A rapid field screening method for evaluation of resistance to leaffolder, Cnaphalocrocis medinalis Guenee in rice

Abstract

Rice leaffolder, Cnaphalocrocis medinalis (Guenee) is one of the major foliage feeding insects found in Asia and all the important rice growing regions in India. Identification of resistant sources plays a major role in the eco-friendly management of leaffolders, for which continuous screening of various germplasm lines and breeding material is essential. In the present study, a rapid field screening method was developed for evaluating large number of rice germplasm lines. It involves release of third instar larva on to the rice plants at 30-45 days after transplanting, allowing it to feed for 48 hrs and assessment of damaged leaf area by ImageJ program. It helps in reliable and faster identification of resistant sources. The method is also useful in precise phenotyping of mapping populations in breeding programs for the development of leaffolder resistant varieties