Assessment of Relationship for Both Seedling and Maturity Traits with SSR Markers under Drought Conditions in Bread Wheat (Triticum asetivum L.)

Document Type : Original Article

Authors

1 Genetics Department, Faculty of Agriculture, Assiut University, Assiut, Egypt

2 Agronomy Department, Faculty of Agriculture, Assiut University, Assiut, Egypt

Abstract

TWENTY-ONE cultivars of bread wheat were evaluated for drought-stress tolerance atseedling and maturity stages under non-drought and drought-stress conditions. Significant differences among genotypes were obtained under non-drought and drought-stress conditions for all seedling and maturity characteristics. Highly positive and significant correlations were found for root length with respect to fresh weight of 0.74 and dry weight seedling of 0.80. However, negative and highly significant correlations were found for both drought susceptible index based on seedling traits (DSIST) and maturity traits (DSIST) with all seedling traits except root: shoot ratio, whereas no correlations were obtained for either DSIST or DSIMT with all maturity traits except 1000 kernel weight. Positive and highly significant correlation found between DSIST and DSIMT (0.85). SSR markers analysis showed that three bands produced by Xgwm596-7A (507bp), Xgwm497-1A (556bp) and Xgwm174-5D (409bp), they were presented in all tolerant genotypes based on DSIST. The three bands (507, 556 and 409bp) were correlated to DSIST, with R2 values of 81.05%, whereas the three bands were correlated to DSIMT with R2 values of 61.96%. Strong association was observed for genotypic distance with phenotypic distance based on seedling characteristics, that amounted to 0.66, whereas the correlation was less strong between genotypic distance and phenotypic distance based on maturity traits by 0.30. The seedling traits at 15% PEG were more association than maturity traits under drought-stress with SSR markers, this gives preference to using seedling traits as an indicator of drought-stress tolerance in breeding programs.

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