Genetic Divergence in Sunnhemp [Crotalaria juncea (L.)]

Background: Sunnhemp is a very important green manuring crop. The crop is utilized for various purposes like reducing soil erosion, improving soil properties and recycling plant nutrients. The knowledge regarding the crop is still not exploited, due to lack of research in this crop. So, the present study was conducted to know the extent of genetic diversity present in the crop. From the divergence analysis, it may be concluded that the genotypes belonging to different clusters separated by high estimated statistical distance may be used in the hybridization programme for developing high green biomass yielding sunnhemp varieties. Methods: A field experiment was conducted at the research farm of Department of Genetics and Plant Breeding, Navsari Agricultural University, Navsari, Gujarat with thirty sunnhemp genotypes to know the extent of genetic diversity by D2 analysis in a randomized block design during late Kharif 2017. Result: The analysis was conducted for D2 analysis and was concluded from D2 analysis that, the characters viz., days to 50% flowering, fresh weight of root nodules per plant, fresh weight of plant, root nodules per plant, leaf length, root length, dry weight of root nodules per plant, C: N ratio, internodes per plant, plant height and stem diameter contributed towards the genetic divergence. Traits like primary branches per plant and leaf area didn’t contribute towards genetic divergence. The thirty genotypes were grouped into seven clusters following Tocher’s method (Rao, 1952). The cluster III was largest having eleven genotypes. Cluster IV and cluster II was second largest which contained seven and five genotypes respectively. Cluster I and cluster V contained three and two genotypes respectively Cluster VI and VII had only one genotype. The intra cluster distance was more in cluster III and the inter cluster distance was maximum between cluster V and cluster VII.