Assessment of genetic parameters for diversified traits in periwinkle (Catharanthus roseus L.) through diallel analysis

Abstract

Knowledge on complexion and level of genetic variability exist in the genotype as well the association among the different characters being indispensable for improvement in various traits. The present investigation was carried out to estimate the nature and level of genetic variability among six different inbred lines of periwinkle such as Vi-15-1, Vi-13-2, Vi-16, Vi-15-2, Vi-29 and Vi-14-3 as well as their thirty crosses combinations for ornamental characters. The highly significant variations between genotypes indicate the presence of variability in the investigated traits. The range was 5.35 to 34.41 in phenotypic coefficient of variations and 3.96 to 34.02 in genotypic coefficient of variations among the parental lines. High phenotypic and genotypic coefficient of variations among cross combinations recorded for plant spread, branches/plant and number of seeds/follicle. Moderate to high heritability together with high per cent of genetic advance was recorded for plant height, spread, primary branches per plant, internode length, follicle length and seeds/follicle among the parents. Among the cross combinations plant height, plant spread, branches/plant, internode length, flower diameter, follicle length and number of seeds/follicle have shown moderate to high heritability and high genetic advance (%). It was suggested that these characters were controlled by the additive gene action and further improvement could be achieved by selection for enhancement of ornamental traits.