Studies on genetic variability and correlations in china aster (Callistephus chinesis Nees.)

Abstract

Wide and significant variations for all the 12 characters were observed among the 38 genotypes of China aster studies. The difference between phenotypic and genotypic coefficient of variation was medium for a number of laterals per plant and narrow for the remaining characters. High heritability as well as high genetic gain were observed for flower weight and number of ray florets, whereas medium heritability along with high genetic gain was observed for number of laterals per plant. High heritability accompanied by medium genetic gain was found for plant height, plant spread, stalk length and stem girth. Stalk length had positive and significant correlations with plant height, plant spread, number of laterals per plant, number of flowers per plant, days to flower, flower size, flower weight and number of ray florets per head. Positive and significant associations were observed between flower size and each of the following seven characters, viz., plant height, plant spread, stalk length, number of laterals per plant, days to flower, flower size, flower weight and number of ray florets per head. Number of flowers per plant exhibited positive and significant relationship with plant height, plant spread, stalk length, number of main branches per plant, number of laterals per plant and days to flower. Path coefficient analysis revealed that plant height and plant spread were the major factors influencing stalk length directly. Number of flowers per plant, number of ray florets per head and flower size were also important as their total indirect effect on stalk length was high. Flower size was found to be influenced directly by stalk length, number of ray florets per head and plant spread. Plant height and the maximum total indirect effect on flower size., number of laterals per plant had the maximum direct effect on number of flowers per plant. This was followed by number of main branches per plant. Selection showed that selection based on 11 characters would be more efficient than straight selection to an extent of 42.5% in stalk length and 21.5% in number of flowers per plant, but there was practically no improvement over straight selection in flower size. 127