Download RHIZOSPHERE OF OLIVE TREE: A SOURCE OF PLANT GROWTH

RHIZOSPHERE OF OLIVE TREE: A SOURCE OF PLANT GROWTH
PROMOTING BACTERIA
ALPER DEDE and KIYMET GUVEN
Plant Growth- Promoting Bacteria (PGPB) are associated with many plant species and
commonly present plant microbiota. The most widely studied group of PGPB are plant Growth
Promoting Rhizobacteria (PGPR) which colonizes the root surfaces and the plant rhizosphere.
Countles free-living PGPR such as Pseudomonas, Bacillus, Arthrobacter etc. have used
promote plant growth and control phytopathogens in agricultural fields. The widely recognized
mechanisms of biocontrol mediated by PGPB are competition for an ecological niche or a
substrate, production of inhibitory chemicals, and induction of systemic resistance in host plants
to a broad spectrum of pathogens. Biological control is thus being considered as an alternative
or a supplemental way of reducing the use of chemicals in agriculture.
There has been many studies describing potential uses of plant associated bacteria as agents
stimulating plant growth and managing soil and plant health.
In this study bacteria were isolated from rhizosphere and soil surface of one olive tree and one
olive sapling. The capacity for plant growth promoting activities and antagonistic features were
tested by using siderophore production test, HCN production test, phosphate solubilization test,
indole-3-acetic acid test, amonnium production test, antibacterial and antifungal activity test.
The isolates showing at least 3 out 4 namely phosphate solubilization, indole-3- acetic acid
production, and siderophore productions assumed to be PGPR and they were identified by using
fatty acid methyl ester (FAME) analysis and automated Ribotyping. The bacteria were defined
as Flavimonas oryzihabitans, Pseudomonas putida biotype A Acinetobacter haemolyticus,
Rhizobium radiobacter, Bacillus atrophaeus, Bacillus subtilis, Bacillus megaterium and
Arthrobacter globiformis.
Keywords: PGPR, Antagonistic activity, FAME, Ribotyping