Resistance of tomato and sweet-pepper genotypes to Tomato leaf curl Bangalore virus and its vector Bemisia tabaci

Abstract

The primary objective of this study was to identify sources of resistance to Tomato leaf curl Bangalore virus—Bangalore strain 4 (ToLCBV-[Ban4]) and its whitefly vector Bemisia tabaci (Gennadius) in tomato and sweet-pepper genotypes, because resistant cultivars did not exist. A total of 25 wild and cultivated tomato and nine sweet-pepper genotypes obtained from the Asian Vegetable Research and Development Centre, Taiwan and local cultivars were screened at the University of Agricultural Sciences, Bangalore, India, both by whitefly-mediated inoculation of virus in the glasshouse and natural infection in the field. Resistance to virus was assessed by disease incidence, symptom severity and DNA hybridisation tests. Resistance to B. tabaci was measured by counting the number of eggs, nymphs and pupal cases on the tomato genotypes. The wild species Lycopersicon peruvianum INRA sel. and L. chilense LA 1969 were resistant to ToLCBV-[Ban4] but highly susceptible to whiteflies, whereas L. hirsutum LA 1777 was resistant to both the virus and the vector. Among the L. esculentum genotypes, H-24, FL 744-6-9, FL 699 and FL 699 sp + were tolerant to ToLCBV-[Ban4], but were susceptible to whiteflies. Of the nine pepper genotypes inoculated with the virus, only five became infected, at low incidence levels and none were suitable for the development of B. tabaci. Use of tomato lines with resistance to both the virus and the vector offer the best way of controlling these related problems, and the prospects for tomato leaf curl virus disease management in South India are discussed.