Screening of tomato genotypes for vegetative and reproductive characters under low temperature regime

Abstract

Twenty five tomato genotypes were screened for low temperature tolerance under open field conditions during 2012-13 and further selected tolerant and susceptible genotypes were screened under control conditions (phytotron) for confirmation. When grown under field conditions during winter, the membrane stability index was highest (83.27%) in Pusa Sadabahar followed by Pusa Sheetal (81.17%), whereas, it was least in line H-88 (29.67%). The highest number of flowers per truss was observed in the wild species Solanum pimpinellifolium and S. peruvianum and these lines also had viable pollens, but the number of fruits per truss was negligible in the S. peruvianum lines. The cultivar Pusa Sadabahar recorded the highest number of fruits per truss followed by 120-1. Solanum pimpinellifolium and S. peruvianum lines, S-699 and DTR-2 showed considerably high shoot dry weight. The physiological parameters like membrane stability index, relative water content, tolerance index and shoot dry weight were reduced in all the genotypes under phytotron in response to low temperature (15/8 and 16/10°C) as compared to plants grown under optimum conditions (26/22°C). Pusa Sadabahar, Pusa Sheetal and DTR-2 showed tolerance to low temperature (15/8 and 16/10°C) with respect to the vegetative characters studied.