Changes in Phenolics and Some Oxidative Enzymes in Fenugreek Leaves Due to Powdery Mildew Infection

Abstract

The contents of total phenols and orthodihydric phenols, specific activities of polyphenol oxidase (PPO), peroxidase (PO) and catalase in leaves of powdery mildew resistant (NLM and HM 350) and susceptible (T 8 and HM 65) genotypes of fenugreek were estimated at 40, 80 and 100 days after sowing (DAS) in inoculated (E1) and natural (E2) environments. The levels of all the biochemical constituents were higher in resistant genotypes than in susceptible ones before the appearance of disease (40 DAS) in both the environments. In response to infection, an increase was observed in contents of all the parameters except catalase activity in all the genotypes. However, at higher disease severity levels of all the biochemical parameters decreased invariably in all the genotypes except activities of PPO and PO which increased further in susceptible genotypes in both the environments. The role of phenolics and oxidative enzymes in determining resistance in fenugreek against powdery mildew disease has been highlighted.