This document summarizes the microbial research being conducted at the National Research Centre for Groundnut. Some key findings include: (1) Two strains of Bradirhizobium and three PGPR isolates have been shown to increase groundnut yields; (2) Integrating seed treatments with Trichoderma and other biocontrol agents can effectively manage diseases like stem rot; (3) Isolates of Trichoderma and atoxigenic Aspergillus have potential for controlling aflatoxin contamination. Future research plans include identifying the mechanisms underlying PGPR interactions with groundnut and developing genetically modified PGPR to manage diseases. The document also discusses using groundnut byproducts for microbial fermentation of enzymes and production of

1. National Research Centre
for Groundnut
Status of Microbial
Research
Dr. M S Basu, Ex. Director
Presented in 2006 at NBIAM

2. Theme
 We live on a planet of microbes and
they comprise by far the greatest
amount of biological diversity
 We work to capitalize this strength to
enhance productivity and achieve
sustainability in dryland agriculture

3. Crop Production
 Two strains of Bradirhizobium viz. IGR 6, IGR 40
recommended for Rabi/Summer- capable of increasing yield
by 6-18%
 Two PSB (Bacillus polymyxa and Pseudomonas striata tested
at multilocations under AICRPG and recommended for
Rabi/Summer cultivation
 Three PGPR isolates (all fluorescent pseudomonads) have
been found to increase yield by 7-10% in MLT testing and
recommended for rainfed groundnut
 The PGPR isolates found compatible to seed treating
chemicals like carbandazim

4. Crop Protection
 Integration of seed treatment Trichoderma viride @ 4g/kg +
soil application of castor cake @ 500kg/ha + groundnut
intercropped with pearl millet at 1:3 ratio significantly reduced
the incidence of stem rot
 Integration of seed treatment wit T. harzianum @ 4g/kg and
foliar application of culture filtrate of Verticilluim lecanii (Bio-
control agent) found most effective in management of ELS,
LLS and Rust
 Isolate T 170 of T. harzianum with high and antagonistic
ability against collar rot (A. niger) and stem rot (Sclerotium
rolfsii) was identified and being tested under field condition

5. Crop Quality Aspect
 26 isolates of Trichoderma sp. were tested for their ability to
control A. flavus and some them found promising under in-
vitro
 Atoxigenic isolates of A. flavus identified and being tested
for antagonistic potential to control toxigenic strains of A.
flavus
 300 isolates of Aspergillus sp. were isolated and purified
from soil and pot sample and morphologically characterized
and accessioned in NRCG Repository of Aspergillus
Contd…..

6.  29 new isolates of Trichoderma sp.was purified and
maintained as single spore culture and being tested for their
antagonistic potential under lab condition
 DNA of A. flavus was extracted and characterization of
strains is underway
Contd…..

7. Byproduct Development
 Major constituent of g’nut shell is cellulose (65%).
There is great scope for utilizing it as a substrate
(Carbon source) for microbial fermentation to produce
cellulose enzyme at industrial scale
 Being rich in protein and starch, de-oiled cakes from a
substrate for production of proteases and amylases by
employing proteolytic and amylolytic microorganisms
 From 100 g groundnut shell a total 259 IU of cellulose
could be recovered
 A technology for the production of Oyster mushroom
and milky mushroom from groundnut shell has been
developed

8. Future Strategies (XI Plan)
 Identification of molecular and bio-chemical
basis of signal vis-à-vis interaction of g’nut and
PGPR with special emphasis on bio-control of
soil borne pathogens and genetic enhancement
of PGP traits
 Mining of novel antifungal metabolites and
genes of PGPR for using them in developing
novel fungicides and transgenic in future
 Development of genetically modified PGPR
capable of expressing chitinase & bacillomycin
genes for management of S. rolfsii and
Aspergillus sp.
Contd…..

9.  Studying the PGPR signals to understand
pathogens resistance in plant through
induced systemic resistance (ISR) or
systemic acquired resistance (SAR)
 Identification of effective formulation of
of compatible strains of PGPR, PSM and
Rhizobia and devising effective delivery
system in rain-fed production areas
Contd…..

10. Other Novel Areas of Interest
Bioremediation: Microbe-Plant symbiosis within the
plant rhizosphere into an effective clean up technology
to address heavy metals problem in food and feed
Allelopathic Bacteria: Genetically engineered
allelopahtic rhizobacteria offers diverse opportunity
from crop production/protection to control of weeds
Bacterial Phytohromones: Use of
Methylobacterium strains to stimulate seed
germination, contribute to flavour and reduced
nematode infection using genetically engineered
microbes containing iaaL