Screening for genetic divergence in tomato genotypes against tomato leaf curl virus

Abstract: During summer 2005 out of 50 genotypes screened for tomato leaf curl virus under field conditions, none of the lines tested were resistant, however, six genotypes showed mild infection and nine genotypes showed moderate infection. In the second season, i.e., 2006 only Nandi and Vybhav showed moderate resistant reaction, along with the new commercial hybrids Hy-558, Hy-530, NS-563 and NS-719. The variety Vybhav was found superior over other varieties against the disease. The presence of virus in the symptomatic hosts was confirmed by ELISA and PCR. The plant height of the genotypes contributes to maximum extent (52.21 %) to the divergence followed by yield per plant and per cent disease incidence (10.86 % each), but the vector population contributed least (0.97 %). As a result of D² clustering, the commercial hybrids possessing lot of diversity fall in to four different clusters, cluster II had got six entries, cluster III 3 entries, cluster IV 6 entries and cluster V only one entry wheras cluster I had 50 entries.