Estimation of Genetic Parameters in Selected Cucumber (Cucumis sativus L.) Hybrids.

Document Type : Original Article

Authors

Vegetable Research Department, Horticulture Research Institute, Agric. Research Center, Giza, Egypt.

Abstract

Cucumber breeders are dedicated to understanding the complexities of diversity to devise effective breeding strategies. The study was conducted in a greenhouse in Vegetable Research Department (VRD), Horticulture Research Institute (HRI), Agricultural Research Center, Egypt, during 2021and 2022. A half-diallel cross among five cucumber genotypes and ten hybrids was investigated to estimate several genetic parameters. Results revealed substantial variation between the investigated genotypes for all characteristics. F1hybrids P3XP4, P3XP5 and P4XP5 recorded the highest heterosis effect for yield and its constituent traits compared to mid and better parent values. Mean squares for both general and specific combining ability were extremely significant for whole characters. The magnitudes of GCA were greater than those corresponding magnitudes of SCA indicating predominance of non-additive type of gene effects with regard to plant height, number of leaves/plant, early yield/plant, fruit length, fruit diameter, fruit shape index, average fruit weight, number of fruits/plant  and total yield/plant traits. The findings suggested that P4 and P5 were the greatest combiners for all characters and considered to be promising parents. The good cross combinations for the majority of traits were recorded in the following F1 hybrids: P3XP4, P3XP5, and P4XP5.Genetic analysis revealed that dominance variance (σ²D) exceeded additive variance (σ²A), and dominance degree was >1 for most traits except fruit length, fruit number, and total yield per plant, suggesting the importance of non-additive gene effects for such traits. Broad sense-heritability was greater than narrow sense-heritability for whole traits. These findings supported the use these genotypes to local seed production programs in Egypt.

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