Physio-genetic approaches for increasing wheat (Triticum aestivum) productivity under rice (Oryza sativa)-wheat cropping system.

摘要

A field experiment was conducted during 2002-2005 in New Delhi, India to identify agronomic traits which could be used for screening large number of wheat (Triticum aestivum) genotypes for heat tolerance under late sown conditions. Data were recorded on membrane injury index, relative water content and rate of photosynthesis under normal and late planting conditions on various stages of ontogeny. Correlation between plant height, grain yield, peduncle length, grains per spike, tiller/m2, spikelet per spike, flag leaf area and spike length with biomass weight was determined under late-sown rainfed and irrigated conditions. Maintenance of low leaf temperature (25/17 degrees C) was an essential trait of heat tolerant genotypes. The low membrane injury index (14.4-25.5%) and high relative water content (86.34) was also essential traits of heat tolerant genotypes. At low leaf temperature, the pace of metabolic activities were relatively high under stress conditions. The close association (0.76) of membrane injury index with percent reduction in biomass clearly indicates that this trait could be used for screening large number of genotypes for heat tolerance under late sown conditions..