Volume 15, No. 01, Month JANUARY, Year 2022, Pages 34 - 47

Nuclear microsatellites and chloroplast genes revealed strong genetic differentiation between indian (azadirachta indica a. juss.) and thai neem (a. indica a. juss. var. siamensis) varieties

Suchitra Changtragoon, Madhav Pandey, Chanpen Boontong

Abstract Download PDF

Knowledge about, within, and among population genetic diversity is important for an efficient management of genetic resources of a target species. Genetic diversity and differentiation of 17 accessions of Indian neem and seven accessions of Thai neem varieties were investigated covering south Asia, south-east Asia, and Africa by employing eight nuclear microsatellites and three chloroplast genes. Genetic differentiation among seventeen Indian and seven Thai neem accessions measured by AMOVA was 27 % and 25 %, respectively. No significant correlation between pairwise genetic and geographic distances was observed for both varieties. Several unique alleles for Indian and Thai neem varieties were detected. Bayesian cluster analyses grouped the accessions from Thai and Indian neem varieties in separated clusters. To elucidate the phylogenetic relationship between the two neem varieties, we also investigated three genes from chloroplast DNA. Overall genetic diversity was higher in Indian neem than in Thai neem variety. The sequence divergence and the phylogenetic analysis based on three cpDNA (matK, atpB-rbcl, and ycfl-b) genes revealed strong differences between two varieties suggesting that the varieties possibly belong to two different neem species. Implications of the data presented in this study for the conservation and management of genetic resources of neem are discussed.


Azadirachta indica; conservation; cpDNA genes; genetic diversity; genetic differentiation; microsatellites


Published by : The Genetics Society of Thailand
Contributions welcome at :