Sources and inheritance of resistance to leaf curl virus in Lycopersicon.

One hundred and twenty-two varieties, lines and wild accessions of Lycopersicon were screened under three different regimes during the autumn/winter season of 1982-83 and 1983-84 for resistance to tomato leaf curl virus (TLCV). L. hirsutum f. glabratum ('B6013') and L. hirsutum f. typicum ('A1904') proved to be highly resistant to TLCV in all three environments. Various accessions of L. peruvianum were also highly resistant. L. pimpinellifolium ('A1921') exhibited no TLCV symptoms within 90 days. Of the cultivated varieties, 'Acc 99' exhibited the minimim score for susceptibility; 'AC 142', 'Collection No. 2', 'Kalyanpur Angurlata' and 'HS 101' had a low rating for virus incidence. The inheritance of resistance was studied in the interspecific crosses between a TLCV resistant line of L. pimpinellifolium ('A1921') and five ('HS 101', 'HS 102', 'HS 110', 'Pusa Ruby' and 'Punjab Chhuhara') susceptible cultivars of L. esculentum. Parents, F1, F2 and backcross progenies were artificially inoculated with local strains of TLCV using vector the viruliferious whitefly, Bemisia tabaci (Genn.). Data indicated that the resistance of L. pimpinellifolium ('A 1921') is monogenic and incompletely dominant over susceptibility.