Selection of tomato (Solanum lycopersicum) genotypes for heat stress and analyzing stability in their physio-morphological traits under different seasons

A field experiment was conducted at ICAR-Indian Institute of Vegetable Research (IIVR), Varanasi, to study the stability in morphological traits of 23 tomato (Solanum lycopersicum L.) genotypes for heat stress during 20072009. Observations were recorded on low (6.0°C) and high temperature (42.9°C) for vegetative characters of plants, e.g. plant height, number of primary branches, days of 50% flowering, number of flowers/cluster, number of fruit set/plant, average fruit weight, fruit length and fruit width. The number of fruits decreased during summer and increased during winter seasons. It was possible by low fertility and pollen viability due to high temperature. In response of stability the genotypes, IIHR-2202 (plant height, number of branches), CH-155 (50% flowering, number of flowers/cluster, number of fruits set), FLA-7421 and Sel-7 (number of fruit set), and EC-538156 (fruit length and width) gave significant value of βi=<1.00, indicating the suitability for high reproducible environment. These genotypes can be utilized for further breeding programme against high temperature.