Genetic Characterizations Among Drought Tolerant Wheat Genotypes by Biochemicaland Molecular Markers

摘要

Wheat (Triticum aestivum L.) is the world’s most important cereal crop and due to its different uses and nutritive value it is the staple food for more than one third of the world’s population. Wheat production can be enchanced through the development of improved cultivars with wider genetic base capable of producing better yield under various agroclimatic conditions and stresses. This study aims to develop wheat genotypes, which have favorable response and tolerant for drought stress through in vitro culture and genetic polymorphism and genetic similarity of wheat genotypes by biochemical (SDS-PAGE) and RAPD-PCR as molecular marker. The genetic diversity of 25 wheat genotypes was estimated using germination characteristic under drought stress using two concentrations (-9 and -12 bar) from polyethylene glycol (PEG) in vitro and molecular analysis. The phenotypic data showed highly differences between genotypes for germination percentage. In addition, genotypes 2, 8, 13, 19, 22, 23 and 25 were more resistant for drought stress. Genetic similarity matrix was generated on the basis of Nei and Li’s coefficients. The coefficients were used to make clusters using unweighted pair group method of arithmetic means (UPGMA) which separated the studied genotypes into three main groups depending on results SDS-PAGE and RAPD-PCR combination. The first group A (similarity range 0.69 to 0.93) contains on genotypes (1, 2, 3, 5, 6, 7, 8, 9, 10, 11, 12 and 13), the second group B (similarity range 0.73 to 0.93) comprised of genotypes (14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 and 25), while group C includes on genotype-4 (similarity range 0.53 to 0.72) which was distantly related to other two groups. The information generated here along with the use of most advanced DNA fingerprinting techniques like RAPD-PCR would be helpful for future genome mapping programs, as well as for the application of intellectual breeder rights in Egypt. In addition, these tools could be used as complementary of traditional methods of identification of phenotypic traits for the control of registered cultivars in the trade market. This will help in collection and cataloguing of the germplasm in the form of a germplasm bank.