GENETIC DIVERSITY, CORRELATION AND PATH CO-EFFICIENT ANALYSIS IN SWEET GOURD (Cucurbita moschata L.)

Abstract

Twenty seven genotypes of sweet gourd (Cucurbita rnoschasa L.) were studied in a field experiment at the experimental field of Sher-e-Bangla Agricultural University. Dhaka, during March 2010 to September 2010. Among them, six genotypes did not germinate. Sweet gourd is a nutrient powerhouse, low in fat and calories and rich in disease fighting nutrients such as a-carotene, 13-carotene, fiber. vitamin-C & E. K. Mg. pantothenic acid. There are significant quantities of the carotinoids like lutien and zeaxanthin, both of which helps to maintain eye health. It's an important summer vegetable and very adaptive to climate change. Lack of high yielding, disease and pest tolerant varieties is the main constrains towards its production. Among the cultivated land races, a wide range of genetic variability exists in this crop that can be exploited for its improvement. The objectives of the study were to measure the variability among the genotypes for yield and yield contributing characters, estimate genetic parameters, association among the characters and their contribution to yield. This helps to choose desirable parents for establishing new breeding population. High genotypic co-efficient of variation (GCV) was observed for fruit yield per plant, number of male flower per plant and number of female flower per plant. Low genotypic co-efficient of variation (GCV) was observed for days to first female flowering, days to first male flowering and fruit length. In all cases phenotypic variances were higher than the genotypic variances. High heritability with high genetic advance in percent of mean was observed in yield per plant, number of male flower, pedicel length of female flower, and pediccl length of male flower indicated that these traits were under additive gene control and selection for genetic improvement for this trait would be effective. Correlation studies revealed that highly significant and positive association of yield per plant was found with number of female flower followed by fruit length, number of male flower, fruit breadth and fruit weight at both genotypic and phenotypic level. Path co-efficient analysis revealed that maximum direct contribution towards yield per plant with traits of number of female flower followed by number of male flower and days to first male flowering. The highest intra-cluster distance was found in cluster V. low in IV and no distance was found in cluster I. Among six clusters the highest inter cluster distance was observed between cluster H and cluster Ill and the lowest between cluster IV and cluster V. Considering all the characters the G21 (BD-2 150), G1 (1313-2151). G11 (BD 2229) and G13 (BD 266) genotypes were selected for futurc breeding programme.