Department of Vegetable Crops, Punjab Agricultural University, Ludhiana-141004
National Symposium on “Plant Pathology in the Changing Global Scenario” held at National Bureau of Plant Genetic Resources, New Delhi on February 27–28, 2009
Sixty accessions of tomato comprising of breeding lines from AVRDC, The World Vegetable Centre, Taiwan and promising selections made at Punjab Agricultural University, Ludhiana were evaluated in autumn season (June-December, 2007) against tomato leaf curl virus disease under natural epiphytotic conditions. Disease reaction of each genotype was assigned. Under field conditions out of sixty accessions, twenty five lines were found apparently free from tomato leaf curl virus disease. These twenty five lines along with two local susceptible checks Punjab Upma and Punjab Chuhhara were artificially screened by single plant inoculation technique using viruliferous whiteflies under glass house conditions. Only three lines viz. 58-11-1-1, LCT-8-5 and 115-1-8-1 were found to be free from symptoms. These three lines were further challenged by grafting method of inoculation, using resistant lines as a root stock and leaf curl infested plant as a scion. The resistant reaction of 58-11-1-1, LCT-8-5 and 115-1-8-1 was confirmed because even after 50 days of successful grafting, no viral symptom appeared on all grafted plants of these genotypes. The susceptible checks Punjab Upma and Punjab Chuhhara showed 100 per cent disease incidence in all three assays with in fortnight. The further confirmation of virus resistance was confirmed by PCR using universal degenerate primers.
