Assessment of Genetic Diversity in Trigonella foenum-graecum Based on Nuclear Ribosomal DNA, Internal Transcribed Spacer and RAPD Analysis

Abstract

Fenugreek (Trigonella foenum-graecum) is receiving global attention due to rare medicinal properties of significance to human health. Gene banks possess scanty germplasm and very little background information regarding its genetic variability that has hampered its improvement. We investigated the extent of variability among 17 Indian varieties of fenugreek using phenotypic and genetic markers. Multilocus genotyping by ten random amplified polymorphic DNA (RAPD) primers detected an average of intraspecific variations amounting to 64.7% polymorphism in banding patterns. Analysis of molecular variance indicated that a greater proportion of total genetic variation exists within population (91%) rather than among populations. Higher values of Nei’s gene diversity (h) and Shannon Information Index (i) and genetic distance analysis validate higher genetic diversity among Indian fenugreek varieties. SNPs at 14 sites of rDNA region revealed further lineages of distinct varieties with main RAPD clusters. The representative sequences of each subgroup and all distinct varieties have been submitted to NCBI database and assigned Gen Accession numbers HM 176640–176649. The measures of relative genetic distances among varieties of fenugreek did not completely correlate with the geographical distances of places of their development. The homogeneous phenotypic markers proved insufficient in exhibiting genetic divergence among fenugreek varieties studied. Eventually, the knowledge of their genetic relationships, DNA bar coding and phylogenies might contribute for the designing of intraspecific crosses between cultivars of this fenugreek collection with potential interest in seed spices breeding programme.