions still was does the parasite basidiospore suffi- heterothallic? the conditions. length of the The presence inof but the moment of infection is difficult for the growers observed, have of with nature one fungus was different is over, owner Europe following the answered under easily can is frequently described in this circumstances; or are healthy plant. a stage of the development of the plant produce carried the that stage. only incompletely concerning to The at of the described experiments answer yet unknown. Therefore, when were An fungus. symptoms as purpose they as a produced are flowering period imported Azalea is on of epidermal the reddish to surprise was already of the and under which Another the possible the consists velvety appearance. time in Western that it japonicum produces and the latter as possession of the first was the to himself in fungus at what penetrate hypertrophic tissue, through becomes white obtain better information sitism of this these epidermis, breaking the lifecycle of Exobasidium the to was the because no mycelium of the fungus leaf the under the suddenly, appear thought It is can Exobasidium as The basidiospores, observed for was are longer misshapes reminded article galls develop gradually, often unobserved, Azalea, leaves and crooked of the leaves hidden under flowers and leaves. When the seem “oortjes as deformed convex fungus known a colour of the diseased parts The Rhododendron group. greatly enlarged and thicker are Basidiomycetes. develops of enormous by the to layer in the In this B). be to names galls. intercellular which hymenium, the to that becoming and A caused belonging in present 1, called ready are grown young under the disease known in Dutch original shape The mostly nurseries these of cultivars great variety a and it is understandable that these ears will organs belong a indicating the leafblades normal, irregular growth. people of suffer from and flower, to The diseased leaves of Azaleas, In the Dutch consists of all speaking, plants buying of Azaleas that is obtusa, “ezelsoren”, or begin they assortment botanically Often these for sums horticulturists. until grown large large Belgian indica and Azalea Azalea than spend GRAAFLAND to be carried number the Azaleas were of out. Some fungicides, which inoculated with the however, will have to be to know experiments continued were parasite. in large- cultures. In this paper the Azalea some parasite. Exobasidium on attention is Shirai also (1896) the ‘Indian Azalea’. has paid to the nomenclature of been the first American to describe mycologists an described THE parasites Ericaceae PARASITISM OF EXOBASIDIUM wild Rhododendron on family still genus Exobasidium. It is distinct, are described be to by Woronin that distinction host of different their host on their has of plants. parasites should species authors Many as the prove of are morphological no living to the answer on different question whether they show specialization whether or collection of host a The however, restricted paper were, and vaccinii named and parasites to us To that purpose indispensable. is the Shirai by inoculations with Exobasidium spores cross fully identical, are priority. between found species of the new described conspecific, are origin would enable parasites as question whether all these species 1867. If the various actually 349 AZALEA other members of the on America parasites name The results plants. these be can in this they open ON identical with Exobasidium are conspecific, opinion the whether or American authors an and species in North occurring SHIR. JAPONICUM plants with described in experiments this inoculations with Exobasidium cross originating from Azalea and from Vaccinium vitis idaea. This Vaccinium and Azalea cultivars some The purpose aforesaid used were investigation and whether investigate to that described by Woronin. Finally, the of Exobasidium spp. parasitism belonging the to Ascomycetes, TAXONOMY AND Linnaeus described in his the which he plants. obtain will About an to answer described in 1851. later More well as fungus is identical with similarity between striking be by Taphrina II OF AZALEAS Species Plantarum (1753) ferrugineum. the red This, Alpine therefore, Hooker’s as species expedition species new to Western to hardy The latter between retain The more Azalea latter Anthodendron. bearing subgenus species, is which shed placed were and Indo- China, Japan, Burma, as can a leathery divided the in All However, leaves which arc practice placed are experiments were not shed about called performed 900 non- as justified to Eurhododendron and will As the In the soft-leaved name Azalea be used in this with Rhododendron to species winter. non-hardy, Azalea. type. The Japanese Azaleas may be assigned hybridization not Rhododendron during 70 name is sunk into Rhododendron. the assigned are it easy, subgenera; two are generally used by the growers, the too. is species into former Anthodendron which hardy to under unfavourable conditions. distinct genus. It should be be To their leaves in the genus Azalea. less were Europe called Rhododendron and ones, known, including hardy ones, is Himalayas Europe, which introduced into were from Western the China, Malaya and other Asiatic countries. At present about 800 are spp., discussed. CULTIVATION Rhododendron new from America species the Rhododendron. genus century a 45 this and that shown named Rhododendron of the type brought to the CHAPTER Rose, host as was questions concerning the life cycle of the Exobasidium parasite Azalea, on of this paper plants of this the ‘Tsutsutsi’ section 350 GRAAFLAND W. of the subgenus Anthodendron. They Rhododendron obtusum Planch, Rhododendron other kaempferi, Japanese species. small- and Other cultivars ‘Galestin’ and group, originating from The W. grower cultivar pink-flowered indica. A obtusum var. nurseries For the cultivation woods of the The plants old, the the age is the cultivar amoenum “Campine”, a “baby Azaleas” of trimming the plants can either beds has rooting to be value into be of the Dutch the indica Netherlands guilders in indica and Azalea obtusa plants the to plants greenhouse. under exposure be kept in the brought time of the ture In all are too high, greenhouses cases of the soil 16° a are the time the are at during the or which plants start and 1.2 million according Guide), to the 540.000 Azalea conditions. climatological greenhouses till the they have and winter they to their beginning (Van Raalte, open autumn The Luxembourg about at have flowering, firms. Belgian year, 1955). They be returned exposed are C, which may be raised gradually may opened in occur order in at plants are a blowing means to the doors temperature. high moisture of mist content the sprayers, plants during as well as during the time they are spraying and the opening of the glass- outside This through the spread easily from diseased the spores are glasshouses. organisms, including spores of pathogens such dity of the air keeps the good development. Therefore, sprayed, often by the early spring, lower to house doors in order to lower the temperature be at by the Dutch auctions. high humidity of the air and kept in the glasshouses. can and obtained night frosts is still necessary. autumn which conditions for continuously air-currents months development of the flower buds. However, if the tempera- becomes the During fir Belgium. night frost by shedding into the late and leaves, are they from that our to an against of about i.e. before estimated In of humidity of the air in the plants, sold were 8 to cuttings Horticultural (Dutch to are protection temperature of was Belgian When 8 September, to growers densely planted in the beds. In are a they have May, when they However, on of 6 The year 1960). in the oak cuttings. imports from Belgium hardy not are Most varieties react leaves. Thus Young 1957 grown used from The second a (Vandendael, “Tuinbouwgids”, The August April. Dutch bought by Azalea 1960 of high. kept in the nursery for frequently are to in and period between February by 1959). from sold. called Rhododendron a in the northern part or be The Indian and is species and are ‘Kurume’ the Azalea obtusa. possession in are they 18 months seed seed. Japanese to frequently is soil region grown from are ‘Hexe’ with plains, obtained the horticulture of ancestor, 1954; Encke, of Azaleas from belong as as of this hybrid (Grootendorst, Japanese centre growers Azalea has Rhododendron simsii Planch, the growers Azalea crossing of the hardy a Koppcschaar They all designated by the are F. Boskoop the at grown by the ‘Esmeralda’ ‘Moederkensdag’. and also called ‘Kurume’ Azaleas. are obtained was to as the In and favours The of way Exobasidium healthy plants. viable cause this heavy micro- japonicum, high humi- infection. THE PARASITISM OF EXOBASIDIUM JAPONICUM CHAPTER In the of centra tible the varieties, such plant same somewhat covered An to seem the among period is the finished, but this may be the their resuming plants whithering plants have been moved clear from may these facts the as appear as to well buds the start as By hypertrophic growth they into turn colour and a the lating, and the colour clusters The may of the spores, blastospores diseased tissues come as of these name brown and attack all well caused which usually sharply will fall parts, parasite. from separated still in a the observation leaves. The dormant of of the more always as the galls gets green to will plant except a light starts covered the a activity appearance of the was state. assumed that This galls appear in after, galls shrivel, The occur on be- parasite hypertrophic The with leaves growth the hypertrophic leaves, part is healthy leaf tissue. pathogen. galls here velvety aspect. are a bud can never present simultaneously a on with developing This would also plants be infected hypothesis is in agreement with fully developed the which were expanding bud. The growth by the dormant bud would coincide with of the account from the basidio- expounded however, attacked. are powdery aspect, becomes show green sporu- root tissue. Stems and may galls, young conspicuous. snow-white. On be galls basidiospores a sprouting disintegrate: therefore, that young galls and spores rapidly the to after become the on spots shape, and with of the young but still folded leaves of tion galls young used; this gives them Most begin weeks all sorts of saprophytes. prey to From these observations it when The subsequently only partially are plants flowering, buds some become soon of the which, be of the parts the by galls for then soon flower as after observations that own cuticle, changes from light the surface spores, the the rupture development of secondary of the our irregular that time the surface some- time the axillary translucent swollen, an and 1952). One gets smooth, shining surface. When the fungus basidia formed. At of galls galls flowering greenhouses. open, occurs occurs unfold. to leaves. They somewhat the certain outside, i.e. in June. It has become from as the the at This flowers visible small, appear growth also vegetative in kept (Welvaert, too galls this time the at plants in the on in revealed that growers vegetative development. Renewed develop. of the that extent an optimum an still are September most underneath the when the in so that impression are has Belgian During June galls may be frequent to such are the many big galls Though the galls appear spores. formation gall year, of disease, frequently. Suscep- latter The ones. Exobasidium its normal red flowers also frequent during March and April; most times the occurs besides carry 351 AZALEA DISEASE cultivation century still amounts enormous inquiry a THE ‘Hexe’, may be diseased as may the throughout are Azalea half deformed white with months. the over ON III OCCURRENCE OF already known for SHIR. explain a resumprenewal the sudden apparently healthy 352 W. when imported. with that GRAAFLAND This mode of be development would in agreement ' camelliae described gracilis var. Wolf by Shirai and Wolf THE Review The he of Exobasidium IV FUNGUS literature genus Exobasidium described for Camellia sasanqua. on CHAPTER 4.1. (1952) the fungus Exobasidium vaccinii. by Woronin (1867), proposed was causing disease a in Though Fugkel (1861) Vaccinium vitis had observed when idaea the as fungus already at an earlier date, this author did not give a good description pathogen, which he mistook for a Fusidium. After the appearance of the of Woronin’s scribed. publication, Usually they other many Exobasidium the named after were species host they occurred, but knowledge of their pathogenicity first Exobasidium occurring was described on a North American wild have by In country. Both this authors 14-15 /i. a In Belgian a Laubert the disease Japan, validity a of many of on could prove several siders parasite the was Exobasidium hosts, between these ces names that of the of the last often both parasites Andromeda on to prove Exobasidium as be discoideum species first one Ellis and could be be found. species be impossible to of latter. cause similar respect (1877) azaleae con- Peck as morphological differen- According are the to this author superfluous, and only retained. Naumann (1909) was cautious in his identity of the Exobasidia occurring in to no the account identical with to Farlow Exobasidium as about on morphological indistinguishable. mentioned should In Exobasidium as was Germany Ragiborski after able by im- Exobasidium doubt called 1900. been In 1909). in were ligus trina. with created species and had flavum already attack in mentioned Shir. (Naumann, as parasite an report fi. Shirai Japan nursery was either Rhododendron in same 15-20 of this probably pentasporium 1906 on to indica which idcntical with Exobasidium vaccinii Won, the first Dutch a identical (1896) different the that Exobasidium andromedae Peck symptoms species in the is indica basidiospores in in growing Azalea Azalea Exobasidium Exobasidium vaccinii Won, disease of be would Richards Ellis. their presence attack discovered was was observed Exobasidium, with determined (1909) discoideum He This or (1901) It occurred basidiospores shape of the galls. on of the length Bos an nursery Shir, occurring Peck azaleae (1909). from ported japonicum The Its basidiospores the to The genus Rhododendron (1874) described Exo- nudiflora of the which on lacking. was discoideum. Peck year Azalea length parasite Ritzema Exobasidium by same much attention paid Exobasidium japonicum. was Exobasidium as wild the species described (1896) the the the species, viz. Azalea viscosa. In fi. from of species a (1874) Ellis length of 20 a basidium azaleae on de- were plants identify the parasites conclusion Germany. on concerning He the considers the base of their it morpho- THE logy PARASITISM alone. Many differences and Wor. belonging species to (1929) on 1925; occurring Exobasidium author, latter Exobasidium azaleae the Laubert ( 1909 and Exobasidium name clear. This also according to this ~ good species. Exobasidium the to that on of of them them different host question whether inoculations Azalea and 4.2. Description depends a on Fig. 1. of in Europe, may be Basidia Cramer, regarded exists were is of seems is It a the is not parasite However, or ~ the fungus intercellular. on been not forms a occurs another ~**.*^».**~* of many described as new excluded, however, speciales occurring can give an not. In this the to answer investigation originating idaea. azalea The width of the spaces. The developing basidiospores (bs) basidiospores ~ parasites belonging performed with Exobasidium spp. vitis be morphology formae as to ~ layer. The apices of the hyphae, (b) that by Woronin hirsutum. several erroneously identical. from Vaccinium this and Azalea on remarks 7 the studied opinion that have are 1 who galls to Ellis parasite he that described the width of the intercellular subepidermal the Rhododendron not specialization cross mycelium for plants. Only experiments from The (1959), is also Exobasidium Several some Japan but Savxle species, genus species. of cause According discoideum though X. < 1915; Marghionatto author, Exobasidium pentasporium Shir., which in as Exobasidium identical with Exobasidium vaccinii Shir., and all the Exobasidium rhododendri jerrugineum indica Azalea on to Wor. Argentina. retains and species applies Rhododendron on are 1932) described were 1959). Exobasidium Peck, japonicum difference between this in vaccinii 1913; Burt, (Lind, the that be considered to comprise Savile, vaccinii cultivated Exobasidium rhododendri Cramer Wor. species and 1928; Farlow that species would 353 AZALEA of Exobasidium parasites have Rhododendron Azaleas on Exobasidium the Miles, considers too the species; one occurring Laubert, of ON with agree basidiospores small that these so SHIR. JAPONICUM however, between the of several are EXOBASIDIUM authors, in size afterwards OF blastospore on hyphae, the future sterigmata (s). (bl) in ± 1 n, mycelium forms situ. basidia. One of the 354 GRAAFLAND W. stretch in direction a perpendicular the to thus epidermis, the hymenium. By further growth the basidia find their the epidermal cells and rupture the cuticle. 24-30 cal, 5 on one (Fig. 5-8 X [x. basidium. to Mix products, which reminds Among In this be case called 4.3. but Fig. is of seen paper the between the basi- produce may for these “blastospores” outgrowths formed by yeast cells. many forms produce are occur, new called e.g. spores “sporidia” the smut by budding. “second- or spores of Exobasidium will yeast-like the galls between on azalea (p. 351), but also microscopically the transverse found in Transverse section palissade parenchyma (p) the sections. There is part, uniform through and a sharp healthy and the diseased tissue, when mesophyll of the hypertrophic sparingly 2. this “conidia” Taphrina and far that both name to number of as exists analogy an 4 2.5-5.5 [i X large a designated genus so 13-18 “blastospores”. gall is studied in in the too basidiospores only macroscopically boundary of the one newly formed spores In Anatomy Not a the sporidia”. the in the uses Protobasidiomycetes in which fungi, ary the of the is cylindri- are sterigmata, on produce are (1949), Exobasidium, by budding. spores Mix ascospores of the genus diospores basidiospores They /x. The basidia develop basidiospores 2-4 X According the behaviour of the new the measuring 9-13 Woronin. basidiospores The size of the budding 1). By spores, by The forming between way an spongy a lack of differentiation and tracheal elements tissue. In comparison infected leaf, showing parenchyma (s), hypertrophic cells (h). and a a healthy with are the part with diseased part with W. GRAAFLAND: The parasitism of Exobasidium japonicum Shir, on Azalea PLATE B A U C E F Plate 1. Shir. B. A. Azalea oblusa, Azalea indica, G cultivar ‘Esmeralda’, with C-G. Development of’ axillary tation of the D-G; further shoot. C: ‘Hexe’, cultivar just developmental in with galls galls japonicum Shir. buds of Azalea indica, cultivar ‘Hexe’, after decapi- after decapitation; length of the buds about 2 of the buds in D: 4 E: 6.5 mm; in stages; length F; of Exobasidium japonicum of Exobasidium 9 mm and in G: 12 mm. mm. mm; THE normal both The epidermal is layer white the on Azaleas ‘Esmeralda’, and flowers red in frequently ‘Hexe’ the gathered in The Azaleas those observed to V THE still growing double mold, in the in grown growth vitis and nature length glasshouse, The flowering, and of use The for idaea, in to the stable the shoots were cut manure buds. Small suitable for they cuttings soil was 1/3 April, while the plants cut in composed of sand. July Roots The were as isolation early been added. the the obtained with 3 formation culture by sprouting. grow the were was obtained humidity high. some soil mixture weeks the after tips of unfolding of the axillary to 4 branches which as and the cultivation germination of 1867. Under humid of were in a liquid Richards fungus medium, conditions (1896), in pure in which had failed. of Exobasidium they sprouted grew the the however, reported culture, japonicum [Exobasidium basidiospores yeast-like way, forming “conidia”. Brefeld (1889) in pure 1/3 leaf in 4-6 weeks. root same After in the of under experiments. Woronin observed vaccinii had in potted were while August, mixture a developed stimulate to or kept in the glasshouse were removed, resulting plants the disease. inoculation tests cross garden of the laboratory. either in were growth substance cuttings were grown characteristic, the Exobasidium in use clay seedpans and by keeping rooted pink, Because variety is favourable conditions for rooting necessary. Very by the were with (Belgium). this An unfavourable grown or and moss treatment with cultivars ‘Moederkensdag’, multiplied by cuttings. Young, recently hardened cm glass-cover. 1/3 peat three Boskoop and nurseries. of doors. The out EXPERIMENTS obtained from Ghent Belgian were shoots of about 8 to similar are respectively. was of Vaccinium Specimens a healthy appearance differentiation of the tissues stems, however, is the susceptibility of this variety 5.2. their though the basidia. by ‘Galestin’ vegetative of its excellent some 1929 and material Japanese The cultivar not have by several other enlarged, their They keep burst The anatomical features plant used, viz. A size 2). Marchionatto, not are MATERIAL USED FOR The Of the were their (Fig. leaf. THE were 355 AZALEA as occur observed been CHAPTER 5.1. ON well as 1909; however, increased. abnormally lacking. in the has Naumann, galls which develop also cells hypertrophy picture cells, epidermal the In is of and SHIR. JAPONICUM 1932). number is until 1907; (Petri, Laubert, number hyperplasy anatomical same authors EXOBASIDIUM OF the mesophyll, increased: This PARASITISM cells in fungus multiplied that his attempts Lockhart (1958) 356 obtained of a pure culture of this Exobasidium basidiospores on Marghionatto basidium Graafland Exobasidium rhododendri hirsutum ; be culture. pure to the report The growth of Exo- “conidia” grew Exobasidium developed on japonicum from Rhododenfrom vexans Thea sinensis succeeded in vaccinii Wor. from Exobasidium from from Vaccinium Rhododendron Shir, japonicum vitis idaea: Exobasidium and Rhododendron ferrugineum from Azalea Exobasidium indica; Thea sinensis. following method the growing 4 species of Exobasidium viz.: Cramer Massee The the first was (1955) (1953) culture, pure vexans in kaempferi and Exobasidium var. suspension out a culture. pure in (1929) Ezuka dron obtusum by pouring agar. japonicum potato-agar. in GRAAFLAND W. to grow the suitable fungus in pure culture appeared Young, newly sporulating galls were gathered from the host plants. They were placed in sterile petri dishes, to where most humidity wool. The leaves by one: kept high by the presence of was well galls keep used, the galls are wrapping the in this be can surface cut way. kept fresh for of the shoot in sporulating surfaces of the galls have towards the bottom of the expelled Even nating. they be can taken 6 After agar. formed with which and is within 24 so a many small, possible allow the forcibly they start germi- blastospores needle and typical of Exobasidium colonies, Malt surface The growth. wrinkled like and becomes and fungi malt-saleb It is and possible is to i.e. of the with colonies of a favourable most are of every grow two sunken a mycelial the surface temperature in beyond the solution. cells of irregular brain. On yellow the to shape. 13 to 30 hyphae is 1-2 fi, /u. form, in which galls crooked in old of the with in A a growth of optimal. is The japonicum, Exobasidium vaccinii on agar. development of the fungus does fungal finely malt most brown. mycelial particles divided solution is mat. With suspension most good throughout sprout consisting favourable for of ob- culture. a Microscopically from the the centre gradually mat for 20-22° C the formation of the culture This results such taining shake a are months. Exobasidium otherwise necessary, proceed that nutrient a Exobasidium rhododendri in nutrient solutions instead of aeration the A subcultured also Shaking not agar cultures. were to glassy of the nutrient media used the colour darkens from Exobasidium formed are transferred hemi-spherical, The as much as to longer time even cotton wool. where glass, cotton hypertrophic shiny surface. Gradually they develop the appearance a peripheral shrivels days 8 to hours off with the on an be turned to plug of wet with wet petri dish, in order fall to basidiospores a If shoots a cultures, the length depending Their case knob are The on threads hyphae grown on agar varies the nutrients used. The width of the shape is irregular, but part of them they plants. of the on one are similar to particles or both formed, the may ends. blastospores also be are fusi- formed rectangular Sometimes, though the latter can on or especially never be THE considered each to PARASITISM be to real (Fig. other OF EXOBASIDIUM hyphae, threads to the typical 3. the cells found. ever are ON 357 AZALEA only loosely attached are shaped. uniform; cells cohering (bs), formed are the on their length is forming hyphae and Especially Germinating basidiospore more Though the cells Exobasidium-blastospores irregularly more Fig. hardly are the cells as SHIR. 3). In the nutrient solutions in JAPONICUM CHAPTER comparable galls, they are variable. more blastospores (bl). VI INOCULATION EXPERIMENTS 6.1. Literature Inoculations galls in with infecting already healthy plants result Lockhart with (1958) leaves of shoots angustifolium, basidiospores information is with developing three months basidiospores. out observed Graafland (1953) of Exobasidium available with basidiospores disease these regard from (1896) and on and of basi- obtained Gaylussaccia myrtilloides plants succeeded means symptoms inoculated vexans, taken and ligustrina Vaccinium after by Richards ones. typical on idaea sporulating who (1867), of Vaccinium vitis Andromeda from directly by Woronin diospores obtained from diseased similar taken basidiospores performed were the on a resinosa. young Vaccinium had been treated with young obtained tea good plants results. with No to inoculations of Azalea carried the galls. 358 W. Inoculations with that the spores those Vaccinium Similar results of the spores obtained 6.2. the and As by para- after inocuwith angustifolium blasto- difference between the results no of means buds the galls basidiospores originating grown in pure culture. the two ends were removed. As, After expand. to buds had not the terminal than bud inoculating broken. than 4 more axillary 4 point surrounded by only The bud-scales. different were present, of means small buds covered and glass with the filter after about 3 much at when the period the was weeks, at When sometimes plants diminutive covered by It not diseased Then paper. the if the nights could much be longer leaves, achieve plants low 4 inoculate are were had in if by to were opened, visible were not i.e. C, for 24 inside symptoms cool, ones kept the on these blastospores, were 0°-5° difficult growing a of which chambers as fallen too September the incubation weeks. than 3 than decapitated of healthy to temperatures were 10 of these leaves also which been stems began decapitated, more to easy and The first had as was about the be to galls obtained after inoculation were however, to shoot per consists plants inoculated removed. least performed was without much this larger treatment. 1). (Table Table Number is Basidiospores The filter temperature was latter inoculation-chambers, paper The number of when brush. moist night. 6 from the are uppermost buds 5 this although stages. organs. transferred moist a hours in to be order In small too were The one. terminal bud is developmental tightly packed plants inoculated, was an to for leaves inoculation, the expand after the removal of the tip, only the treated with inoculum. If the the inoculated, and the tips of the were usually, be to used were when clear that inoculation had axillary buds these cuttings visible already are was began of dormancy growing vigorously the length it in mm before 30 on results Experiments few in and effects good by Lockhart (1958) was by culture culture of the pure and those obtained with cells plants inoculations. to a were clearly, very similar have Vaccinium fungus. There inoculations Well-rooted a and not obtained (1953) obtained were myrtilloides same with from the Graafland culture pure obtained in pure plant with cells taken from Vaccinium lating vaccinii in though states, basidiospores sprouting idaea. this inoculating site. by vitis He (1889). of Exobasidium formed obtained blastospores Brefeld performed by GRAAFLAND of galls on groups tation, of and 5 plants 1 inoculated with basidiospores after inoculated without number Azalea cultivars shoots decapitated ‘Esmeralda’ ‘Galestin’ decapi- decapitation. of galls shoots not decapitated 4 0 14 3 THE PARASITISM Thus the able for EXOBASIDIUM development of the symptoms. lation was could successfully greatly simplified when it suspensions from the was shaking the be inoculum a shake culture. suspended the cultivars gall, plants sink to it brushing the number of a ON the ‘Esmeralda’ 14 of the were flask. After used was the For plants. and ‘Galestin’ with days old, give the cell to bottom of the inoculated with were favour- of inocu- especially was night in order the buds be to technique cultures, pure one to 359 AZALEA fluid, the viscose suspension on and the others The When the culture during oppertunity by experiment SHIR. discovered that inoculations was with performed discarding the supernatant from JAPONICUM development of the axillary buds appeared the material OF used. were as first Half basidiospores originating treated with suspension of the pure a culture. number of The with which galls developed the on larger than the number that developed even basidiospores (Table galls of that developed basidiospores and with group was treated plants 2). 2 Table Number latter the on on of 5 groups suspensions of treated respectively with plants cells in grown a culture. pure inoculated with Azalea cultivars basidiospores cell suspension a ‘Esmeralda’ 4 5 ‘Galestin’ 7 9 After such favourable all further experiments results had were been obtained with suspensions, performed with material grown in shake cultures. Cultures in of Exobasidium and Exobasidium japonicum 1952 have remained virulent up to now, vaccinii isolated inoculation host become infected. plants CHAPTER THE 7.1. after as LIFE CYCLE OF VII EXOBASIDIUM SPECIES Literature The mode of infection brilliant minate on “conidia” formed the leaves developed into myrtilloides to and In a vitis penetrated intercellular systemic, attention idaea. Vaccinium occurs and revealed Sometimes via the the has been (1956) angustifolium, stomata the spaces network within 48 hours after Hilborn & Hyland of was by the basidiospores proved to ger- secundary by budding, but usually the spores themselves the by Exobasidium vaccinii becomes Vaccinium which tubes, cells. According of formed were germ epidermal Much of Exobasidium vaccinii observations of Woronin. The the the way the hyphae the infection. “lowbush stem. mycelium is perennial to via the infection of Vaccinium via the cuticle of the paid or branching blueberry”, The infection in the rhizomes. in which the tea plant 360 becomes infected & GRAAFLAND W. 1950; Loos, by Exobasidium 1949 and 1948, Loos, This 1951). leaf reckoned from the 1950; parasite tube. From the do parasite cell epidermal outer form not and Marghionatto leaves the on species extensively. basidia of of Paris. sidium discoideum these in the it nuclei After one. of 4 the was not this grown Shir. Exoba- from their According to Also dicaryotic. are rise vicinity be to monocaryotic, are fuse which present, gives the latter and the the especially fungus are in fungus mycelium distinct nuclei divisions known in what stage of which condition of the the first of all fusion outside the host basidiospores, a appeared fusion the 4 to several poles, which side, resulting each bearing each a to a haploid the ring, on by nor glass slide a 4 also the cell a the a to of the possibility chamber moist a allowed out The 5). in glued was were haematoxylin. developed and studied was with question possibility of stained with (Fig. the latter this and investigated. For that purpose were gall diploidi- dicaryotic the answer the blastospores spores in the bottom of the sporulating directed side had been drop of malt agar % agar). By keeping the moist chamber upside we basidiospores collected germinated, which could be observed obtained that the spore contents germination terminal neither other, be of the of spores the spores in the formation either of 2 became divided observed: as mature on every The microscopically. after 1 hours, Nearly a glass slip; placed (5 % malt in the agar. these the cover to gall caught uninucleate piece of inside towards the down for be had the cycle basidiospores, Secondly, the nuclei well as to between culture. A small chamber of the life recognizable whether the plant a mature germinate, after which The is uninucleate. are basidiospores from former, result mycelium found in the leaves. To had to know blastospores really on Azaleas basidiospores. yet zation occurs, of young Experiments It to are (1925) the mycelium, the japonicum of basidiospores two germ of Exobasidium cytology concluded, of the intercellular the cells a penetrate may Marghal to considered this be can the spores, on Exobasidium young basidia two diploid we occurring was the authors, whereas it According studied authors Ellis, that illustrations, 7.2. these develop the way in which Azaleas studied the They Though they hypha a the buds. (1927) Exobasidium an the 4th or the germ tubes penetrate into (1929) Kharbush & but cuticle to japonicum. during the unfolding of Eftimiu the 3rd even wall. Exobasidium by 1949 and Emden, developing bud. The basidiospores a Only little is known with regard infected 1947; Gadd (Tubbs, van attack can blastospores, appressorium an & tip of the stem, i.e. the leaf which is just fully developed, and also the leaves of of this Massee vexans Reitsma blastospore. one or were more took towards place blastospores or on of 2 the 2 either hyphae In the meantime the spore itself septae. basidiospores moved No lying blastospores originating sign of cell fusion in the from was ever neighbourhood of different basidiospores THE Fig. 4. PARASITISM Basidiospores OF EXOBASIDIUM with nuclei JAPONICUM stained SHIR. ON 361 AZALEA with haematoxylin. Fig. Fig. Fig. 5. 6. Blastospores a\ developed a shake Two germinating basidiospores dium, forming hyphae of in hyphae of a, and after 5, blastospores 10, 29 and culture, stained with haematoxylin. (bsj and bs 2 ) originated from (bl). b, 45 c, d and e: Blastospores hours, respectively. 5 one basi- and tips 362 W. ever conjugating seen other by only though they even small a GRAAFLAND distance. against each other without making chamber cultures probably it existed, basidiospores from fusion no the found in were basidium. same 6). In of 4 groups If + attention observed. was spores behave in similar a It paid was and be may concluded or 5, spores — these cases, to grew many moist might be expected that both would be represented Therefore, special groups. here the originating blastospores of (Fig. contact from each separated were colonies The in these but that in even vitro all way. Another possibility that had to be investigated, is that the dicaryotic mycelium in the young leaves develops after a union of the spores of the or tration. tubes either germ If the fungus be spore would were homothallic, ment of of cultures contained only sticking the to ascertained on by 10 of these cultures colony caused concluded galls that derived from and the pene- one the case — fungus developdispose to necessary plants 3 the to group of fungus is a ability of 5 group are able agar. In 2 tested Five of them monospore Thus it plants. one this way was plants, 5 was After infection. because cul- may be cells sporidial develop into to needle spore one cause and 3 plants of 5 one colony. a all on shake a a the malt agar After it had been Each to homothallic, single blastospore a its on on malt to infection cause into obtained. were out on taken only that develop of suspension drop placed was transferred as 4 of the on a a examination was to that drop a cultures test proved caused infection tures was moist chamber culture. a allowed to was monospore far so Such slip of microscopic the latter 5 group of a obtained from were cell. one cover weeks the two infection. In would be necessary for spore the latter by diluting present, one an after or + one cultures. Monospore about only accomplish to of the leaves at least heterothallic, gall. To investigate this question it a monospore culture to required the surface on were dicaryotic a mycelium. Monobasidiospore tures had to be of to one cultures described before as obtained in The time kept upside down, however, minutes two diospores were (p. 360). appeared from separated each to other colonies into which they developed did microscopically. more cover the slip, basidiospore to isolate from was the in which 21 basidia. In two than suitable such 34 a basidiospores group In were originated instances it was and 5 probably tested colonies were derived separately on from obtained the Azalea it to grow a from same 5 colony These on only the one colonies obtained, to different out same the possible was were basidiospores basidium. that separate cultures period controlled present basidiospores belonging possible A obtain basi- was cases raise to basidiospores which probably originated from the Once, to cultures many monobasidiospore from short. distance a in others 2 to 5. In three of such all 10 by but now most cul- chamber which the chamber not touch. This discarded. was present, spores them. All among of 4 If culture was be moist during of each basidium. which cultures were were plants. They all caused infection (Table 3). THE PARASITISM OF EXOBASIDIUM JAPONICUM Table Number of plants number of each one developing galls after monospore cultures; used inoculate was to SHIR. ON 363 AZALEA 3 inoculationwith cultures monobasidiospore numerator: number of plants with galls denominator; plants 5 number of 9 45/9 X 5 6 24/6 x 5 6 18/6 x 5 10/2 X 5 4/1 x 5 3/1 x 5 2 ) 1 / originating ) one the 1 1 ) 3 S 2 } 1 basidiospores basidium 5/1 x 5 12/3 x 5 10/2 X 5 4/1 x 5 6/2 X 5 same the > from same 2 These experiments Monocaryotic cells, and, diospore wall of the that Exobasidium prove formed therefore, be no by a process genotypically is formed in difference CROSS Cross from azalea The Exobasidium varieties which very galls grown have in are group caused by Morphologically to galls be on identical, culations were suspensions from infected tin’, by only might performed shake shows that the on the be infected ‘Hexe’ It as could cultivars, 13-18 occur. with with the caused be found and the fungus latter Ghent, to seem on a the be these different like the Belgian Japanese versa. from on as well shape proved physioloino- cross as the other with cell originating ‘Esmeralda’ and ‘Galescultivar ‘Hexe’. Japanese ‘Esmeralda’. plants question, Azalea could The the too However, (i. this study one between basidiospores 2.5-5.5 X To of the infections grown in uncertain whether yet basidiospores cultures, from The ancestor. is Azalea obtusum Japanese parasite, causing galls in all cultivars. Belgian cultivar and vice easily originating parasites, each occurring one plants parasite spores the cultivars on plants of the Japanese cultivars and from infected the dica- of cells between which there the on as as differences measuring from well simsii the different specialization gical as two different no the leaf tissue outer VIII found are the disease. or In basi- one the penetrate Exobasidium with Boskoop to of cultivars of the galls out of cultivars Rhododendron susceptible identical, out INOCULATIONS inoculations different japonicum is homothallic. budding sex. CHAPTER 8.1. of of the young leaves. epidermis ryotic mycelium, therefore, can inoculated plants of the Table 4 galls cause cultivars could parasite from The same cultivar, but 364 W. GRAAFLAND Table Number of galls developing of Exobasidium 4 different number of origin Azalea after inoculation of number galls number of plants *) ‘Hexe’ 16/6 ‘Galestin’ ‘Hexe’ 25/6 ‘Esmeralda’ ‘Esmeralda’ 37/6 ‘Galestin’ ‘Esmeralda’ 36/6 ‘Esmeralda’ control ‘Galestin’ control ‘Hexe’ ‘Hexe’ 76/20 19 ‘Esmeralda’ ‘Hexe’ 46/20 17 ‘Hexe’ ‘Esmeralda’ 42/20 19 ‘Esmeralda’ ‘Esmeralda’ 31/20 12 ‘Hexe’ control 0/20 0 ‘Esmeralda’ control 0/20 0 total numerator: of diseased plants inoculum ‘Esmeralda’ ’) with origin. the Exobasidium cultivar cultivars Azalea different on 0/6 0/6 of number denominator: galls; number of inoculated plants. less was the Though galls latter narrowly not the on on 8.2. Cross different less from which it certain ‘Hexe’, on originated. Exobasidium occur, on on related and (1959) Azalea by Woronin. Exobasidium with closely Savile to occurring described This this does single species, *J t japonicum Azalea varieties, as If genicity. be may they from cross the with to different Vaccinium Pure mean if the authors, with based even originating the on they Exobasidium Exobasidium are vaccinii morphological considered that the Exobasidium strains and occur of with pure Azalea vitis to be occur- specialized in their patho- some Exobasidium performed with cultivar Vaccinium ‘Hexe’, vitis of Exobasidium cultivars biotypes To from isolates they investigate different cultures obtained pure Dutch the Graafland the latter cultivar (1953) pre- by inoculating vaccinii. experiments described in this paper of Exobasidium and or plants. from idaea. obtaining infections of cultures races different host japonicum of Exobasidium vaccinii were obtained from obtained from idaea. cultures The brown be not physiological on were Azalea from culture pure might Cross inoculations in the performed is opinion different character succeeded in a plants inoculations Belgian ‘Esmeralda’ viously are expected parasitic origin, other spores plants ' X' different host on ring not host identical are similarity of these fungi. However, it to seems Conversely, infections cause the cultivars specialized inoculations According species the to parasite may attack Azaleas of different genetic composition. from a Japanese cultivars. able was specialization some certainly the the higher degree than to a even is provoke to apt fungus from of colonies both of fungi the on former agar showed produced a a different dark aspect. discolouration THE PARASITISM OF EXOBASIDIUM SHIR. JAPONICUM ON 365 AZALEA of the nutrient agar. The light yellow colonies of the latter hardly changed the colour of the agar. Both parasites also showed a difference in colour of the nutrient solution when grown in shake cultures. From inoculations it cross attacked not was Azalea does The results. function not In Vaccinium. became clear that Vaccinium vitis idaea by the Exobasidium from Azalea, and that conversely 6 all results of as of sets host a plant experiments of these sets one of the to fungus all made, were living on with similar experiments given in are table 5. Table Number of plants with galls resulting pure c origin ons,n of cultures from 5 Azalea and of inoculation of Exobasidium of different origin; 20 .1 plants , the :li' culture plants test Azalea Exobasidium japonicum if if if if if if if number of number of c “ diseased galls plants cultivars: 25 25 17 ‘Hexe’ ‘Hexe’ 40 40 19 0 0 0 0 ‘Esmeralda’ 0 0 0 ‘Hexe’ ‘Hexe’ 0 0 0 22 15 Azalea vaccinii vaccinii idaea each set. ‘Esmeralda’ ‘Esmeralda’ Vaccinium Vaccinium if vitis in of number "u pure pu,c c Exobasidium Vaccinium test vitis vilis idaea cultivars: cultivars; Vaccinium Vaccinium idaea idaea vitis vilis their a there is difference in Despite morphological similarity, pathogenicity between these fungi. It is possible, therefore, to consider them to physiological represent vaccinii Wor. and the difference in of sufficient for name the fungus standpoint that the It is American Ellis not available. different ferrugineum On malt agar this wrinkled was surface and ‘Hexe’ galls appeared. as parasite pure from from therefore, is not a culture of the Swiss no complete, it be may rather vaccinii a than this pure opportunity with Exobasidium from this Rhododendron must also Rhodo- to and finely yellow or but no culture, inoculate Rho- ‘Hexe’, and the evidence, be assumed that the considered 1953). Wor. more a were Rhododen- (Graafland, Exobasidium grey-brown was Swiss specimens of the latter inoculated with Though there dodendron ferrugineum form. in differs with was we assume Exobasidium inoculations carried out with cross from Azalea and rhododendri, obtained fungus and japonicum Shir, in developing colonies with brown colour. lized of incomplete, Exobasidium be valid japonicum Shir. least if Peck to too. set originating remained fungus then the be Exobasidium at of the considered are species, Exobasidium azaleae that the dron Exobasidium more Azalea would species are regrettable species on distinguish to Exobasidium species, viz. one is taken up in the present paper, Exobasidium cultures dendron of of the pure cultures aspect importance This discoideum races If, however, the physiological specialization as a fungus from physiologically specia- 366 W. GRAAFLAND CHAPTER DEVELOPMENTAL STAGES FECTION Efforts WITH were developmental infection OF made stages obtain to of the For that BUD information leaves At develop. to different intervals removed and mental Exobasidium an stages could be studied young 1, 2, 0, after 7, IN- POSSIBLE concerning are the sensitive to buds of axillary suspension imme- inoculation the leaves and the 3, 4, 5, WHICH and the buds had started fixed in Graf’s solution. of the which dormant purpose diately after the shoots had been decapitated were AT JAPONICUM IS more young inoculated with were THE EXOBASIDIUM by this fungus. Azalea shoots IX In this of the progress axillary buds the way develop- gall formation 14, 21 and 28 days after the 10, inoculation. Microtome the infected chyma proved observed. leaves young differentiation intercellular between to be spaces, showed the hypertrophy palissade are leaves. already spongy All paren- In a few cases hyphae were visible in the though the process of penetration itself was not it However, sensitive hyperplasy. the lacking. The small size of the young and and layer blastospores them between the hairs and the scales the days after the inoculation slides revealed that within 4 to made it which became infection when clear they difficult the cover that the to detect epidermis of young leaves still enclosed in are the bud. The aim of the the Fig. period 7. following experiment during which A-D: development the of b -b x 3 : young an axillary leaves. was sr s 4 bud : study to leaves could still of Azalea bud scales. the length of be infected. For indica, cultivar ‘Hexe’. THE OF PARASITISM EXOBASIDIUM that purpose in 70 Azalea in order after stimulate the to this the in plants found that leaves was next that of stage were the laminae are of galls stages i.e. number at in galls of mm 10 the shoots. of of number plants galls 19 3.0 30 25 4.0 17 8 30 6.5 42 10 9 40 8-10 1 1 50 12-15 0 0 development which at in another way. inoculated with a had not appeared time of inoculation marked. those on galls were soon as are this in with length 5 with to least weeks 42 after developed and at the the just large enough that of the former infection in spread to paint, After be to at those leaves which on agreement begin the 4th the last being had only susceptible the laminae infection, to Exobasidium; treatment. in mm of shoot which present subject just visible leaves of 40 marked were leaves about 8 is of the for were This result culture pure tip small too the leaves experiment: As The young The inoculated leaves were leaf is still a of with plants group 10 they stage. per developmental different 10 leaf reckoned from the be number buds in decapitation 85 inoculation. Twelve to inoculated the 70 inoculated. galls (Table 1.5 of It In and out, infection to 2.5 were when spread to 0 stage plants infected. 11 studied also visible culture pure 6 buds after moments axillary decapitation The axillary length of the days after was of different of a of inoculations. 1, C-G). the leaves on begin removed were could be longer susceptible no Table Number with set still length mm development 6; Fig. 7 and Plate used for each 367 AZALEA different intervals the buds. At inoculated were of 8-10 the leaves stage buds ON tips of the shoots unfolding of the unfolding, of Exobasidium. Ten the plants SHIR. JAPONICOM juvenile a infection out, is no important to longer possible. From answer practical a the in dormant buds. In on or be infected start buds is leaf was kept with a marked below at the it especially was and, the An with paint. marked long Nine was groups, In On leaf already before experiment culture. may galls long before the growers therefore, inoculum. pure the Azaleas greenhouses broken. administered inserted then of view spores of Exobasidium pruning, or inoculated visible were the axillary artificially buds by cutting of the were point question how long inoculum of Exobasidium remains viable each every the dormancy performed with each plant shoot of the the inoculated. plants, 5 youngest 4 axillary plants high humidity for 30 hours. At different intervals, were The 4 weeks after the inoculation, the tips of the shoots were removed up to just above the marked leaf to stimulate the development of the buds. It appeared that even buds inoculated 4 weeks before they began to 368 W. showed expand, experiment the development in the tips of the shoots within inoculation, longer inoculation for viable, a gall repeated was of galls after year the experiment were dormant buds of the had been with an on treated Exobasidium with the the appeared suspension be to half (Table 7, 7 begin in each group. number of number of plants galls with galls expand 0 17 5 2 20 5 3 18 5 5 16 5 9 10 4 12 7 5 18 3 3 23 4 3 30 4 3 14 4 14 24 11 5 28 5 3 35 11 4 56 2 2 91 3 3 119 2 2 182 4 2 2 after different intervals the to 1 shed experiments at suspension; five plants inoculated buds light no the on question how fungus the during the period between the inoculation and the develop- behaves of the their and gall, that the possible on the after of days after ment 4 weeks after still fungus leaves developing young Number These 6 The months most Even 1). removing 2). inoculation experiment instead of found in buds that remained dormant for galls occurring experiment experiment the at chosen. Table Number way, period of a 7, but (Table same intervals were they GRAAFLAND how it blastospores and surface, that between the hairs and of the leaves young the the colonies scales the may obtains administered occur at of the the buds formed thus the nutrients. necessary to remain dormant buds. time the buds It is budding start viable Penetration begin expand. to However, it is also possible that the spores penetrate directly into the leaves of the dormant inside Which as the The buds latter of these first rate which and the is two as pathways long development stimulated parasite takes environmental of the as is actually developmental stages of of the symptoms are bud, and that the development of the hyphae delayed new place. growth, Thus conditions: remain remains the disease could the host plant of the disease will to buds taken, a appear. parallel the incubation if the buds are not determines dormant. undecided be detected. the time If infected development period depends just unfolding at at axillary of host on the the time THE PARASITISM contamination, of the after the infection but after OF the EXOBASIDIUM the symptoms THE frequently White, done the been of “Tuinbouwgids” with Jaenichen, galls the (Dutch still Guide) though it is known that they are The recom- conclusive not 1957). This method would be satis- removed were mixture. i.e. time, in picking before of mature sporulation, galls promotes spread of the basidiospores. However, it is impractical to remove gall bearing leaves sufficiently early from large numbers of densely Azaleas. planted buds cannot be control of the could It easily is state For duced into other buds of and forbid its 10.2 countries, laws, by (1928) also which In with spraying (1925) consider (1954) the removal of the the use as are it is dormant to easy defeat parasite dangerous a un- easily be intro- prefers a a or Cole be to good zineb after (1944) an Ciferri been pruning; (1953) carbamates had the and Thiel effective preventive treatment with galls. Anonymus (1956) frequently of lime after use prefer Bordeaux mixture, (1929) sulphur. as has fungicides spray; mentions fungicide. following good results by spray- galls had been removed possible. mature control fungus plants apparantly hidden in manner mixture of lime Many authors consider insects from an places. the once, may be may mentions lime. Bordeaux ing with copperoxychloride as it recommends the zincethylenebisdithiocarbamate far japonicum this the list and Marchionatto Thiel recommends Jaenichen neighbouring galls only fungus contamination the time the dormant buds because though Marchionatto also (1951) new fungicides literature advised. Marchal Miles from continual a importation. Control the In at Exobasidium imported Azalea plants. quarantine a imported from Belgium in galls reason in Thus Even if the necessary. the infected expand, to ones. greenhouse, a removing Plants begin healthy blown spores after show may that from way from that be diseased. folding. the distinguished occur healthy they from unfolding buds would be obvious may still before Moreover, eradicated in this were as Bordeaux Horticultural when the colour is still green, but the all with spraying 1952; Graafland, the if 1909; Miles, 1928; 1954). This is sometimes (Naumann, out 1951 ; 1960 mends these measures, factory THE DISEASE importance of removing and burning the galls pointed combination (Welvaert, period. measures 1933; Stautemas, in that days longer or X CONTROL OF In the literature has 369 AZALEA appear within twenty may if the buds remain dormant for infection, Hygienic ON they may also be delayed for 6 months CHAPTER 10.1. SHIR. JAPONICUM of galls insects to to other parts is important be effective in of the plants. (Stautemas, transmitting spores For 1951). that Next reason to the insects 370 W. mites be this be might killed opinion and involved, (Miles, Aleurodes of these parts vaporarius from galls In the glasshouses whatever fungicide a and keeping x is that the are the minating also less of and become in 1960 sulphur as _ A drawback sale. vitro Horticultural advised for out were captan, unattractive for disastrous. (Dutch are going more and way well as severely damaged by such frequent fungicides lime and zineb shaped spores is of use, Guide) As these spraying. of some assayed against when used in fungicides a were the centrations in high the the newer Exoba- only a the E.D. small growth are Even if would have different from be to be blastospores could to 1/100 of they occurs could the experiof the cultures. The determined were those be inoculated concentrations following fungicides 1/10 as condensation-water, basidiospores the nutrient solution of shake The budding. basidiospores, thin film of a humidity. of the culture used in the number of ger- percentage 50 of the be suspensions. Budding only watery difficulties, to mycelium. varying shake a hardly can high numbers of spores needed for these added they vitro, in which hundreds of Azaleas avoid inhibition of the weighing all obtain the to To ments. at assess as covered with are spores kept to at assaying, in order tests in in developing but numbers, counted, impossible when the blastospores large germination germinate not i.e. or more irregularly ordinary It is or period of flowering is with be obtained in can more spray this _ Septoria azaleae Vogl. as in disease the Exobasidium from regularly, even growers succeed and irrigation. spray of the buds with applied be to Some our arising disease. The do are the i.e. compounds, sidium free “Tuinbouwgids” fungicides have compounds, copper by _ compounds regards Though it is by draughts protection 'X' Experiments copper augmented pruning. parasitic fungi, such during the In after They shed their leaves, Spraying carried droplets Fungicides or plants plants sprayings. 10.3 with their (1925) role in the transfer of Exobasidium a aired and are before v_» from other water necessary. fortnight every in is to the bodies spread of the spores. way contamination occurs, alone not therefore, healthy parts of the plants, the disease is in to opinion mainly spread by when Marghal arthropods. possible that insects and mites play spores should, too 1929). Marchionatto based basidiospores attached the causing as animals these and Marchionatto, 1928; his observation of on mouth the GRAAFLAND used used in in practice: copperoxychloride; 0.05, 0.10, 0.20 0.50 g/1 lime 0.075, 0.15, 0.30 and 0.75 cc/1 0.025, 0.05, 0.10 and 0.25 g/1 0.02, 0.04, 0.10 and 0.20 g/1 sulphur: zineb 1 captan The ) 2 ) experiments were carried out in J ) zinccthylenebisdithiocarbamate. 2 ) 4, 5- cyclohexene -1, 2- dicarboximide. erlenmeyer and by con- flasks containing PARASITISM THE 50 a of cc EXOBASIDIUM OF malt solution a which known to standard solution had been added. oxychloride prepared were Table the of Composition media in cc 0.1 cc of solution in 40 10 0.1 50 30 20 0.2 50 0 50 0.5 nicum shake culture well cultures mycelium with latter 110° C for the g/1). in even the inhibited fungicide growth fungicide was concluded was sulphur that most were weeks, 3 as controls. quantity test a at of temperature The weighed. the at growth of stimulated at effect this of (Fig. captan was were suppressed concentration mycelium, the be of to seem any growth. Though captan in concentrations of 0.2 degree influence favourable the not The 105° C- experiments highest the cc/1. Zineb did high a no used cultures paper. concentration a fungicide Since 8). of 0.1 and that is the latter chosen for the g/1, g/1. of now experiments It lime less with plants. 10.4 Experiments was Captan of Azalea day, shoots shoots the suspension. a the inoculation. buds day removed In treating would exercised its fungicides treated with were of Exobasidium. were before with in used in concentrations and after culture a /2 inhibited the even to of widely used in practice, test if mycelium sulphur also japo- the used were to It turned out that copperoxychloride concentrations of 0.15 this x covered with filter dried was Exobasidium an determined. The was and then days, of the Lime influence; this 7 three times. growth (0.5 mycelium to addition for 2 Buchner filter a of cc suspensions without fungicides added. Similar developed, to 1 flasks erlenmeyer Thus solutions way. the solutions that are similar a value had been shaken through 3 replicated the all was which had filtered were prepared in malt solutions without any as all After 0.05 in nutritional equal used. To normally of cc 5 were g 1 per 50 obtained in concentration 45 The other media as chloride a 50 were copper- copperoxychloride. standard % and of water containing 8 used quantity 371 AZALEA table 8. copperoxy water in in containing malt solution ON quantities of The media indicated as SHIR. JAPONICUM on In which one the they was were on inoculated experiments The buds g/1. 1 fungicide before, of the tips inadvisable to plants with captan, develop g/1 and their fungicidal infections action. total of 36 buds. From were remove as in before that the In each series 4 4 control plants the the 10 tips case plants tips of a the captan the same pure fungal days after long time unfolding could were the a tips of the the removed the with simultaneously with the application of second series It the series vivo of 2 have used with shoots were 372 Fig. W. 8. basidium d: Influence japonicum of fungicides on in shake cultures, captan. Dry-weight of the centration in GRAAFLAND the a: dry-weight of mycelium copperoxychloride, mycelium without fungicides g or cc per formed b: lime sulphur, 1; ordinate; weight 0.52 in g. g. by r. Exo- zineb, Abscis: con- PARASITISM THE removed control OF EXOBASIDIUM with simultaneously this plants The smallest number of 2 g/1 the done was of 10 with the after inoculation with on of suspension a from 4 other inoculation. captan suspension a also used in (Table practice. 9 of 4 groups 373 AZALEA fungal suspension that is one Table developing the when galls appeared 9). The concentration of 2 g/1 is the Number of galls after ON and inoculation, days applied simultaneously was SHIR. JAPONICUM Azalea plants with 36 and Exobasidium japonicum buds in total, with treatment captan. of tips removed time of with relation inoculation to 7 days later 4 controls: plants 34 4 From these when not with the g/1 tips the reach the between the or one 1 0 8 6 23 13 removed removed it days became after began clear killed was the buds, because some minor solutions experiments been tested in lime plants The test were composed of 4 main series the sprayed of 10 5 the time of infection. This to danger glasshouses Instead of seems as be the captan were could hidden fungus had already was applied. these experiments the of where g/1 after after the inoculation, and that treatment. Each series 30 total about axillary buds. The 10. showed that fungicides provided that they means is sporulating the recommendable. are that the buds should infection spraying frequently, more adminis- cc/1 week one control, keep protected, 7.5 days experiments under at those galls was became visible g/1 with in table to in fungus plants in 2.5 sulphur decapitated indicated buds used: were were the case the latter the In vitro. 24 galls. performed with the other were copperoxychloride be inoculation: when the latter captan Perhaps because or in that, by captan inoculum, unfold. to blastospores zineb The 9 the inoculation: with the inoculum. If of the that had fungicides is 14 with simultaneously 10 week after sprouting scales In addition result g/1 19 29 into the young leaves before the captan penetrated was 2 g/1 3 fungus the infected buds the shoots 1 15 tips simultaneously day one following of 20 experiments dormant, added tered the days inoculation galls plants remained was with shoots 10 concentration 14 8 later day 2 42 simultaneously the captan g/1 before 1 after captan 1 days of tips removed of concentration time 2 shoots inoculation in with captan the simultaneously treatment always galls application Discarding of able continuously present, occur are administered particularly frequently. hygienic the young measures galls before 374 W. GRAAFLAND Table Number total of after galls developing on inoculation with 10 of 4 groups of suspension a with Azalea number of zineb tural to the destroys Guide). However, it is also pruning infection. This “Tuinbouwgids” difficult pick to when all young out apply sporulating galls Horticul- galls the at fungicide a are found. resumed after growth is vegetative has practice (Dutch grower may when especially important after or is of source the in addition the Therefore, infection, prevent Spraying galls 24 plants recommended in proper time. in treatment 11 sulphur control sporulate, and 8 lime been axillary buds 3 copperoxychloride they 30 fungicides. fungicides also with plants Exobasidium japonicum have been taken. cuttings CHAPTER XI DISCUSSION ON THE RELATIONS BETWEEN THE GENERA EXOBASIDIUM, According dyana compose siders this which the to surface the cuticle. only host a are of subclass class of lacking and this presence the exposed genera there is as and also the formation sporidia Ustilago of arising hordei in the colonies; from (Pers.) the budding this smut Lagerh. spores blance between the characters shown species when grown in pure develop colonies In Ustilago gation of caries as 4- (D.G.) they arc with species and Tul., a culture wrinkled the process —- sporidia. conjugation formed. In this In Kordyana (1954), assigned to the basidiospores one of of the the to Ustilagi- is an agar resulting budding species, Ustilago there budding the in be a striking and of e.g. by of such are in the as resem- Ustilago medium. Both fungi folded surface. or occurs way authors, Talbot by Exobasidium on of some the bursting that the Exobasidiaceae of their Moreover, below the resemblance reminds hymenium a just e.g. must nales. This resemblance is found in the fact parasites, of Exobasidium and Others, a The Exo- assignable and by character primitive Agaricales, Basidiomycetes. developed becomes Korcon- order Hymenomy- is genus Exobasidium Hemibasidiomycetes, the and (1952) the order to the Exobasidiales. the Exobasidium basidiocarps, hymenium (1949), assign that the of account on this order: opinion forms, plant Because separate belonging seven TAPHRINA Alexopoulos synonymous with Holobasidiomycetes, basidia; Viennot-Bourgin to of one primitive of of be others is AND genera Exobasidiaceae. subclass are the (1949), family to Agaricales consisting the family the basidiaceae to the according of cetes Gäumann to TILLETIA USTILAGO, genus is followed Tilletia, between the these e.g. by conjuin sporidia two* genera a Tilletia as soon dicaryotic THE mycelium has is point the in of point who fungi eventually, or, both In the The In the A dermis and the both cuticle of the the show the of the kind same Laubert (1932) genera of tomical picture: and spaces infection In the to be n in In coarse and Exobasidium japonicum Taphrina, genus exceptional. In in species, however, genera exists of asci in mainly those was The hyphae, budding not hyphae. He agrees Thus, yeast depends the with the by' in arc used (1949) infectious. the like but not used cultures constant, Mix do of both cells. on cases Mix’s term Exobasidium. On the other hand A Voronin cells to “conidia”. It borne on spores seems, however, conidiophores, as is latter between the former genus 'are this to family. cultivating Exobasidium for growing Taphrina of consisting of these short of the for that thus be to taken the are budding, by restrict customary yeast-like spores Taphrina (1867) called short hyphae nutrient solu- these these similar in preferable it of blastospores or of alike, can Taphrina 1935). In the multiplication arc “blastospores” and members (1934) the seems — J the composition development, found. contrast in is J was in length Fitzpatrick mycelium genus Exobasidium and “blastospores” shape and the infectious character Exobasidium. on are The Ericaceae (1949) The the name the (1953) Mix hyphae the difference species of occur by Graafland originally species. The J ascospores of basidia in the ana- spaces. spores Sadeb. The same copulation (1949), 1927; Mix, rare. representatives which Taphrina, is Taphrina. on method used species tion. presence genus parasites of 1 he the in the conjugation of — (Wieben, the the cases spores;y Mix deformans (Berk.) Tul. show copulation of derived from the ascospores both epiphylla which occur with few intercellular copulation to Taphrina and in living fungi the intercellular A 1912). representatives show galls authors members Juel, the their way of haploid according Only in The no of epi- epidermis. some 1897; parenchyma grow the budding. that In both genera chloroplasts. width, shape spaces group of which the (Thomas, brooms. by occurs astonishing one by monocaryotic, occurs dicaryotic. of scarcity a 0.5-1.0 thin, uniform, a intercellular analogy between plants. galls and also witches’ the spores parasitism the host on similar a sporulation. not to mentions the too by Wo- similarities: important of a striking a out underneath the or Taphrina and Exobasidium their influence cause galls it is belong to in time of germination of the genera show develops either between hyphae at Though related from pointed galls cause myce- another brooms. of burst cases consider both following They is Ustilaginales. closely been already the conjugation dicaryotic a conjugation not are mycelium lives layer cuticle is has Considering these similarities is however, of 375 AZALEA cycles of both fungi parasites; witches’ cases tissues. This mentions true are Taphrina the life view, resemblance. (1867), Both 3. This lack plant. and ON it is known that of difference between Exobasidium and the ecological , SHIR. JAPONICUM Exobasidium, genus though the host genera Exobasidium ronin 2. EXOBASIDIUM the observed, present taxonomic 1. OF formed. In been never lium is PARASITISM and in over for sprouting this name nowadays. 376 W. According Ainsworth to should be confined and where Uredinales, of the gation Therefore, When genera differ used the comparing are borne formed in asci. which this the it of of these with group it is also given Taphrina well as able to one exogenous spore their host these 2 living. for stops, genera with group of blastospores the as infect to are basidiospores The more. Taphrina, the they both may form By sprouting once are the genera as Exobasidium In in the both plants. of the are endogenous formation have developed. possible that the similarity in behaviour between the taxonomically mode important development of the spores, has been induced by their parasitic of by of that concluded view. fungi belonging different in so groups, “blasto- term definition here the difference similar. origin, and that, by differentiation, and another by conju- representatives basidium; a genera, that the imagine However, the be must However, ascospores , same the paper with point on sprout may formed in both can in character of Taphrina, taxonomic a exogenous, Exobasidium One followed which has been budded off”. parasitic the behaviour of these spores is are is budding accordance spore and from blastospores, “sporidia” term biologically very similar. This is remarkable, are endogenous, that of confusion, in “a Bisby: Exobasidium widely spores the process avoid all been Ainsworth and genera the (1950), sporidia. to has spores” and Bisby secundary spores formed by the Ustilaginales the to GRAAFLAND of way ) SUMMARY The 1. purpose japonicum Shir., host and plant important to parasitic For 2. of frequently (Belgium), of the soil. x a cell the time and as well life also paid of cycle this some as Woronin Rhododendron genus the cultivar cultivated are to as sprayed. ‘Hexe’, during The were ‘Galestin’ Exobasidium parasite control the to its measures question of Exobasidium chosen and the vaccinii, as mainly and experiments host plants. ‘Moederkensdag’, grown the greater part of temperatures, high humidity, frequently the manuscript of this Gottgens von besonderer of suspensions the length Exobasidium Azaleae Beriicksichtigung of Daucus pure of the in Ghent the high moisture were year in content performed with cultures. As was E. und ready 1960. seine Infektion gallenbildenden pure to be sent to the Untersuchungen printer iiber die Wirtspflanzen der Wirkstoffe. Phytopath. Z. cultures of the Azalea parasite in synthetic basidiospores as well as with Environmental conditions proved to be of influence infecting incubation Peck der the host period. activating substances, carota roots. paper appeared (Gottgens, and succeeded in filtrates contain or was ‘Esmeralda’, 394-426!. This author obtained media on is viz. Boskoop, low studied, the relation of idaea. used. Azaleas Water Entwicklung 38: in The described by cultivars of the at rather of study unter that Japanese origin grown were study to cuttings. At ) study vilis was Azalea. on Attention growers. with fungus were greenhouses investigation of infection commercial this Cultivars rooted the mode Vaccinium on this fungus parasitic a of this identity of plant with Further Gottgens found which promote the growth that of growth stimulating factors probably biotin, nicotinamide, inositol and pantothenic acid are present in the the culture tissue cultures nicotinic acid filtrate. THE 3. The visible leaves and enlarged, are called are with covered 4. The the (Fig. the leaves. latter produce of hyperplasy of of the parts the them give number cells mesophyll media malt and malt-saleb also be and more The 6. malt a less or solution regularly developed were spores in grown in in grown be to shake a most this increase considerably to galls The cell In culture. could be leaf a also was it of tissue and culture could fungus short ways cells, hyphae resembling blasto- not well as the shoots the of with as sus- of the plants inoculated axillary formed the newly shoots appeared of the inoculum, whether basidiothe influence to seem of their become fungus cells neither number of of between basidiospores 4 nor In that least at case would be one were that had fungus + and and one either from able 5). between one spores — cell fusion penetrated into — basidiospore, accomplish infection. to necessary originating single basidiospore of -+- and possibility, the after or presence The (Fig. 6). the leaf appeared that blastospores it investigated. was uninucleate (Fig. basidiospores and blastospores originating from blastospores, a dicaryotic be to sexual differentiation the a investigated. culture or from shake the the surface galls (Table 3). Thus, of on blastospores appeared fusion occurred no on combination However, of the case expected, might take place a did culture, between basidium, where in or both fusiform source fusion could be observed, Even blastospores. the of galls The 1). (Table which at stage basidiospores and vitro no In The hypertrophy cultures. As pure inoculated with basidiospores number shake a which (Table 2). 7. The from cells or spores both B). 3). were the treatment and basidiospores favourable. The pensions obtained from shake cultures. Simultaneously in order to stimulate the were decapitated development buds. By five to blastospores by budding. shaped, eventually (Fig. dormant buds were appeared agar become A (Fig. 2). occurs Colonies of Exobasidium japonicum 5. of they 1, forms basidia, four leaves remains undifferentiated; leaves these hypertrophic (Plate fungus the on even of the after ripening bears basidium 377 AZALEA appear appearance of the mycelium may crooked; green, velvety a Each great a are ON diseased parts The and convex stage they intercellular dicaryotic, attacked become japonicum buds. unfolding young which spores, The 1). of the a SHIR. JAPONICUM Exobasidium by of the blades In galls. rupture the cuticle EXOBASIDIUM of attack first signs youngest just parts OF PARASITISM single a to induce the cell out development be concluded that Exobasidium japonicum is homo- must thallic. 8. By Vaccinium vitis (Table 5). Exobasidium and idaea, This in colonies inoculations it cross difference vitro, are japonicum appeared that Exobasidium japonicum that in Azaleas Shir, is accepted 9. The after leaves the susceptible tip until C-G and Table fungus on the 10. by was as to the valid in difference a importance, name for attack not colour and for this the of the reason Azalea parasite. on the two host Japanese Azaleas and from the plants, proved to be identical in (Table 4). are bud. By inoculating i.e. specific did Exobasidium vaccinii by isolated from the crossinoculated cultivar ‘Hexe’, be of to attacked not added pathogenicity, considered Strains of Exobasidium japonicum pathogenicity. were still probably susceptible the leaves of the they 6). In shoot at different had 6 months, infection removed, length of while after the it was 8-10 shown mm buds treated with as after removal still enclosed buds began that (Fig. 7, a spore of the to they in the unfold, remain A-D; Plate 1, suspension, the tip galls appeared (Table 7). The dormant buds should spores. a dormant axillary viable after unfolding leaves wind-borne been have reached to intervals Of the be protected by following fungicides a fungicide against infection different concentrations were to a shake culture: copperoxychloride, lime sulphur, zineb assayed by adding them and captan (Table 8). Captan strongly inhibited the growth of the mycelium at 378 a W. concentration of 0.2 GRAAFLAND Buds g/1 (Fig. 8). The number and the fungus inoculum 11. The genera galls appeared Exobasidium the to the Taphrina the groups, be to after shoots reduced strongly most treated were inoculation with a spore when with this suspension. the fungicide applied simultaneously (Table 9). were between similarity Exobasidium and taxonomic of of Azalea on and fungicide before, simultaneously with, is life and Basidiomycetes and cycle striking, Hemibasidiomycetes ecological the though they the is are behaviour of the placed in quite different The Ascomycetes respectively. also relation discussed. REFERENCES G. Ainsworth, C. Alexopoulos, Anonymus. 1956. O. Brefeld, 1952. J. Diseases Die Bisby. of Azalea. of the 1954. A dictionary Introductory New Mycology. fungi. Kew. London. York, Gaz. New South Wales Agric. Unters. Gattung Exobasidium. 67; Gesammtgeb. 583-584. Mykologie 12-18. 1915. The Thelephoraceae of Missouri Bot. Card. A. R. Ciferri, R. and G. 1889. 8: E. Burt, C. 1953. anni Cinque 2: di North IV: America Exobasidium. Ann. 627-658. esperienze anticrittogamici con sulle bisditiocarbamato di zinco. Notiz. Malat. delle etilen- base di a Pianta 23: (n.s. 2) 3-19. Cole, J. R. P. Eftimiu, and Rev. B. Ellis, J. S. 34; 1874. F. Ezuka, A. I960. 1955. Recherches 14: Agric. of fungi found species in Pareys culture of two Phyto- histologiques sur les Exobasidiees. 62-88. at Field. New N. J. Bull. Torrey Blurnengartnerei 2. of species Shirai. Bull. Tea japonicum Sc. Bot. Aufi. Ex. Exobasidium: Div. Tokai-Kinki 2: 240-265. vexans Massee Stat. Agric. Exp. E. and Brit. found of fungi in the vicinity Bull. of Boston. Bussey 247. 1934. The life Botan. Mykologisches. C. and history parasitism of Taphrina deformans. 14; 305-326. Agric. 1861. H. List 1878. 2; R. Fitzpatrick, L. Azaleas. 28-53. Inst. Gadd, C. 1927. Ent. et Rhododendron Farlow, W. G. Fuckel, on 45-46. Artificial and Ex. 3: Vdg. New 5: mixture controls leaf gall 354-355. Kharbush. Path. Club Encke, Bordeaux 1944. Low-lime pathology A. Loos. Soc. Myc. and 1948. 31; 19: 249. Exobasidium of vexans. Trans. 229-233. 1949. 'The . Zeit. The basidiospores Exobasidium fungus Tea vexans. Quart. 20: 54-61. and A. Gaumann, E. Graafland, 1950. —. Exobasidium W. 1949. 1953. Die Pilze. Four Further Trans. vexans. observations Brit. Myc. Soc. the on 33; spore-growth of 19-21. Basel. of Exobasidium species in pure culture. Acta Bot. Need. 1: 516-522. . 1957. Exobasidium japonicum Gent St. H. Grootendorst, M. T. Hilborn, H. 54: Juel, H. O. 1909. des 8; . vaccinii. The Bot. zur Azaleas, Schadlinge Kcnntnis der Tidskrift 6: 46: in Hogesch. cn Opz. Boskoop. der of lowbush blueberry 241. dza/rentreiberei. Gartenw. Gattungen Taphrina und Exobasidium. 353-372. Uber eine Exobasidium-Krankheit Apfelbaumes. Mitt. Kaiser!. Biol. der Anst. Azaleen und den Mehltau Land- u. Forstwirtschaft 28-29. 1925. Die “Klumpenblätter” 1932. Exobasidiinae. 3: en mode of infection Phytopathology — Pflanzenkrankheiten. Gartenw. . Med. Landb. 275-276. 1912. Beitrage R. Azalea. Rhododendrons Hyland. 1956. 1954. Krankheiten und Svensk Laubert, 1954. J. and F. op 547-553. Exobasidium by Jaenichen, 22: 282-296. In P. Krankheit 29: der Azaleen und verwandte 428-430. Sorauer, Handbuch der Pflanzenkrankheiten the parasitism 1913. Exobasidiinae. Lind, J. C. L. Lockhart, C. E. 1925. Mix, H. A. ■ 1928. W. J. de shir, on 379 azalea 350-352. Fungi, Copenhagen, of PI. lowbush blueberries. Dis. 28: 22: 63-68. Paris. Pathologie vegetale, nueva la Argentina. Bol. para Min. 469-474. in culture Azalea 1935. The life history of 1949. A monograph of . disease red leaf 1929. Una micocecidia Nac. Agric. Danish Rostrup, on causitive fungus. Tea Quart. Elements Marchionatto, J. B. Miles, In E. japonicum 764-767. The 1951. A. Marchal, exobasidium 1958. Studies 42: Rep. Loos, of Belgium. J. Min. 35; Agric. 137-147. 25: 41-66. Taphrina deformans. Phytopathology Sc. Bull. Un. the genus Taphrina. Kansas 33: 1-167. Naumann, A. 1909. Botanik Peck, Ch. H. of Petri, D. Sc. H. galle fogliari Ann. im pontica di Azalea 5: Myc. indica prodotte dall’ 341-347. II. De cultures belangrijkste Sandomierer Walde und ihre Parasieten. 385-391. Emden. van bladpokkenziekte De 1949. de van thee I. 218-231. 1949. . and De bladpokkenziekte De bladgallenziekte van de thee II. Bergcult. 370-377. and H. 1950. . Theecult. Arch. vaccinii. 1901. Bos, J. 17: 1896. Notes M. basidium Ritzema sulle Cracovie 18: Bergcult. Richards, New York State Museum Rep. Handbook der Bloemisterij. 1909. Azalea Ac. J. and J. 18: botanist. Ann. glas Doetichem. M. Bull. Reitsma, the discoideum Ellis. 1955. van. Ang. 72. Osservazioni onder Raciborski, 26: Hist. Exobasidium Raalte, Ver. ifWodeni/rorc-Schadlinge. Jahresber. 171-188. 1874. Report of Nat. 1907. L. iiber Einiges 7: van de thee in Indonesie. 71-76. cultures on Bot. Gaz. 21: of Exobasidium andromedae and of Exo- 101-108. Phytopathologisch Laboratorium “Willie Commelin Scholde inlichtingen, in 1900. Landbouwk. gegeven ten”. Verslag over Tijdschr. 9: 65-125. Savile, D. Shirai, M. B. O. 1959. Notes 1896. 10: Mag. Tokyo E. Stautemas, P. Talbot, 1951. H. B. De Exobasidium. Can. J. Bot. on of Descriptions some 37: 641-656. Japanese species of Exobasidium. Bot. 51-54. bij oorkensziekte 1954. new Azalea. Tuinbouwber. 15: 89-90. of lower Micromorphology Bothalia Hymenomyceles. 6: 249-299. Thiel, J. Thomas, 1951. Zwamziekten 1897. Über einige F. 6: Tubbs, F. de Azalea indica bij Exobasidien und 1947. A leaf disease A. Vandendael, 41: 1960. De export of tea van 1952. 1933. R. P. Entom. De 26: T. Quart. 19; 43-50. Tuinb. parasites oortjesziekte. Rijksst. des Plantenz. plantes Gent. cultivces. Paris. Leaflet 48. Infektion, die Geb. Forsch. Myzeltiberwinterung, und die Kopulation Pfl. krankh. und Immunitat im Pfl.reich 139-176. and F. basidium Woronin, Tea Ceylon. 631-640. Die 1927. 3: F. to new The insects and diseases of Rhododendron and Azalea. J. Econom. bei Exoasceen. Wolf, Hand. 17: 494-496. 157-161. W. Wieben, M. en Belgische sierteeltproducten. Belg. Viennot-Bourgin, G. 1949. Les champignons White, Cult, 305-314. R. Welvaert, L. Exoasceen. Forstl. Naturwiss. Zeitschr. M. A. Wolf. camellias 1867. Freiburg 1952. var. Exobasidium 4: 397-416. Pathology gracilis Shirai. vaccinii. Ber. of Camellia leaves infected Phytopathology 42; by Exo- 147-149. Verhandl. Naturforsch. Gesellsch.