Genetic diversity analysis in Cymbopogon species using DNA markers

Genetic diversity of 25 accessions of Cymbopogon aromatic grasses including eight species, two hybrids and one mutant strain were analyzed using DNA markers generated by employing 20 primer pairs derived from cDNAs containing simple sequence repeat (SSR) of rice genome. A total of 151 bands were produced ranging from 3 to 12 per primer pair. The polymorphic information content values varied from 0.143 to 0.916 with an average 0.715. Jaccard’s similarity coefficient ranged from 64 to 87% among the paired accessions. The level of diversity among different taxa/accessions observed during the present study was, however, low relative to the diversity level obtained due to RAPD markers in earlier studies. The pattern of genetic diversity neither matched with the known taxonomic classification, nor did it always match with the distribution of chemical constituents of the essential oils available in these accessions. Thus, present investigation though revealed poor correlation between the molecular and chemical diversity, indicating that chemical diversity in medicinal and aromatic species is not only result of genetic variability, but it also depends on a number of other factors. Thus this study may prove useful in several ways in Cymbopogon conservation and breeding programs and in the development of perfect markers though association mapping for genes involved in controlling agronomically important traits.