Comparative analysis of changes in leaf area index in different wheat genotypes exposed to high temperature stress by late sown condition

Abstract

High temperature stress during grain-filling period is one of the major environmental constraints limiting the grain yield of wheat in India. Crop growth response and relative performance of yield components of 12 wheat (Triticum aestivum) genotypes were studied in two date of sowing in crop research center (Pantnagar) to identify the causes of yield reduction in wheat particularly Leaf Area Index and its impact in yield loss and other tolerance mech-anism and comparative study of LAI and yield attributes to identify the genotype for high temperature tolerance in late sown condition. The higher temperature enhanced plant growth, flowering, and maturation which ultimately effects the crop performance in case of yield (Leaf Area Index, grain weight/spike and test weight were drastically reduced in time under high temperature. Out of 12 diverse genotypes namely HI 1539, DBW 14, HW 5021, HS 240, PBW-574, Raj 4101, Lok 54, Raj 3765, WH 1021, K-0-307, HW 2045 and HI1544,four were (Lok54, Raj3765, HI1539 and HI1544 ) were characterized as high temperature tolerant based on their relative performance in leaf area index, grain yield and heat susceptibility index. Leaf area Index studies in context to heat stress in wheat is least studied area in heat tolerance research in wheat (Triticum aestivum), in the present study LAI is used as a screening tool for heat tolerance and effect of LAI in wheat yield.