Salt tolerance in barley originating from harsh environment of North Africa

Abstract

Soil salinity is a major abiotic stress in worldwide agriculture. This has incited a quest towards with an aim of improving the crop plants. An insight into the diversity of barley landraces for salinity tolerance will facilitate their use in genetic improvement and breeding programs. Three gene pools representative of Hordeum vulgare L. grown in the North African region and collected from Tunisia, Algeria and Egypt were evaluated at the reproductive stage under non saline and two saline conditions (0, 100 and 200 mM NaCl). A total of 26 agronomic, morphological and yield-related traits were examined by analysis of variance. A significant genetic variation was observed. We successfully identified a set of accessions originating from severe agroclimatic conditions including Tozeur2, Tichedrett, Kerkena and Kebelli2 which remaining the most productive at high salinity having around 4 g grain yield production per plant and about 11 g whole plant dry weight per plant. Cluster analysis and principal component analysis were performed using salt tolerance index (STI), which provided a clear separation of barley landraces. The first three principal components (PC) contributed 64.05% and 66.01% of the variability amongst genotypes at moderate and high salinity level, respectively, with PC1 comprising yield-related traits. Significant number of highly salt tolerant genotypes grouping Early1, Tichedrett, Azrir and Giza125 from North African harsh environment was identified. Data indicate that specific barley genotypes showing differential responses against salinity could be useful as potential germplasm sources for comparative genomic studies and future breeding programs.