285-293A total of 22 accessions of 3 Morinda
spp. (Family: Rubiaceae), namely, M.
citrifolia, M. tinctoria and M.
pubescens were collected from three geographical locations of India, viz., Andaman and Nicobar
Islands, Tamil Nadu and Karnataka. RAPD (52) and ISSR (60) primers
were employed as genetic marker to study the genotypic variation within and
between Morinda spp. In RAPD, only 26
primers amplified and gave reproducible fragments, of which 11 primers were polymorphic.
Among 1767 amplified DNA fragments obtained, 953 (54.33%) were polymorphic. The
accessions AHD and SHE-1 were the most closely related cultivars with the
highest similarity index (0.943) and BBD and MAA-1 were the most distantly
related cultivar with lowest similarity index (0.387). In ISSR, of 60 primers
tested, 22 gave clear and reproducible fragments. In total, 1892 fragments of different
lengths were amplified, of which 1052 bands (56.02%) were polymorphic.
According to ISSR results, the two most closely related cultivars were MTC and
JGH with the highest similarity index (0.944) and the most distantly related
cultivars were BMN with MEM and BGL-2 with lowest similarity index (0.248).
Polymorphism and similarity index values for both RAPD and ISSR systems showed
that both marker systems are equally effective for diversity analysis in Morinda specie