Evaluation of bermudagrass [Cynodon (L.) Rich] accessions with different ploidy levels


Abstract: Eastern Mediterranean is considered as a center of diversity of spp. (Bermudagrass). Phylogenetic analysis from diploids to hexaploids can help our understanding underlying mechanism of polyploidization. Inter-primer binding site (iPBS) markers amplify highly polymorphic long terminal repeat retrotransposons. The objectives were to (1) investigate associations between ploidy level and genetic diversity based on iPBS markers and (2) correlate between similarity matrices of iPBS retrotransposon marker and four nuclear molecular marker systems for Cynodon accessions' genetic analyses. The samples included 40 bermudagrass genotypes with ploidy series ranging from diploids to hexaploids. The iPBS fragments were highly similar to the retrotransposons according to the BLAST search. The simple matching-based UPGMA analysis clustered the 44 genotypes into two subclusters with a mean similarity value of 0.57 but failed to produce a clear ploidy-based grouping. The similarity matrix of iPBS markers poorly associated (r < 0.35) with those of the four other nuclear marker systems. However, iPBS markers resulted in a higher discrimination power and PIC (0.78). Although disomic inheritance of simple sequence repeats (SSR) markers strongly indicated segmental allo-tetraploidy in previous studies, the iPBS-based phylogeny hinted that bermudagrass may have independently followed both auto- and allo-polyploidization, involving C. transvaalensis and C. dactylon

Keywords: Inter-primer binding site, iPBS, Cynodon dactylon, , polyploidy

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