Genetic diversity revealed by ISSR molecular marker in different species of Ocimum

Genomic DNA assays of different Ocimum species were performed with inter simple sequence repeats primers (ISSR). The genetic diversity among four Ocimum species namely O. basillicum var. basillicum, O. americanum, O. basillicum var. thysiflora, and six different accessions of O. tenuiflorum collected from various region of Maharashtra were studied. Ocimum species are well-known for their medicinal benefits and are commonly used in indigenous system of medicine. The results obtained from ISSR study showed that Ocimum species and O. tenuiflorum accession shows high genetic difference. For this study DNA was isolated using modified CTAB protocol. The collected Ocimum species with some exception shows 100% polymorphism while collected O. tenuiflorum accessions showed genetic diversity that vary from as low 50% to as high as 89%. The collected Ocimum accessions with some exceptions were grouped according to geographical location and also according to altitude at which they grow. The phylogenetic map shows genetic diversity among variety where Jaccard's coefficient varies from 0.22 to 0.80 and it varies from 0.55 to 0.86 among accessions. Jaccard's coefficient was used as the measure of similarity or distance. The results obtained from this study will help in conservation of genetic diversity in Ocimum genotype and also for future crossing of Ocimum for their high yielding marker compound. This project also revealed the suitability of ISSR-PCR for assessing genetic relationship among Ocimum genotype.

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