Assessment of Genetic Diversity by Morphological, Biochemical, and Molecular Markers in Gloriosa superba Ecotypes Collected from Different Agro-Climatic Zones in India

Background: Gloriosa superba L., commonly known as Glory Lily, is a medicinally valuable perennial climber native to tropical and subtropical regions of India. It is known for its rich alkaloid content, including colchicine and colchicoside, which contribute to its therapeutic potential in treating various ailments. Despite its pharmacological significance, genomic research on G. superba remains limited due to the lack of genetic markers, hindering molecular studies and breeding advancements. Methods: This study utilized a previously reported de novo transcriptome assembly of G. superba, identifying 14,672 EST-SSRs as genomic markers to assess genetic variations across different accessions. Genetic diversity was examined using SSR markers, while 20 morphological traits were systematically evaluated across 19 G. superba accessions from diverse geographic regions to provide insights into trait variability. Results: The most highly variable traits included plant height, number of leaves per plant, number of branches per plant, fresh pod yield, fresh seed yield, dry seed yield, number of pods per plant, leaf width, and internodal length, with coefficients of variation (CV) ranging from 63.53% to 22.45%. Intermediate CV values (10.05% to 18.75%) were observed in eight traits, while three traits (days to flowering, days to 50% flowering, and colchicine content) had low variation (<5%). Principal component analysis (PCA) accounted for 51.3% of phenotypic variation, with PC1 and PC2 contributing 29.4% and 21.9%, respectively. Clustering analysis grouped the 19 G. superba accessions into two main clusters and four sub-clusters, highlighting significant genetic divergence, with the highest dissimilarity (81.45%) observed between accessions from Arrupukottai and Pachmarhi. SSR analysis using 112 markers revealed high polymorphism but a relatively low heterozygosity index (H = 0.277) and PIC values of individual SSRs ranged from 0.26069 in RGM-51635 to 0.4534 in RGM-24219. Conclusions: The genetic divergence observed among the collected G. superba ecotypes provides valuable insights for future breeding programs aimed at enhancing cultivation efficiency and developing superior varieties with improved yield and colchicine content.