Genetic diversity of Myanmar rice cultivars detected by DNA markers

Abstract

Genetic diversity of Myanmar cultivated rice accessions was evaluated by DNA markers. The materials included 110 accessions from six different regions of Myanmar and 17 accessions from other countries. Twelve RFLP markers, 6 STS markers and 28 CAPS markers were used. An UPGMA dendrogram was constructed to infer the phylogenetic relationships of the materials. The stability of the nodes in the tree was tested by the bootstrap analysis. All accessions except two could be distinguished from each other by at least one DNA marker. The dendrogram revealed 2 well-distinguished groups, namely, Group I and II. Group I corresponded Japonica. It was further divided into two subgroups Ia and Ib. The subgroup Ia contained Japanese Japonica accessions and all the accessions in the subgroup Ib were Myanmar accessions clearly differentiated from the subgroup Ia. Indica accessions were contained in Group II. It comprised small clusters. Bootstrap analysis was performed to determine the confidence levels of the forks in the dendrogram. In the resulting consensus tree, only 6 forks had bootstrap values above 80%. The grouping of the UPGMA tree and the majority-rule consensus tree were comparable in the subgroups Ia, Ib and IIe. However, the Indica subgroups, IIa, IIb, IIc and IId were not significantly differentiated.