ARS | Publication request: RESPONSE TO PHENOTYPIC SELECTION FOR MULTIPLE LATERAL BRANCHING IN CUCUMBER(CUCUMIS SATIVUS L.)

Submitted to: Cucurbit Genetics Cooperative Report
Publication Type: Research Notes
Publication Acceptance Date: July 15, 2000
Publication Date: N/A

Technical Abstract: The yield of pickling cucumber (gynoecious or G, and monoecious or M) has plateaued in the last 15 years. Studies suggest that this recent plateau may be associated with net photosynthetic capacity. Resource limitations may explain why fruit developing from the first pollinated flower on each lateral branch inhibits the development of subsequent fruits. This plateau might be overcome by manipulating cucumber plant architecture to develop high yielding genotypes. This experiment reports gain from selection made when breeding for small stature, multiple branching (MLB) genotypes. The mean MLB number of the 126 selected plants in the BC I population was 4.90. Since approximately 4.4 percent (corresponding to a calculated selection intensity of 1.058) of the BC1 population was selected, the expected gain from selection was calculated to be 0.57 units. The realized gain from selection based on the difference of the generation means was approximately 0.4 units. The progressive changes (increase in MLB) in these generations are the result of selection and increased homozygosity (BC 1 S 1; fixation) of loci affecting this trait.