Inducing Resistance in Sesamum Accessions Against Shoot Webber and Capsule Borer, Antigastra catalaunalis Duponchel Through Mutation Breeding

Abstract

Sesame ( Sesamum indicum L.) is one of the ancient oil seed crops cultivat- ed extensively in several countries of Asia and Africa. Incidence of insect pests and diseases cause severe yield losses in sesame. Among the insect pests, shoot webber, and capsule borer, Antigastra catalaunalis Duponchel (Pyraustidae: Lepidoptera) is predominant throughout India. To identify insect tolerant sesame, 140 sesame accessions were evaluated under glass- house and field conditions for resistance against A. catalaunalis at the Fac- ulty of Agriculture, Annamalai University during 2005–2007. Among the 140 accessions, 14 accessions were found resistant to A. catalaunalis. Based on this earlier work and reports from other sources, in the present work, accessions namely IVTS-2001–7(TKG-22), NIC-7875, NIC-16278, NIC- 17345, NIC-7908, KMR-102, KMR-63, KMR-56, TMV-3 and SVPRI-1 were selected for inducing mutation. These accessions were evaluated for the LD50 with regard to the physical mutagen namely Gamma rays and chemical mutagens namely EMS (Ethyl methane sulfonate) and DES (Di ethyl sulfate). For gamma rays, the LD50 was at 50 krad while EMS and DES registered 0.06 and 0.5 % respectively as LD50. Upon evaluating the first mutant (M1) and second mutant (M2) generations under screenhouse conditions, based on leaf, flower, and capsule damage, mutants of four ac- cessions namely IVTS 2001-7, NIC-7875, NIC-16278, and TMV-3 were rated resistant. To ascertain the segregation of such desirable traits in the mutant generations, concerted field evaluation needs to be conducted till stabilization of phenotypic variability in the offsprings.