DNA polymorphisms and genetic relationship among populations of Acacia leucophloea using RAPD markers

摘要

RAPD (randomly amplified polymorphic DNA) markers were employed to characterize polymorphisms among 5 provenances of Acacia leucophloea and to detect genetic relatedness of the species with 6 other acacias (A.holosericea,A.auriculiformis,A.mangium,A.dealbata,A.ferruginea,and A.nilotica) widely grown in India.Of 194 markers scored for the provenances,29.38％ exhibited polymorphism.Also,326 markers were generated among 7 species of Acacia,accounting for 55.82％ of the poly-morphisms.The fifteen 10-mer primers employed were capable of producing 1-8 polymorphic bands for the provenances,and 6--17 for all seven species of Acacia.The genetic similarity coefficient based on Jaccard's coefficient revealed that provenances Thirumangalam and Dharmapuri were closely related.The dendrogram based on a sequential agglomerative hierarchical non-overlapping (SAHN) clustering analysis grouped 4 provenances of A.leucophloea (Dharapuram,Thirumangalam,Pudukottai and Dharmapuri) into one cluster and the other provenance,Sendurai,into a separate cluster.The genetic similarity matrix for 7 Acacia species showed that A.nilotica and A.dealbata were distantly related,while A.holosericea and A.ferruginea were very closely related.Cluster analysis grouped the species of Acacias into 3 major groups of which A.dealbata alone formed a separate group.The RAPD markers generated 36 provenance-specific markers and 162 species-specific markers that could have strong applications for species identification and tree breeding programs for A.leucophloea and for other Acacia species included in this study.