Identification of tomato leaf curl virus (ToLCV) resistant genotypes based on disease incidence, scanning electron microscopic and molecular studies

Twelve tomato genotypes, two resistant checks (56-14-7 and 58-11-1-1), two susceptible checks (Punjab Upma and Punjab Chhuhara) and eight advanced lines (11-2-2, 2-20-2, 6-2-3, 4-4-1-1, 7-4-5, 8-3-2, 8-5-2-1 and 1-2-3) were selected for this study. The advanced lines were screened on the basis of disease score. They showed zero per cent infection and were found to be resistant to ToLCV. Stomatal size, frequency and index on adaxial and abaxial phyloplanes were significantly higher in susceptible as compared to the resistant checks and advanced lines. Trichome size and frequency on both phyloplanes were significantly higher in resistant checks and advanced lines as compared to the susceptible checks. SEM studies also exhibited differences in size and number of stomata, trichomes and epidermal thickenings in resistant and susceptible tomato leaves. Molecular studies revealed the presence of virus in susceptible checks whereas, in resistant checks and advanced lines virus was not detected. Zero percentage of disease incidence, smaller and lesser stomata, larger and higher number of trichomes and absence of virus in advanced lines through molecular studies proved that the advanced lines were resistant to ToLCV.