Induction of systemic resistance to Colletotrichum falcatum in sugarcane using hairy root extract of Psoralea corylifolia

Eight different treatments using 30 per cent Psoralea corylifolia leaf extract, 10.0 per cent P. corylifolia hairy root extract along with 0.1 per cent carbendazim were screened for their potential to induce systemic resistance in sugarcane against Colletotrichum falcatum under pot culture conditions at Sugarcane Breeding Institute, Coimbatore, India. The activity of key defense enzymes of plants viz., Peroxidase (PO), Polyphenol Oxidase (PPO), Phenylalanine Ammonia Lyase (PAL), Superoxide Dismutase (SOD), Catalase (CAT) and defense related compounds viz., phenols and proteins were estimated inthe leaves of sugarcane. An increased enzyme activity was observed in the pathogen inoculated treatments when compared to uninoculated treatments. The plants treated with 0.1 per cent carbendazim and 10 per cent P. corylifolia hairy root extract inoculated with C. falcatum showed higher level of enzyme induction followed by 30 per cent P. corylifolia leaf extract treated plants when compared to other treatments. Invariably in all the treatments, increased induction of enzymes and protein content was observed on 40th day and later it was decreased on 45th day. Total phenol content was found to increase gradually throughout the experimental period of 45 days after planting in all the treatments except in case of uninoculated control, where decreased phenol content was noticed on 45th day.