Assessment of genetic diversity in Azadirachta indica based on DNA fingerprinting

Abstract

RAPD molecular markers were used to evaluate the genetic diversity in populations of Azadirachta indica A. Juss (neem) from different eco-geographical regions of India. Out of the 40 decamer primers used, 24 yielded polymorphic banding patterns. In total, 152 different DNA bands were reproducibly obtained, out of which 104 (68.4%) were polymorphic. The polymorphisms were scored and used in band-sharing analysis to identify genetic relationships. Cluster analysis based on Jaccard’s similarity coefficient using UPGMA grouped all the 36 populations into two major groups. Similarity indices ranged from 0.60 to 0.94. The highest similarity coefficient detected between candidate plus trees from Jodhpur and lowest in the populations of Kalka and Banaswara, indicated that neem germplasm within India constitutes considerably broad genetic base. Also, the neem populations from diverse agroclimatic regions of India were more dispersed on the principal coordinates plot, revealing a wide genetic base.