Genetic Improvement of Yield and Fruit Traits in Snake Cucumber (Cucumis melo var. flexuosus L.) by Individual Selection

This investigation was undertaken during 2013-2016 to develop new and superior snake cucumber cultivars and to evaluate the efficiency of individual selection to improve yield in traditional snake cucumber populations. Moreover, genetic behaviour of variability was investigated. Three local cultivars were subjected to three cycles of individual plant selection and were ended up with selection of nine populations. These genotypes were evaluated in a field trial to study the behaviour of the tested populations and provide information on the nature of genetic variability and correlation among traits. The means of selected populations signify that there has been a remarkable change in all traits due to individual selection. However, the magnitudes of improvement varied within and between populations according to their genetic constitution and the basic criteria that selection was directed to. It is suggested that individual selection method improved stem length, whereas it did not considerably improve flowering time and the number of branches plant-1 in most populations. Otherwise, selection procedure resulted in isolation of superior populations with high yield production viz, AS1, DK2, DK3 and SG3. Some derived populations showed longer fruit length and lesser diameter when compared with their respective base populations.

The estimates of phenotypic coefficient of variation were higher than the estimates of genotypic coefficient of variation for all studied traits. High heritability coupled with high genetic advance was observed for stem length, fruit diameter and moderate estimates were observed for average fruit weight. Total yield was correlated with stem length, total number and weight of fruits and fruit diameter so that selection for any of these characters would result subsequently in an improvement of the total yield production. In the present study, selection procedure resulted in the isolation of superior populations with high yield production viz, AS1, DK2, DK3 and SG3. Fruit character was improved also through individual selection.