Seed morphological characterization, genetic diversity and association analysis in late flowering monoecious lines of castor (Ricinus communis L.)

Abstract

Castor is an important industrial oilseed crop utilized for multivarious applications. Augmenting seed yield in long duration castor varieties is of utmost importance to meet the increasing oil demand and also to make them suitable for inter/border cropping. Understanding the genetic diversity in base population of monoecious lines and interrelationship between economic traits are very much important to formulate suitable genetic improvement programmes. In this regard, seed morphological characterization and genetic diversity was assessed in 62 late flowering monoecious lines. Predominance of brown colour, ellipsoid shape and conspicuous mottling with caruncle was observed among the genotypes. Cluster analysis grouped them into eight different clusters. Maximum inter cluster distance was found between cluster VI and VIII, whereas intra cluster distance was high in cluster II. Cluster VI recorded the highest cluster mean for 100 seed weight and seed yield per plant (44.56 g and 174 g, respectively). Association studies revealed 100 seed weight and shelling percentage to be the significant traits for indirect selection of yield. In conclusion, the cluster VI has potential genotypes to utilize in developing high yielding varieties and male parent donor for hybrid breeding. The diverse genotypes identified from this study could be given priority during recombination breeding to get diverse segregants and for further molecular analysis like mapping population development and QTL/gene identification.  Keywords:  Castor, Monoecious lines, Diversity, Correlation, Path analysis