Discrimination Capacity of RAPD, ISSR and SSR Markers and of their Effectiveness in Establishing Genetic Relationship and Diversity among Egyptian and Saudi Wheat Cultivars

Abstract

Problem statement: Yield crop cultivars and landraces are valuable sources of genetic variations that the knowledge and implication of these variations are critical in the plant breeding programs. our major objective of this study is investigating the discriminating capacity of RAPD, ISSR and SSR markers and of their effectiveness in establishing genetic relationship and diversity among Egyptian and Saudi wheat cultivars. Approach: Eleven wheat cultivars and landraces collected from Egypt and Saudi Arabia, five Egyptian wheat (Sakha 93, Sods 1, Sods 4, Gmiza 9 and Sohag 3) and six Saudi wheat landrace cultivars (Hmees, Al-Kaseem, Hegazi, Abo-Sakr, Dubai 1 and Nagran) were characterized using RAPD, ISSR and SSR molecular markers as efficient tools. Ten and nine oligonucleotide primers of RAPD and ISSR respectively and four primer pairs of SSR were used in wheat samples analysis. Only clear and repeatable band profile of 6 RAPD, 8 ISSR and 2 SSR primers were obtained. In RAPD analyses, 74 out of 141 bands (52%) were polymorphic. Results: The number of alleles ranged from 8-21 per primer, with an average of 14.1 per primer. In ISSR analyses, a total of 78 alleles were detected, along with 36 alleles (46%) were polymorphic. The number of alleles per primer ranged from 5-10 with an average of 8.6 alleles per ISSR primer. SSR reactions recorded 6 alleles, of which 5 alleles (83%) were polymorphic. Cluster analysis was conducted using Unweighted Pair Group Method that depends on Arithmetic Average (UPGMA). The dendrogram cluster diagram classified the evaluated genotypes in three major clusters corresponding to the cultivation regions. The first group contains Sakha 93, Sods 1 and Sods 4 with more than 80% Genetic Similarity (GS). The GS between Sakha 93 and Sods 1, Sakha 93 and Sods 4 or Sods 1 and Sods 4 were 83.6%, 83.9 and 85.4 respectively. The second group contains Gmiza 9 and Sohag 3 with GS 83.1%. The third group contains most of the Saudi landrace cultivars, Hmees, Al-Kaseem, Dubai 1, Abo-Sakr and Nagran, which are genetically closed to each other with GS of 81%. The last Saudi wheat landrace cultivar, Hegazi, was falling outside the three major clusters, revealing around 78% similarity with the rest of the five Saudi landrace cultivars. Conclusion/Recommendations: These analyses fit together with geographical distribution of the 11 wheat cultivars and landraces. Moreover, some morphological characterizations as fresh and dry or flowering time between the selected cultivars were analyzed under different salt concentration. We recognized differences in the fresh and dry weight between the selected cultivars. Wheat cultivars Sods 4 and Sohag 3 were the most sensitive cultivars to the salt treatment, while Sods 1 and Sakha 93 cultivars were less sensitive to the salt treatments. Additionally, Sods 4 and Sakha 93 cultivars were the earliest among the five wheat cultivars (flowering time 68.0±5.04 and 71±6.97 days respectively), while Sohag 3 and Gmiza 9 have flowered later than the other five cultivars (111±12 and 105±11.1) respectively. In conclusion, the long term objective of this study 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.