Accumulation of Tomato Yellow Leaf Curl Virus DNA in Tolerant and Susceptible Tomato Lines

Abstract

Four tomato lines (M-60, M-54, 1970, and 2950), an F 1 hybrid (TY-20) tolerant to tomato yellow leaf curl virus (TYLCV), and the susceptible cultivars 1651, 1630, 614-1, and 199-2 were compared for accumulation of viral DNA in TYLCV-infected plants. DNA was analyzed by either alkaline transfer or dot spot hybridization using a cloned viral DNA as a probe. Results obtained with either procedure indicated that in all tested lines viral DNA accumulation peaked at 12-15 days after inoculation. At this time, accumulation of viral DNA in the tolerant genotypes was 10-50% lower than in the susceptible ones. Viral DNA then decreased up to 50% in both the tolerant and the susceptible lines, and it remained at that level (.)