Genetic Analysis of Important Morpho-economic Traits in Periwinkle, Catharanthus roseus (L.) G. Don

Studies were conducted with six diverse genotypes of Catharanthus roseus including one [0.5% EMS induced] mutant and one released [white with cream centre] cultivars Nirmal' and one recently released white petal with pink centre cultivar, 'Prabal' to seek the genetic information on leaf alkaloid yield by using diallel analysis. Based on the two analyses, namely genetic variance component and combining ability, both additive and non- additive genetic variances were found important in the inheritance of alkaloid and other yield contributing characters although non-additive component was higher than the additive component for most of the characters. Mean degree of dominance indicated the presence of over-dominance for most of the characters except for leaf-stem ratio.