Response of contrasting tomato genotypes under high temperature stress

Abstract

The present study was undertaken to evaluate the response of six contrasting tomato genotypes to high temperature stress. Tomato genotypes were grown under polytunnel to expose them to high temperature (40 ± 2°C) for ten days after flower initiation. Physiological parameters viz., relative water content (RWC), epicuticular wax content, membrane stability index, lipid peroxidation (MDA content) and specific leaf area were recorded in the leaf samples collected second, fifth and ninth day after imposition of high temperature treatment. Membrane stability index decreased significantly in IIHR-2914, IIHR-2627 and Arka Abha genotypes upon temperature stress as compared to other genotypes. Although, there was no significant difference in RWC during early stages of stress, it was significantly higher in IIHR-2841, IIHR-2202 and IIHR-2745 genotypes at ninth day. Epicuticular wax content increased significantly in genotypes IIHR-2202 and IIHR-2841 compared to other genotypes; whereas, lipid peroxidation increased significantly in genotypes Arka Abha and IIHR-2627. Based on these results, genotypes viz., IIHR-2841 and IIHR-2202 were found to be temperature tolerant, while Arka Abha and IIHR-2914 were comparatively sensitive. The genotypes identified as tolerant to high temperature can act as a potential genetic material for future breeding programs to develop high yielding temperature tolerant varieties.