Genetic variability and correlation studies in snake gourd (crichosanthos anguina L.)

Abstract

Studies were undertaken with 25 diverse snake gourd types in the Department of Horticulture (Olericulture), College of Horticulture, Vellanikkara, to estimate the genetic variability, correlation coefficients and path coefficients in the crop, during 1977-78. The results have shown that the differences between the types were highly significant for all the 21 characters studied. The estimates of variance components and coefficients of variation have indicated that the major portion of total variability in most of the characters was due to genetic causes, heritabllity in the broad sense was found to be quite high for most of the characters but the heritabllity estimate of yield was only 45.90 per cent. The estimate of genetic gain has shown that by selecting five per cent superior plants from the available population, yield can be improved upto 35.66 per cent over the mean. Characters such as per cent ash content, crude protein per cent, percentage P, number of female flowers per plant, weight of individual fruit and vitamin C content which exhibited parallelism in the high estimates of heritabillty and genetic gain may be suggested to be due to the action of additive genes and can be straightly improved through selection. The type T.A.19 was found to be the highest yielder. Yield per plant was found to be highly associated with number of primary branches, days for opening of first female flower, weight of individual fruit, length of fruit and girth of fruit. The correlation coefficients among these yield components were also significant. Path coefficient analysis has shown that weight of individual fruit, girth of fruit, number of fruits per plant and node at which first female flower appeared are the more important characters contributing to yield, on account of their high direct effects. Number of female flowers per plant and length of fruit are also important characters as their direct effects were moderate and indirect effects substantial.