Evaluation of wild rice MAGIC population for resistance against rice leaffolder, Cnaphalocrocis medinalis Guenee

Abstract

Leaffolder, Cnaphalocrocis medinalis (Guenee), is a prominent defoliator that causes significant yield losses in rice during both the rabi and kharif seasons. Screening and identifying resistant lines are important component in the varietal development programmes. An evaluation was carried out with fifty wild rice MAGIC population which comprised of eight introgressed rice lines along with the resistant check, O. glaberrima (Acc. No. CG 14), standard susceptible check TN-1 and local checks TRY-2, TRY-3 for their resistant against leaffolder population. Out of fifty lines tested, eight entries - WRM-2, WRM-6, WRM-17, WRM-52, WRM-70, WRM-86, WRM-121, WRM-125 showed their resistance and thirty five germplasms showed moderate level of resistance to leaffolder damage. The susceptible check TN-1 recorded 8.92% damage and the local checks TRY-2, TRY-3 showing 12.64% and 11.75% damage respectively. Biochemical analysis of selected germplasms revealed that the accessions with high phenol content showed resistance whereas those with increased high total sugar, reducing sugars and total chlorophyll content were more susceptible to leaffolder infestation. The results of the correlation studies showed that the incidence of leaf folders was positively correlated with total sugars, reducing sugar, and total chlorophyll, but negatively correlated with phenol content. These results demonstrate the possibility of biochemical markers and resistant germplasms in the development of rice varieties resistant to leaffolders.