Genetic Divergent Studies in Black Turmeric (Curcuma caesia Roxb.) Genotypes

Abstract

Black turmeric (Curcuma caesia Roxb.) is a medicinally important, vegetatively propagated species for which systematic assessment of genetic divergence is useful for conservation and crop improvement. The present study assessed the genetic divergence of 33 black turmeric genotypes collected from different provenances of India. The genotypes were evaluated at ICAR-KVK Chamarajanagar, Karnataka, during 2018–19 and 2019–20 in a randomised block design with three replications. Twenty-two vegetative and yield-related characters were analysed using Mahalanobis D² statistics and Tocher’s clustering method. Fresh rhizome yield per plant contributed the highest proportion to genetic diversity (40.72%), followed by fresh weight of roots per clump (34.85%), length of primary fingers (6.63%), leaf area per plant at 180 DAS (5.87%), girth of mother rhizome (3.22%), length of mother rhizome (2.46%) and girth of primary rhizome (1.33%). The 33 genotypes were grouped into eight clusters, and clustering was independent of geographical origin. Comparatively high intra-cluster distances were observed in clusters VII and IV, indicating scope for selection within these clusters. The maximum inter-cluster distance was recorded between clusters V and VIII (173.67), followed by clusters I and V (D² = 105.35). Cluster mean analysis indicated that cluster V, containing GKM-2, GKB-3 and GKJ-5, was superior for vegetative and yield traits and may be useful for further improvement programmes.