|Robbins, Matthew - UNIV OF WI MADISON|
Submitted to: Eucarpia Cucurbitaceae Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: January 15, 2004
Publication Date: July 20, 2004
Citation: Robbins, M.D., Staub, J.E. Strategies for selection of multiple quantitatively yield components in cucumber. In Proceedings of 8th Eucarpia Conference, Cucurbitaceae 2004: Progress in cucurbit genetics and breeding research, July 12-17, 2004, Olomouc, The Czech Republic. p. 401-410. Technical Abstract: Cucumber is an important vegetable crop whose yield has reached a plateau in the last15 years. Factors, such as fruit-set inhibition, a narrow genetic base, and negative correlations among yield-related traits must be overcome to increase yields. A study has been designed and initiated to compare recurrent phenotypic (PHE) and marker-assisted (MAS) selection for relative efficiency. Selection was practiced on four yield-related traits over three cycles in each of four base populations originally created from the intermating of four inbred lines. The PHE selection strategy requires identification of unique plants in the open-field and then their recovery through meristem cuttings followed by cross pollination in a greenhouse. These plants are early flowering, gynoecious, multiple lateral branching, and develop relatively long fruit. The MAS strategy involves the selection of greenhouse-grown individuals by assessment of genotype using dominant (RAPD, SCAR, SNP, and AFLP) and codominant (SSR and SCAR) markers linked to QTL for the yield components described for PHE selection. There are several critical decision points for MAS including QTL selection, identification of markers most appropriate for MAS, and marker optimization. Decision-making requires compromises associated with QTL map position, marker efficiency maximization, and choice of marker type.