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 F 3 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 F 4 and F 5 progeny sets. RIL, crossing parents, and F 3 -F 5 progeny sets were then evaluated under replicated field conditions for fruit yield and quality (L:D and E:T) to evaluate gain from selection (DG). 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 (F 4 -F 5 generation; C 2 ). Lack of DG during advanced generations (F 4 -F 5 ) of MAS was likely due to allelic fixation and/or optimized epistatic complementation.

A high-density linkage map and QTL mapping of fruit-related traits in pumpkin (Cucurbita moschata Duch.)

“…The developed SNP markers linked to fruit-related traits in the loci facilitates molecular breeding of new varieties through marker-assisted selection (MAS). It has been proved effective for improving quantitative and qualitative traits in cucumber 53 – 56 , melon 57 , 58 , watermelon 59 , 60 even Cucurbita species, C. pepo 61 . However, it was still in its infancy for application in C. moschata .…”

Vegetable Breeding Strategies

“…This will help breeders in shifting traditional breeding to marker aided selection. Gene pyramiding has been proposed and applied to enhance resistance to disease and insects by selecting for two or more than two genes at a time [41][42]. The advantage of use of markers in this case allows to select for QTLallele-linked markers that have same phenotypic effect [43].…”

Genetic Improvement of Fresh Market Tomatoes for Yield and Fruit Quality Over 35 Years in North Carolina: A Review

“…Bertoldo et al (2010) reported the genetic gain (genetic improvement toward desirable changes) at 14% for pod diameter in common beans (Phaseolus vulgaris L.), whereas there were negative gains for number of pods/plant and number of seeds/pod. Genetic gain between generations (F 3 to F 5 ) was not encouraging in cucumber (Cucumis sativus L.), most likely because contributing alleles were already fixed in the genome (Behera et al, 2010). Similar studies in tomato indicated that response to selection could be improved for cold stress and drought stress tolerance (Foolad et al, 2003).…”