Evaluation of Heat Stress Indices in Bread Wheat Genotypes
Subject Areas : Journal of Plant EcophysiologyH. Sooghi 1 , N. Babaeian 2 , Gh. Ranjbar 3 , M.H. Pahlevani 4
1 - گروه ااصلاح نباتات و بیوتکنولوژی، دانشگاه علوم کشاورزی و منابع طبیعی ساری، ساری، ایران
2 - گروه ااصلاح نباتات و بیوتکنولوژی، دانشگاه علوم کشاورزی و منابع طبیعی ساری، ساری، ایران
3 - گروه ااصلاح نباتات و بیوتکنولوژی، دانشگاه علوم کشاورزی و منابع طبیعی ساری، ساری، ایران
4 - گروه ااصلاح نباتات و بیوتکنولوژی، دانشگاه علوم کشاورزی و منابع طبیعی ساری، ساری، ایران
Keywords: Grain yield, Plant height, thousand kernel weight,
Abstract :
Heat stress is the most important factor that reducing wheat (Triticum aestivum L.) productionin in arid and semi-arid regions.Therefore, selecting heat tolerance cultivar is more neccessary. To evaluate indicators of heat tolerance in wheat, twenty four bread wheat genotypes were planted at two locations; Gorgan and Gonbad Agricultural Research Stations in two planting date (6th December and 6th March ) based on a randomized complete blocks design with three replicaties in 2012-13. To evaluate heat stress on grain yield traits, some indices such as stress sensitivity index (SSI), tolerance (TOL), geometric mean production (GMP), mean production (MP), stress tolerance index (STI), yield stability index (YSI), yield index (YI) and preference index (PI) were used. Results showed that grain yield in late planting date reduced by 39.8% and 34.5% in Gorgan and Gonbad, respectively. Mean grain yield in Gorgan for normal and late planting date were 499.2 and 198.8 gm-2,respectively. These values for Gonbad were 391.4 and 135.0 gm-2, respectively. Regarding to the fact that MP and STI indices are able to identify high yielding genotypes under both normal and stress conditions. in genral, grain yield decreased by 10% for every 1°C increase mean of temperature from 20°C to 26.4°C. According to result of current study, genotype 21 can be recommended as a desired genotype in normal and stress conditions.
