Molecular screening of tomato (Solanum lycopersicum L.) genotypes for resistance alleles against important biotic stresses

Abstract

Molecular markers are vastly used as tool for screening of disease resistant/tolerant plant genotypes in early stage of growth in an environment-independent manner. In tomato (Solanum lycopersicum L.), the major biotic stresses like tomato yellow leaf curl virus, Fusarium wilt, tomato spotted wilt virus and root knot nematode cause severe crop loss. Recently, DNA based molecular markers for the screening of resistance alleles for the abovementioned diseases have been reported in tomato. In the present study, a total of eighteen tomato genotypes have been screened for the presence of possible resistance alleles, using sequence characterized amplified region(SCAR) molecular markers. Resistance allele-specific bands for Fusarium wilt disease, tomato spotted wilt disease and partial resistance allele-specifc band for root knot disease have been identified in some of the genotypes used in the present study. However, none of the genotypes was found to contain Ty3 resistance allele-specific band for resistance to tomato yellow leaf curl disease. Thus, possible resistance sources have been identified for three out of the four biotic stresses, mentioned earlier. Thus, the present study has screened the 18 tomato genotypes at molecular level for presence of resistance alleles for biotic stress, which might be further evaluated and explored in future tomato breeding programmes, targeting biotic stress resistance in tomato. At the same time, the study documents the applicability of molecular markers for rapid disease screening in tomato in an environment independent manner.