Microbial and herbivore induced phytochemical changes in okra against shoot and fruit borer, Earias vittella (Fab.)

Abstract

Microbial and herbivore induced phytochemical changes were studied in okra variety, Arka anamika and hybrid, CoBhH1, against shoot and fruit borer, Earias vittella. Induction was done either by microbial alone (microbial talc-based bioformulation Pseudomonas fluorescens (Pf1), Beauveria bassiana B2 isolate, Pf1+B2 consortia) or by both microbial and herbivore (E. vittella infestation). Herbivore alone infested plants served as infested control and undamaged plants left as absolute control. Biochemical pathways encompassing induced resistance viz., phenols and oxidizing defense enzymes such as peroxidase (PO), phenylalanine ammonia lyase (PAL) and polyphenol oxidase (PPO) were assessed to envisage the development of induced resistance. Accumulation of phenol was high in Pf1+B2 consortia inoculated plants as against absolute control in variety, Arka anamika and hybrid, CoBhH1. Inoculation with both microbial consortia and E. vittella caused 9.8 times increased accumulation of phenolics in Arka Anamika and 8.6 times in CoBhH1. Defense enzymes activity was also significantly higher in Pf1 + B2 consortia treated plants as against absolute control. Further, infestation by E. vittella resulted in the enhancement of accumulation of phenols, induction of PO, PAL and PPO activity. In absolute control, CoBhH1 had higher phenolic accumulation and increased activity of defense enzymes than Arka Anamika. © JBiopest.