Abstract
Aim:
This study aimed to assess the plant growth promotional ability and
biocontrol efficiency of native pink pigmented facultative methylotrophs
(PPFMs) of chilli for management of chilli anthracnose disease through
induced systemic resistance mechanism under pot culture experiments.
Methodology: The selected native PPFMs were identified by
analysis of 16S rRNA gene sequence. These isolates along with reference
strain (Methylobacterium extorquens AM1) were inoculated to healthy
chilli plants. The pathogen (Colletotrichum capsici) was later
inoculated to these chilli plants, and induced systemic resistance (ISR)
molecules were estimated at different intervals from one day after challenge
inoculation of pathogen (DAI) upto 7 DAI. Influence of PPFM on plant growth
parameters, yield, capsaicin content and PPFMs population load on
phyllosphere and rhizosphere was studied.?? ???????
Results:
The results of 16S rRNA gene sequence analysis revealed selected isolates as Methylobacterium
populi (PPFM6) and Methylobacterium radiotolerans (PPFM170). The
ISR molecules tested were significantly influenced by PPFM isolates. The
peroxidase and phenyl alanine ammonia lyase (PALase) activity increased from
1 DAI to 7 DAI whereas chitinase, polyphenol oxidase (PPO) and phenol
contents increased upto 5 DAI, after which gradual decrease was noticed.
Inoculation of PPFMs to chilli crop significantly improved plant height, dry
matter and chlorophyll content. Significantly lesser disease incidence, more
yield and more capsaicin content was observed with application of M.
populi as compared to control.?
Interpretation: The present study highlights native M.
populi (PPFM6) of chilli as an effective plant growth promoter,
exhibiting significant biocontrol efficiency against C. capsici.
Key words: Anthracnose, Chilli, Facultative methylotrophs,
Induced Systemic Resistance, Methylobacterium
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