Estimation of genetic diversity utilizing gene-targeted SCoT markers and morpho-chemotypic analyses in Senna alexandrina Mill. (Senna)

Abstract

Senna, an industrial crop that generates foreign exchange, is planted predominantly in southern India. Senna leaves and pods grown in India are valued in international trade and the global market because they contain a high concentration of the chemical component sennosides. The current investigation was conducted in the CSIR-CIMAP experimental farm in Hyderabad, India. The experiment was designed in an RCBD and replicated three times using twenty-five senna accessions in the years 2020–21 and 2021–22. The combined ANOVA found that all fourteen of the traits studied were highly significant. The D2 analysis and λ1-λ2 values classified the 25 accessions into five clusters with 91.05 % diversity. The molecular diversity was also examined using SCoT markers. As SCoT markers target expressed portions of the genome, the variation among accessions reflects some of the morphological changes among them. For pharmaceutical applications, various lines Gen-1 and 2 (high in Sennosides A and B content) and Gen-4 can be hybridized with Gen-5 and 25 to produce generations high in pharmaceutically relevant Sennosides A and B. Considering genotypes Gen 1 and 2 rank first and second in terms of sennoside A and B contents in leaves (%) and pods, these two genotypes can be employed for large-scale cultivation and to transfer favorable traits in future breeding programs.