Characterization of selected curcuma species germplasm using morphological and molecular markers

Abstract

Curcuma L., a perennial rhizomatous herb, is gaining global importance as a source of starch besides its medicinal property and use as a spice. Characterization of germplasm is very essential in crop plants and it is the basis for selection of accessions for use in crop improvement programmes. This research work was an attempt to characterize the fifteen selected accessions in eight species of Curcuma collected from different parts of India and maintained in the field gene bank of ICAR-CTCRI using morphological and molecular markers. Two accessions in each of C. amada, C. angustifolia, C. aromatica, C. decipiens, C. malabarica, C. raktakanta, C. zedoaria and one of C. longa were selected. These 15 accessions were morphologically characterized using 13 qualitative and 15 quantitative traits and a wide variability was observed. Dendrogram based on the morphological characters grouped the genotypes into four clusters. PCC analysis revealed that the accessions of the same species have shown more than 83% similarity except C. angustifolia. C. raktakanta accessions have shown a highest intra-specific similarity of 94%. C. decipiens accessions were found to be the highly variable from the most commonly exploited species C. longa while C. aromatica has shown highest similarity. PCA showed that the characters such as leaf midrib colour, rhizome flesh colour, leaf texture and aroma of rhizome have contributed mostly to the variability. Molecular characterization was done using 10 ISSR and 7 SSR markers. The total percentage polymorphism obtained by ISSR characterization was 94.31 while it was 91.11 percentage in the SSRs. C. angustifolia-1 was found to be highly variable from C. angustifolia-2 suggested the occurrence of intraspecific variability. The intra-specific similarity among C. raktakanta accessions were found to be highest than all other accession pairs. Clustering based on ISSR markers grouped the genotypes into five clusters while SSRs into six clusters. Mantel’s test showed a positive correlation between the morphological and molecular data. The results of the present study indicated that the morphological as well as the molecular tools were found to be very effective in the characterization of germplasm of Curcuma species for the developement of core collections and for further use in the crop improvement programmes.