SCREENING OF FCV TOBACCO GERMPLASM ( N. TABACCUM ) FOR REACTION TO TMV INFECTION AND IDENTIFICATION OF RESISTANT DONORS

Abstract

Tobacco mosaic virus is one of the major virus diseases of Tobacco in Karnataka state. It causes severe to moderate yield losses depending on the stage of infection and early infection causes higher reduction in yield and quality. Incidence of TMV is increasing every year due to monoculture of susceptible varieties and also due its wide host range. Development and deployment of resistant cultivars is the most effective and sustainable approaches as chemical measures are ineffective in containing TMV. Identification of suitable resistance donor in FCV tobacco (N. tobaccum L.) is essential to hasten the speed of variety development without linkage drag. 272 germplasm accessions were artificially screened for their reaction to TMV infection. Twenty two lines were identified as resistant to TMV based on hypersensitive reaction. Among these 22, thirteen were the advanced breeding lines and were evaluated for their yield potential. Based on their yield performance and desirable plant type, three lines viz., FCJ 34, FCJ 35 and FCJ 37 were identified as suitable donors for Karnataka Light Soil (KLS) region. Of these three donors, FCJ 34 was found to be homozygous for the N locus and thus stable TMV resistant source for breeding TMV resistant cultivar.