GENETIC VARIABILITY AND INTER RELATIONSHIP AMONG YIELD AND ITS CONTRIBUTING TRAITS OF SWEET GOURD (Cucurbita maxima L.)

Abstract

A field experiment was conducted with 28 sweet gourd (Cucurbita maxima L.) genotypes at the experimental field of Sher-e-Bangla Agricultural University, Dhaka to determine the genetic variability, correlation and path coefficient for yield and its contributing traits during November’ 2019 to March’ 2020. Significant variation was present among all the genotypes for studied traits. Mean comparison table shows variation exist among all the fourteen characters. Phenotypic variance (δ 2 p) and phenotypic coefficient of variation (PCV) was higher than the genotypic variance (δ ii 2 g) and genotypic coefficient of variation (GCV) for all the traits under studied. High heritability coupled with high genetic advance in percent of mean was observed for pedicel length of male flower (98 cm and 46.38 cm), inter node distance (97 cm and 43.85 cm), leaf breadth (96 cm and 41.74 cm), pedicel length of female flower (94 cm and 23.36 cm),) respectively which indicated the effect of additive genes. The correlation coefficient revealed that fruit yield per plant had the highly significant positive correlation with fruit weight (r g = 0.721, r p = 0.807), fruit per plant (r g

= 0.585, r p = 0.588), pericarp length (r g = 0.669, r p = 0.222), indicating those characters can be considered for phenotypic selection for future sweet gourd improvement program. The path coefficient had direct positive effects with fruit weight (0.802), fruit per plant (0.565), Pericarp length (0.670), number of male flower (0.036) which indicated that promising selection would be rewarding for those traits. The genotypes are grouped into five clusters, where cluster IV comprise maximum genotype (9) and cluster I had minimum genotypes (3). The highest intra cluster distance was observed in cluster I (3.352). Among five clusters the highest inter cluster distance was observed between cluster I and cluster III (3.735) and the lowest between cluster I and cluster IV (2.294). Considering genetic variation, leaf length without petiole (cm), fruit size (cm), fruit per plant, fruit weight (kg) cluster analysis, intra and inter cluster distance, agronomic performances BD-2150, BD- 2175, BD-282 might be selected as promising parents for future hybridization program.