Grouping of Advanced Spring Wheat Genotypes based on Morphological, Physiological and Yield Components under Drought Stress

Drought stress is one of the most important environmental stresses that has limited the production of wheat and has significantly reduced the production efficiency of this plant in arid and semi-arid regions. The aim of this study was to investigate the response of 15 spring wheat genotypes to drought stress and to introduce the best genotypes for cultivation in areas with water shortage.

In order to study of genetic diversity in advanced spring wheat genotypes based on some morphological, physiological and agronomic traits, 15 spring wheat genotypes by using randomized complete block design (RCBD) in three replications under two non-stress and water-deficit stress conditions were examined at research field of Islamic Azad University, Tabriz Branch, Iran during 2016-2017 and 2017-2018 crop years. The morphological, physiological and yield component were assayed.

Based on results of the combined variance analysis, the interaction effects of genotype, irrigation conditions and year were significant for most of the studied traits, except chlorophyll index, carotenoid and chlorophyll b, that indicating the different reactions of genotypes under two non-stress and water-deficit stress conditions. Also, the interaction effects of genotype and water conditions were significant on studied characters except of spike number, spike length and carotenoid. Under water deficit stress the genotypes of URBWYT4, URBWYT1 and ERWYT4 showed the highest seed yield, and URBWYT3, Gonbad, Karim, and Morvarid showed the maximum seed yield in normal condition. Cluster analysis using Ward method based on studied traits with standardized data led to the allocation of genotypes in two separate clusters in both non-stress and water-deficit stress conditions. Also the results of the discrimination function analysis confirmed the genotypes grouping of cluster analysis. According to cluster analysis the genotypes of ERWYT1, URBWYT3, URBWYT5, URBWYT4, ERWYT5, URBWYT1, URBWYT2, ERWYT4 and ERWYT2 in non-stress condition and Morvarid, ERWYT1، ERWYT2، URBWYT2، ERWYT3 and URBWYT4 under water-deficit stress were elite genotypes.

according to obtained results the two genotypes of Morvarid and ERWYT3 can be introduced as the best genotypes for both studied conditions.