Screening tomato (Lycopersicon esculentum) genotypes for buckeye fruit rot (Phytophthora nicotianae) and quality traits of resistant donors

Abstract

A study was conducted during 2000-2001 for screening tomato (Lycopersicon esculentum Mill. nom. cons.) genotypes for buckeye fruit rot [Phytophlhora nicotianae B.de Hann. var parasitica (Dastur) Waterhouse] and quality traits of resistant donors under natural epiphytotic condition. Of the 73 genotypes evaluated, none was found completely free from disease, 7 genotypes ('LO 701', 'EC 113809', 'EC 392693', 'EC 129602', 'EC 129603', 'LO 1003' and 'EC 191538') were rated as moderately resistant and 47 as moderately susceptible. Besides resistance, some of these moderately resistant or moderately susceptible genotypes possessed desirable horticultural traits. Genotype 'EC 129602' gave highest yield (985.70 g/plant), average fruit weight (45 g) and ascorbic acid content (47.5 mg/1OOg) along with minimum (6.15%) level of disease incidence and hence rated as potential genotype for incorporating disease tolerance to evolve new desirable genotypes. Plant height, yield/plant and fruit shape index were negatively correlated with buckeye fruit rot, while fruit size was positively correlated. Ascorbic acid content was significantly and negatively associated with disease incidence (0.239). The possibility of involvement of these genotypes in future breeding programme is discussed.