Production, physiology, and molecular characterization of sorghum (Sorghum bicolor (L.) Moench) genotypes under the interactions of abiotic stresses

Horizontal and vertical improvement of crop production is one of the most important challenges facing the world to overcome global climate change and dwindling of water resources. Four sorghum genotypes were planted under the stressed habitat (Kharga) compared to that of the adequate one (Ashmoun). The number of tillers, shoot heights, grain weight, biological yields, dry weights and relative water contents of the genotypes decreased under the stressed habitat. The biochemical contents of the genotypes varied, noticeably: the stress increased the carotenoids, soluble sugars, total carbohydrates, proline and mineral contents. However, chlorophyll a & b and total protein contents were decreased under stress conditions. To discriminate the four sorghum genotypes SRAP marker was used. A total of 52 amplicons were generated by 8 tested primer pairs, with a size range of 90 bp to 925 bp, of which 44 were polymorphic (83.4 % polymorphism). The SRAP profile yielded 35 unique bands (out of 52); 24 in a positive (M+) and 11 in a negative state (M-). The discriminatory power (DP) value for the SRAP markers ranged from 60 to 100 % with an average primer efficiency value of 13 %. The dendrogram analysis categorized the genotypes into two major clusters. ICSV 25274 and Dorado were found to be genetically similar, whereas ICSV 745 was the most dissimilar one.