Response to phenotypic and marker-assisted selection for yield and quality component traits in cucumber (Cucumis sativus L.)

Abstract

Two cucumber recombinant inbred lines (RILs) differing in plant habit were crossed and progeny self-pollinated to produce F3 individuals upon which phenotypic selection was practiced to identify a base population which in turn underwent either two cycles of MAS or random mating without selection (RAN). MAS and RAN were practiced to produce F4 and F5 progeny sets. RIL, crossing parents, and F3–F5 progeny sets were then evaluated under replicated field conditions for fruit yield and quality (L:D and E:T) to evaluate gain from selection (ΔG). The broad-sense heritability (h 2 B) over cycles (C) of selection ranged 0.22–0.45, 0.09–0.20, and 0.11–0.15 for yield, L:D, and E:T, respectively. Although one cycle of PHE selection followed by MAS was effective in conserving the performance of the traits examined during inbreeding, progeny performance during RAN fluctuated (F4–F5 generation; C2). Lack of ΔG during advanced generations (F4–F5) of MAS was likely due to allelic fixation and/or optimized epistatic complementation.