Selection of tomato genotypes resistant to tomato leaf curl virus disease using biochemical and physiological markers

Abstract

SUMMARYA total of 34 tomato genotypes (24 F1+10 parents) were tested for resistance to tomato leaf curl virus (ToLCV) disease by various whitefly inoculation techniques under field and insect-proof glasshouse (mass and cage) conditions. Of the ten tomato parental lines, two accessions [EC-520061 (Solanum habrochaites) and EC-521080 (Solanum pimpinellifolium)] were identified as highly resistant while four accessions (EC-520049, EC-528372, WIR-5032 and WIR-3957) of wild species were resistant to ToLCV. Out of the 24 F1 crosses, PBC×EC-520061, H-86×EC-520061, H-24×EC-520061 and DVRT-2×EC-520061 were found to be highly resistant against ToLCV disease. Biochemical (total phenol and total sugar concentration) and physiological (chlorophyll content and leaf area index) parameters were also used in healthy and disease-inoculated leaves of ten parents and six F1 hybrids to test the conformity of ToLCV-resistant and susceptible disease reactions. The results showed that among the 16 genotypes (10 parents+6 F1), EC-520061, EC-520049, PBC×EC-520061 and H-86×EC-520061 were stable for both biochemical and physiological markers while EC-521080 showed higher accumulations of total phenol and sugar concentrations and reduced leaf size between healthy and disease-inoculated leaves. The present study demonstrates the importance of the whitefly inoculation technique and biochemical and physiological markers in virus resistance screening programmes, and identifies a potential source of resistance to the ToLCV in Solanum species.