Correlation between physiological and yield attributes in bread wheat genotypes for high temperature tolerance

Abstract

Aim: The aim of the present study was to observe the role of heat stress in the correlation of physiological and yield attributes in bread wheat genotypes. Methodology: Seven wheat genotypes (PBW781, RWP-2018-30, PBW821, RWP-2018-31, WH1239, RWP-2018-26, and RWP-2018-32) along with three check varities namely DBW14, WH730, and RAJ3765 were grown under timely sown (TS) and late sown (LS) conditions in the field research area of Wheat Section, CCS HAU, Hisar (2018-19). For generating heat stress, delay in sowing (4 weeks) was done in late sown from timely sown. These wheat lines were assessed for several physiological and yield attributes under both conditions and one genotype was found to be heat-tolerant under late sown condition. Results: PBW821 was classified as thermo-tolerant due to maximum grain yield, higher normalized difference vegetation index, photosynthetic rate, chlorophyll content, and lower canopy temperature compared to other varieties under late sown conditions. Interpretation: Identification of a heat-resistant wheat genotype would be a valuable resource for developing high-yielding cultivars under high-temperature conditions, and these findings might also be used in breeding programs. Key words: Grain yield, Heat tolerance, Physiological traits, Triticum aestivum