Comparative analysis of marker-assisted and phenotypic selection for yield components in cucumber

Area of Science:

• Plant breeding
• Quantitative genetics
• Crop improvement

Background:

• Theoretical studies indicate marker-assisted selection (MAS) may surpass phenotypic selection (PHE) for quantitative traits.
• Empirical comparisons of MAS and PHE within plant breeding programs are limited.

Purpose of the Study:

• To directly compare the effectiveness of MAS and PHE in a cucumber breeding program.
• To evaluate selection for yield-component traits influencing overall yield.

Main Methods:

• Four cucumber inbred lines were intermated to create base populations.
• Three cycles of recurrent mass selection were applied: PHE, MAS, and random mating.
• Selection targeted four quantitatively inherited yield-component traits: branching, gynoecy, earliness, and fruit length-to-diameter ratio.

Main Results:

• Both MAS and PHE improved traits in at least one population, with exceptions for earliness under MAS.
• Response to selection depended on population and trait, with inferior maternal parents yielding favorable responses.
• PHE was generally more effective for gynoecy, earliness, and fruit ratio, while MAS excelled in branching and increased yield (fruit per plant).

Conclusions:

• MAS and PHE are useful for multi-trait improvement in cucumber breeding.
• The relative effectiveness of MAS and PHE is trait- and population-specific.
• MAS demonstrated a unique advantage in increasing fruit yield per plant.