Screening for drought tolerance using molecular markers and phenotypic diversity in durum wheat Genotypes

Wheat is one of the most important staple food crops in the world is adversely affected by drought. Understanding its genetics and genome organization using molecular markers is of great value for plant breeding purposes. The aim of the present study was to assess in formativeness and efficiency of 26 different molecular markers for genetic diversity among 40 durum wheat comprising landraces, old, moderate and improved durum wheat. Phenotypic diversity was evaluated by six traits (yield and its components and time to heading. Significant variation was noted for all parameters. Analysis of principal components contributes determine 74% of the diversity. Cluster analysis was performed to construct dendrogram using Unweighted Pair Group Method with Arithmetic Mean "UPGMA" based on Euclidean distance of genotypes. Five groups were revealed; landraces and old varieties were found to have a characteristic feature of high plant height, moderate yielding and thousand grain weight and reduced days to heading. This indicated that landraces were relatively earlier and relatively taller than the improved varieties. High levels of polymorphism were recorded for SSR markers used in this study. A total of 136 fragments were obtained from the 26 SSR primers and all the bands were polymorphic across all the genotypes screened, most of them were polymorphic. The polymorphism information content (PIC) values ranged from 38 % to 94%, with an average of 74%. These findings provide basis for future efficient use of these molecular markers in the genetic analysis of durum wheat and new strategies could be developed to safeguard and improve our germoplasm for drought tolerance. © IDOSI Publications, 2012.