Molecular Diversity Analysis and Metabolic Profiling of Seed Oil in Lepidium sativum L. Genotypes

Assessment of genetic diversity by using metabolic and molecular markers is important for the characterization of local unexplored germplasms of garden cress (Lepidium sativum L.) and their further utilization in crop breeding programme. However, such studies are limited to garden cress, an important medicinal crop of India. In the present study, biochemical, morphological and molecular characters were used to unravel the diversity and relationship among fifteen elite genotypes of garden cress, and the volatile constituents of seed oil were also analysed by GC-MS. Here, we report the genetic differentiation of garden cress genotypes collections in India using 10 RAPD and 9 ISSR markers. Analysis of variance revealed significant mean square values for all the morphological and biochemical traits. Random amplified polymorphic DNA (RAPD) (10) and inter-simple sequence repeats (ISSR) (9) markers produced a total of 114 bands, out of which 89 showed polymorphism. The average polymorphism was 90.8% (RAPD) and 66.03% (ISSR). The mean values of RAPD and ISSR markers for polymorphism information content (PIC) were 0.37 and 0.27, effective multiple ratio (EMR) were 4.92 and 3.10, marker index (MI) were 1.84 and 1.17 and the resolving power (Rp) were 1.39 and 1.56, respectively. In the clustering based on the combined biochemical, morphological and molecular data, the 15 genotypes were divided into two main clusters ranged from 0.50 to 0.86. Based on the observed variations, it is concluded that the magnitude of morphological, biochemical and molecular variations in the garden cress genotypes studied is significant. The volatile constituents of seed oil were also analysed by GC-MS for qualitative analysis which showed 72 similar components in oil of 15 local genotypes of garden cress. The results obtained in the present study could be useful for breeding and improvement of garden cress in the future.