Genetic diversity in Tamarix aphylla (L.) H. Karst. using CAAT box-derived polymorphism (CBDP) and start codon targeted (SCoT) polymorphism markers

Abstract

Tamarix aphylla (L.) H. Karst. is an evergreen, haloxeric, ecologically and economically important tree species of the Indian Thar desert. Genetic diversity analysis of this tree species is vital as it survives in extreme climatic conditions. In this study, we employed first time two gene-targeted CAAT box-derived polymorphism (CBDP) and start codon-targeted (SCoT) polymorphism markers for the analysis of the genetic diversity in Tamarix aphylla. A total of 47 wild genotypes of T. aphylla from eight populations of the Indian Thar Desert were analyzed using 12 primers, six from each CBDP and SCoT markers. The percent polymorphism was higher for CBDP (94.84%) than for the SCoT (76.57%) markers. The average PIC value for CBDP and SCoT marker was 0.601 and 0.409, respectively. Both CBDP and SCoT markers demonstrated high levels of genetic differentiation, low gene flow, and high fixation index. Using both marker systems, AMOVA revealed the percent molecular variation was higher in the case of within population than among population. The clustering pattern based on UPGMA and PCoA plots clearly showed that the grouping of genotypes is associated with their geographical origin and habitat. However, few genotypes were significantly diverse from their respective population and grouped in separate clusters with the genotypes of other populations. The findings observed in the present study can be further exploited in the breeding and conservation programs of T. aphylla.