Diversity analysis of released varieties of Indian cardamom using ISSR markers reveal narrowing genetic base

Abstract

<em>Elettaria cardamomum </em>Maton the small cardamom of commerce is a monotypic genus in India under the family Zingiberaceae. Genetic diversity studies using inter simple sequence repeat (ISSR) markers were conducted on a total of 13 released varieties of cardamom including selections and hybrids from different research stations in South India along with a popular variety Njallani and a wild relative <em>Aframomum </em>sps as checks. ISSR markers however, revealed relatively high level of genetic redundancy among the tested varieties with the exception of a few. Nonetheless, unweighted pair group method of arithmetic average (UPGMA) based cluster analysis of the similarity matrix differentiated all the varieties tested with the exception of two and segregated the wild relative <em>Aframomum</em>. Considerable reduction of polymorphism percentage was observed on exclusion of <em>Aframomum </em>while studying ISSR polymorphism which could be an indicator of the narrowing genetic base in the released varieties. Morphological data were compiled based on International Plant Genetic Resources Institute (IPGRI) cardamom descriptor and revealed moderate variability among the varieties. The results highlighted the requirement of molecular characterization of unutilized germplasm accessions, related wild species, and exotic relatives using specific molecular markers to help refine breeding efforts and introgression of new alleles for further improvement and enhancement of genetic base of cultivated cardamom.