Genetic Diversity of Some Saudi Barley (Hordeum Vulgare L.) Landraces Based on Two Types of Molecular Markers

Problem statement: Very little is known about the genetic diversity and morphological variability present in barley landrace in KSA, a country experiencing loss of biodiversity because of replacement of landraces with modern landraces.Approach: The molecular markers RAPD and ISSR were used as an efficient tools to estimate the intra-and inter-cultivar polymorphism among six barley KSA landraces collected from different geographical regions in order to assess the genetic relationships and develop cultivar-specific molecular fingerprints.The long term objective was to use these fingerprints to identify molecular markers that co-segregate and could be used in isolating gene(s) which controlling some important traits, thereafter could be used in breeding programs (marker assisted selection).Results: Out of 20 and 10 primers of RAPD and ISSR, respectively, a clear and reproducible band profile of 13 RAPD primers and 7 ISSR primers were obtained.In RAPD analyses, 61 out of 111 bands (54.6%) were polymorphic.The number of alleles ranged from 5-15 per primer, with an average of 8.54 per primer.In ISSR analyses, a total of 53 alleles were detected, among which 16 alleles (30.2%) were polymorphic.The number of alleles per primer ranged from 5-10 with an average of 7.57 alleles per ISSR primer.The mean Polymorphism Information Content (PIC) values were 0.45 and 0.37 for RAPD and ISSR markers, respectively.Conclusion: ISSR is better than RAPD to detect genetic diversity among the barley landraces.The RAPD's and ISSR's have confirmed each other and the ISSR results are more realistic comparing to RAPD results regarding to the geographical distribution of the six barley landraces.The outcome of this investigation can help strengthen the exiting pool of information on barley that may help assess national barley programs in KSA.