Evaluation of genetic diversity in turmeric (Curcuma longa L.) using RAPD and ISSR markers

Turmeric (Curcuma longa L) is an industrially important plant used for production of curcumin, oleoresin and essential oil. In the present study we examined the genetic diversity among turmeric accessions from 10 different agro-climatic regions comprising 5 cultivars and 55 accessions. Two DNA-based molecular marker techniques, viz., random amplified polymorphism DNA (RAPD) and inter simple sequence repeat (ISSR) were used to assess the genetic diversity in turmeric genotypes. A total of 17 polymorphic primers (11 RAPDs and 6 ISSRs) were used in this study. RAPD analysis of 60 genotypes yielded 94 fragments of which 75 were polymorphic with an average of 6.83 polymorphic fragments per primer. Number of amplified fragments with RAPD primers ranged from 3 to 13 with the size of amplicons ranging from 230 to 3000 bp in size. The polymorphism ranged from 45 to 100 with an average of 91.4%. The 6 ISSR primers produced 66 bands across 60 genotypes of which 52 were polymorphic with an average of 8.6 polymorphic fragments per primer. The number of amplified bands varied from 1 to 14 with size of amplicons ranging from 200 to 2000 bp. The percentage of polymorphism using ISSR primers ranged from 83 to 100 with an average of 95.4%. Nei's dendrogram for 60 samples using both RAPD and ISSR markers demonstrated an extent of 62% correlation between the genetic similarity and geographical location. The result of Nei's genetic diversity (H) generated from the POP gene analysis shows relatively low genetic diversity in turmeric accessions of South eastern ghat (P7), Western undulating zone (P8) with 0.181 and 0.199 value whereas highest genetic diversity (0.257) has been observed in Western central table land (P9). Knowledge on the genetic diversity of turmeric from different agro-climatic regions can be used to future breeding programs for increased curcumin, oleoresin and essential oil production to meet the ever-increasing demand of turmeric for industrial and pharmaceutical uses. (C) 2012 Elsevier B.V. All rights reserved.