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Genet Resour Crop Evol (2011) 58:831–835 DOI 10.1007/s10722-010-9620-2 RESEARCH ARTICLE Manihot fortalezensis Nassar, Ribeiro, Bomfim et Gomes a new species of Manihot from Ceará, Brazil Nagib M. A. Nassar • Dalva G. Ribeiro • Nayra N. Bomfim • Pollyanna T. C. Gomes Received: 11 May 2010 / Accepted: 13 September 2010 / Published online: 17 October 2010 Ó Springer Science+Business Media B.V. 2010 Abstract A new species of Manihot has been collected from Fortaleza, Ceará state, Brazil. It was grown at the living collection in the experimental station, University of Brasilia since 1980 and left for natural reproduction. It bred true during all these years giving rise to identical typical plants of the ancestor one. The closest species to it is M. glaziovii. Apparently this new species was formed by sporadic hybridization between M. glaziovii and cassava itself in its natural habitat, Ceará. It possesses morphological marker gene of the latter one which is ribbed fruit that is found only in cassava. Interspecific hybrids produced experimentally between M. glaziovii and cassava showed similar morphological markers. Exam of its ovules revealed formation of multiple embryos, an indicator of apomixis. Grafting it with common cassava was compatible, giving increased root size up to seven times. Keywords Apomixis Caatinga vegetation Grafting Interspecific hybridization Manihot glaziovii Multiembryonic ovule N. M. A. Nassar (&) D. G. Ribeiro N. N. Bomfim P. T. C. Gomes Universidade de Brası́lia, Brası́lia, Brazil e-mail: [email protected] Introduction The genus Manihot was initially authored by Adanson (1763). Miller in the fourth edition of the Gardner Gardner0 s dictionary in 1974, provided the first valid post-Linean description of the genus Manihot (Rogers and Appan 1973). Pohl (1827) in Plantarum Brasiliae Icones et Discriptions provided the first monograph study of the genus Manihot. Miller and Webster (1962) revised it focusing on its ressemblance with the genus Cnidoscolus because both have a single floral envelope, and share a base chromosome number (x = 9). The last full monographic description was presented in 1973 by Rogers and Appan. They established 98 species, and separated from it Manihotoides giving it status of a second genus. Nassar added in 1986 the species M. neusana (Nassar 1986). Wild Manihot species are precursors of cassava, an important food staple crop for more than 800 million people in tropics and subtropics. They have received attention from research institutions in the decade 1970s as a source of useful genes for improving the crop. It is aspirated that this may contribute to increase world production of food and eradicate hunger in poor countries. For this reason, an extensive living collected was grown and maintained at the University of Brasilia, with the help of IDRC, since the decade 1970s up to this date (Nassar 1978a, 1999, 2003). One of these grown introductions is the subject of this article. Its seeds were collected in 1976 from 123 832 plants growing on the road between Fortaleza and Itapipoca, Km 32, in the State of Ceará, Northeast of Brazil. The referred seeds were propagated at Experimental Station of Biology at University of Brasilia. These plants were examined morphologically, anatomically and embriologically. Stalks of both Manihot glaziovii and the new introduction were grafted to cassava stalks, and then planted in October 2006. Latin diagnosis Manihot fortalezensis a M. glaziovii Muell. habitu gracili, caule 10–15 cm diameter. (versus caule 20–30 cm diameter), folio obovato, 10–12 cm lato (versus folio ovato, 10 cm lato), lobo mediano 15 cm longo (versus 25 cm longo), fructu coerulescenti (versus virescenti), leviter costato (versus fructu haud costato), sacco embryonali singuli embryone munito (versus multis embryonibus munito) abunde differt. Holotype 109906 Herbario UnB, Brasilia Brasil, Ceará, 32 km from Fortaleza to Itapipoca, collected by N. Nassar. Description of the new species; Manihot fortalezensis Nassar, Ribeiro, Bomfim et Gomes Shrub ca 4 m high. Trunk at the base 10–15 cm in diameter. Stem slender weak, branches by 3 m height. Young and mature stems glabrous. Leaves alternate, stipules caduceous, petioles ca 35–40 cm long, glabrous. Petiole attachment to lamina slightly peltate, width between basal edge of lamina and petiole junction 0.5–1.0 cm. Leaves coriaceous. Abaxial surface white greenish. Venation camptodromous, veins glabrous, palmately 5 lobed. Lobes obovate with acute apex. Median lobes ca 15 cm long, 12 cm width. Apex extremely acute never broad. Base of lobes 3–3.5 cm wide. Lamina at sinus never overlapping. Inflorescence monoecious, terminal, branched ca 20 cm long, glabrous reddish bloom. Pistillate flowers restricted to upper of the inflorescence. Pedicels ca 0.1 cm long. Flower tepal 1.5 cm long, reddish. 123 Genet Resour Crop Evol (2011) 58:831–835 Bracteoles setaceous ca 0.5 cm long. Margin slightly pendulate. Disk prominent reddish, ovario subglobose. Staminate buds obvoid, flower tepal 1 cm long. Disk prominent reddish. Stamens 10 into whorls 5 each. Capsules 2.5 cm diameter slightly winged. Seed 1–1/2 cm long caruncule prominent. Anatomical sections of primary root showed presence of sub epidermal layer. Exame of ovules revealed presence of multiembryonic sacs in about 28% of ovules (Fig. 1). Holotype 109906 Herbario UnB, Brasilia Brasil, Ceará, 32 km from Fortaleza to Itapipoca, collected by N. Nassar. Results and discussion Screening results The collected seeds were propagated every year since 1977 giving further generations. The offspring bred true without segregation during the whole subsequent 30 years. This triggered our attention to examine it for apomixis. Results of investigation were positive, and more than 28% of examined ovules showed polyembryonic confirming apomictic nature (Fig. 1). Apparently apomixis is responsible to perpetuate this type and evolving this new species in its natural habitat. It seems that apomixis has played Fig. 1 Manihot fortalezensis. Multiembryonic sac Genet Resour Crop Evol (2011) 58:831–835 833 Fig. 2 a Stem of M. fortalezensis, b M. glaziovii, c M. esculenta Fig. 3 At left, leaf of M. esculenta. In the middle, leaf of M. fortalezensis. At right, leaf of M. glaziovii Fig. 4 At left, fruit of cassava. In the middle, fruit of Manihot fortalezensis. At right, fruit of M. glaziovii an important role in evolution of species of this genus. Nassar (1985) has reported the new species Manihot neusana which showed later to be highly apomictic. In the decade 2000 the same author (Nassar 2006) reported evolving of new species by chromosome doubling accompanied by apomixis. Grafting stalks of the new material native to Fortaleza with cassava was compatible far more than grafts made between cassava and original Manihot glaziovii Muell. It was success in 100% out of 200 grafts, while in case of original M. glaziovii Muell. percent of success was 30% within the same number of grafts made. Successful grafts of the new material grew vigorously too. This new approach of examining relationship between species by grafting proved successful. In addition, it showed very much promising for improving cassava production nationally 123 834 Genet Resour Crop Evol (2011) 58:831–835 since it enlarged root size up to sevenfolds. We designed a project to introduce it to small farmers to enable them adopt technique of grafting and use it in their properties. Grafting it with cassava was highly compatible, giving enlarged roots up to seven fold. When propagated by cuttings it germinates easily contrary to M. glaziovii Muell. Interspecific hybrids between cassava and M. glaziovii were produced experimentally and compared morphologically with this new material. It was highly similar, having stem slender 3–3.5 cm diameter (Fig. 2), median lobe 15 cm long, obovate 10–12 cm width (Fig. 3), fruit exhibited the morphological marker of ribbed fruit (Fig. 4). The features found in M. fortalezensis are intermediate between M. glaziovii and M. esculenta, as noted in the Table 1. Therefore the new material collected from Fortaleza, Ceará is defined as a new species and called Manihot fortalezensis Nassar. Ecology and distribution The region where the seeds of Manihot fortalezensis Nassar were collected is characteristic of caatinga vegetation composed principally from dry scrubs, latitude 4.8, occurring along road side. It flourishes in limestones soil and in dry vegetation. Morphological relationships The new species, M. fortalezensis Nassar, is distinguished from M. esculenta Nassar and its closest relative M. glaziovii Muell. according to the table below. Position in section Glaziovianae The modified Key to the species of sect. Glaziovianae according to Manihot sect. Glaziovianae Pax emend. Rogers and Appan is as follows: 1. Inflorescence a panicle. 2. Bracts and bracteoles setaceous, less than 0,25 cm wide. 3. Petiole attachment peltate. 4. Inflorescence usually more than 10.0 cm long, many flowered. 5. Leaves usually 3 lobed; median lobes obovate, usually more than 3.0 cm wide less than 7.0 cm; lobes usually overlapping at the sinus; basal lobes recurved M. glaziovii Muell.- Arg. 5. Leaves usually 5 lobed; median lobes very obovate with acute apex, more than 10.0 cm; lobes not overlapping at the sinus; basal lobes, basal lobes curved up. M. fortalezensis Nassar 4. Inflorescence less than 10.0 cm long, few flowered; leaves 5 lobed; median lobes oblong usually less than 3.0 cm wide; lobes separated at sinus; basal lobes straight. M. pseudoglaziovii Pax et K. Hoffmann 3. Petiole attachment basal. 6. Inflorescence totally glabrous (with the rare exception of the interior surface of tepal) M. epruinosa Pax et K. Hoffmann 6. Peduncles, pedicels, bracteoles, bractlets and filaments pubescent. M. brachyandra Pax et K. Hoffmann 2. Bracts and bracteoles foliaceous, more than 0.5 cm wide. M. maracasensis Ule 1. Inflorescence a raceme. 7. Staminate buds ovoid-ellipsoid; leaves usually 3 lobed; lobes never pandurate. M. catingae Ule 7. Staminate buds conical; leaves 5 lobed; lobes frequently pandurate. M.dichotoma Ule 123 Genet Resour Crop Evol (2011) 58:831–835 835 Table 1 Differences between the new species, and its closest relative M. glaziovii Muell. Character M. glaziovii M. esculenta M. fortalezensis Stem Erect 20–30 cm diameter Slender 1–1.5 cm Slender 3–3.5 cm Leaf node Slightly prominent Very prominent Prominent Leaf Width Median lobe 25 cm long Ovate 10 cm width Usually 14–17 cm 2.6–5 cm Median lobe 15 cm Obovate 10–12 cm Fruit hybrid Globose, greenish Embryo sac One sexual embryo Grafting with cassava Weak compatibility Cuttings germinate Very difficult, almost impossible Acknowledgments This work was carried out with the assistance of the Conselho Nacional de Desenvolvimento Cientifico—CNPq, Brasilia, Brazil. The new material and the above-mentioned living collection were established at the University of Brasilia with support from the Canadian International Development Research Centre, Ottawa in the 1970s. Thanks are due to Tarciso filgueiras for latin diagnosis and M. Nayar, and M. Jain for reviewing the manuscript. References Adanson M (1763) Families dês Plantaes II, Partie Paris, p 356 Cruz ND (1967) Nova espécie do gênero Manihot Adans. do Estado de Minas Gerais. Bragantia 26 (n.unico) Gratapaglia DE, Nassar NMA, Dianese JC (1986) Biossistemática de espécies brasileiras do gênero Manihot baseada em padrões de proteı́na da semente. Cienc. Cult. 19:294–300 Miller KI, Webster GI (1962) Systematic position of Cnidoscolus and Jatropha. Brittonia 14:174–180 Nassar NMA (1978a) Conservation of the genetic resouces of cassava (Manihot esculenta): Determination of wild Species localites with emphasis on probable origin. Econ Bot 32:311–320 Bluish, slightly One sexual embryo Multiembryo sac High compatibility Easily germinate Easily germinate Nassar NMA (1978b) Some further species of Manihot with potential value to cassava breeding. Can. J. Pl. Sci. 58:915–916 Nassar NMA (1978c) Wild Manihot species of Central Brazil for cassava breeding. Can. J. Pl. Sci. 58:257–261 Nassar NMA (1985) Manihot neusana Nassar: a new species native to Paraná, Brazil. Can. J. Plant Sci. 65:1097–1100 Nassar NMA (1986) Genetic variation of wild Manihot species native to Brazil and its potential for cassava improvement. Field Crops Res 13:177–184 Nassar NMA (1999) Cassava, Manihot esculenta Crantz genetic resources: their collection, evaluation, and manipulation. Adv Agron 69:179–230 Nassar NMA (2003). Gene flow between cassava, Manihot esculenta and its wild relatives. Gen Mol Res, Riberao Preto 2:334–347 Nassar NMA (2006). The synthesis of a new cassava derived species M. vieiri Nassar. Genet Mol Res, Riberao Preto 5:536–541 Pohl J (1827) Plantarum Brasiliar icones et descriptiones. 1:17–56 Rogers DJ, Appan SG (1973) Manihot manihotoides. Flora Neotropica, NY Storey HH (1938) Virus diseases of East African plants. VII-A eld experiment in the transmission of cassava mosaic. East African Agric J 3:446–449 123