GENETIC DIVERSITY AMONG BREAD WHEAT GENOTYPES USING RAPD AND SSR MARKERS

This study was accomplished during 2017-2018 with the aim to determine the genetic diversity among seven Iraqi bread wheat genotypes (Sham-6, AL-Noor, Tamuz-2, Tamuz-3, Abu-Ghraib, Baghdad and Dujlah) using PCR-DNA based nine RAPD and seven SSR markers at the Molecular Laboratory, Department of Biology, Faculty of Science, University of Kufa, Iraq. Among nine RAPDs primers, the primer OPC-09 showed the highest value for number of polymorphic bands, polymorphism, efficiency and discrimination. The highest numbers of amplified and monomorphic bands were produced by primer OPA-02. The highest number of main and unique bands was produced by primer OPB-07. Phylogenetic relationship constructed using RAPD markers grouped all the wheat genotypes in one large cluster except the genotype Dujlah. Higher genetic distance (0.3356) was observed between wheat genotypes Tamuz-2 and Dujlah while the lowest genetic distance (0.077) was recorded between wheat cultivars AL-Noor and Baghdad. Among seven SSR markers, analysis revealed that primer Xgw-m162 was more efficient by producing the highest values for allele number, gene diversity and polymorphic information content (PIC). Highest values for major allele frequency were produced by primers Wmc6037A, Xgwm608, and Xgwm6395B. Primers Wmc596, Xgwm1202B, and Xgwm2641B produced the highest values for heterozygosity. Highest value of PIC was produced by primer Xgw-m162 confirming its importance and found highly informative in studying the genetic diversity among the wheat genotypes. Dendrogram of phylogenetic relationship using SSR markers revealed that all the wheat genotypes were grouped in one large cluster except cultivar Tamuz-2. In future, such type of studies will serve as baseline for plant breeders to select appropriate parental genotypes to obtain highest desirable heterosis in wheat populations during hybridization.