Heat tolerance evaluation of wheat (Triticum aestivum L.) genotypes based on some potential heat tolerance indicators

Twenty wheat genotypes including advance lines and cultivated varieties were evaluated for terminal heat stress under glass house conditions in pots using completely randomized design with three replications in 2010-2011. plants were exposed to 35-40 °c temperature 3 hours daily for five consecutive days. control plants were kept under normal temperature conditions. the stress tolerance indicators such as superoxide dismutase (sod),peroxidase (pod),photosynthates stem reserves (psr),membrane stability index (msi) and grain yield revealed significant (p<0.05) effect of high temperature on growth and physiological attributes of wheat at anthesis growth stage. cumulative response of faisalabad-2008,lasani-2008,sussui and aari-2011 was better in terms of proline accumulation,better antioxidant defense mechanism,psr,msi,and grain yield under stress and non- stress conditions. but 4th ebwyt-1,4th ebwyt-2,4th ebwyt-3,and nr-397 were found heat sensitive on the basis of used heat tolerance indicators. in addition to the grain yield plant breeders should also include sod,pod,psr and msi as markers in the breeding program for development of heat tolerant wheat cultivars.