Evaluation of Spring Wheat Cultivars Based on Drought Resistance Indices

For evaluation of spring wheat cultivars using drought resistance indices¡ two separately experiments were done in split plot basis of Random Complete Block Design with four replications. This research was done with complete irrigation (control) and drought stress that start before and after of booting stage in research farm of Agriculture Faculty¡ University of Tabriz. Basis grain yield in irrigation (Yp) and stress condition (Ys)¡ calculated quantitative resistance indices such as: TOL¡ MP¡ GMP¡ STI¡ ATI¡ SSI¡ YI¡ DI¡ YSI¡ HM and MSTI (K1STI and K2STI). Yield correlation analysis showed that the best resistance indices have positive correlation with grain yield under irrigation and drought stress were MP¡ GMP¡ STI and HM for two experiments. According to this resistance indices and high yield in irrigation and drought stress conditions and with using of 3-Dimensional diagrams¡ Kavir¡ Niknejhad¡ Moghan3¡ Darya and Marvdasht for drought stress after booting stage and Kavir¡ Niknejhad¡ Darya and Moghan3 for drought stress before booting stage were the most tolerant cultivars. Whereas¡ the most sensitive cultivars for drought stress after booting stage were Bahar¡ Sivand¡ Pars and Bam and Bahar and Pishtaz were the most sensitive cultivars for drought stress before booting stage. Diagram of multivariate biplot showed that forenamed cultivars were near to vectors of MP¡ GMP¡ STI and HM indices. So¡ distribution of cultivars in biplot-space showed that genetically variation between cultivars. Cluster analysis confirmed those results.