Genetic diversity among elite varieties of the aromatic grasses, Cymbopogon martinii

The elite and popular cultivars of Cymbopogon martinii were examined for genomic and expressed molecular diversity through RAPD, enzyme and SDS-PAGE protein polymorphisms. The allelic score at each locus of the enzymes as well as presence and absence profiling in RAPDs, overall occurrence of band types etc. were subjected to computation of gene diversity, expected heterozygosity, allele number per locus, and similarity matrix. These, in turn, provide inputs to derive primary account of allelic variability, genetic bases of the cultivated germplasm, putative need for gene/trait introgression from the wild or geographically diverse habitat etc. in elite selections. 'PRC1' possessed highest number of unique bands based on RAPD polymorphism. In variety 'IW31245E', diaphorase and glutamate oxaloacetate transaminase isozymes generated two unique bands as dia-III2 and got-II4. 'RRL(B)77' exhibited three unique bands; one produced by esterase as allele est-II1 and two by malic enzyme (me-III1,3). Only one unique band was generated by malic enzyme in variety 'Trishna'. But sofia had three unique bands, two contributed by diaphorase (dia-II3 and dia-II4) and one by glutamate oxaloacetate transaminase (got-II2). SDS-PAGE analysis revealed presence of unique polypeptide fragments (97.7 kDa to 31.6 kDa) in varieties 'IW31245E', 'RRL(B)77', 'Tripta', 'Trishna', 'PRC1' and var. sofia, generated as a diagnostic marker. In general, molecular distinctions associated with var. motia and var. sofia have been clearly noticed in C. martinii.