Biomolecular characterization of guar (Cyamopsis tetragonoloba) genotypes along with wild species, C. serrata and C. senegalensis

Abstract

Accessibility to a wide inventory of the genetic diversity is desirable for genetic improvement of a crop. Rare availability of wild species which acts as reservoir for a number of important traits makes their biomolecular characterization highly significant. Cyamopsis tetragonoloba (L.) Taub. genotypes were subjected to molecular characterization by employing random amplified polymorphic DNA (54 genotypes) and seed storage protein profile (53 genotypes) along with two wild species, C. serrata Schinz. and C. senegalensis Guill. & Perr. The aim of this study was to analyse the extent of genetic variability, similarity and species identification. A total of 271 bands were amplified using 25 RAPD primers with an average of 10.84 bands per primer, whereas electrophoretic profile of seed storage proteins produced a total of 37 bands having relative mobility values ranging from 0.13 to 1.00, out of which 15 bands were polymorphic. A few DNA and protein bands specific to wild species were identified which showed that these are genetically distinct from C. tetragonoloba genotypes. Among 25 primers employed for the study, 9 produced a total of 12 unique alleles; however, some genotype/species-specific bands were also obtained in protein profiling. Jaccard’s coefficient-based genetic similarity indices ranged from 0.31 to 0.86 with an average of 0.58, indicating the presence of high levels of DNA polymorphism. But for seed storage proteins, similarity indices ranged from 0.70 to 1.00, indicating less protein variability. The dendrogram constructed by the UPGMA mode revealed genetic relationships among different C. tetragonoloba genotypes and among species. This study provides valuable information regarding characterization, identification, management, parental selection and seed purity that can be used in a synergistic way for augmenting the guar improvement programme in India.