|Lopez Sese, Ana Isabel - UNIV OF WISCONSIN|
Submitted to: Cucurbit Genetics Cooperative Report
Publication Type: Research Notes
Publication Acceptance Date: May 1, 2002
Publication Date: December 10, 2002
Citation: Lopez Sese, A., Staub, J.E. 2002. Selection for early flowering, branching and gynoecy in cucumber (cucumis sativus l.). Cucurbit Genetics Cooperative Report. Technical Abstract: The use of exotic germplasm has allowed for the incorporation of disease resistant genes (e.g., PI 198087, PI 196289, PI 220860), and opportunities to change plant architecture in cucumber. This has resulted in the development and release of lines with unique branching and flowering habits. One of these plant types that has potential for increasing the yield of cucumber is one which is gynoecious, determinate and multiple lateral branching. In theory, earliness is encouraged in gynoecious flowering, and plants of shorter stature (i.e., determinate) with many lateral branches might be expected to produce a larger amount of early fruit in a reduced field space. There are, however, problems associated with the selection of plants that possess multiple lateral branching in a determinate background. The problems involve the difficulty of vegetative propagation during breeding and the inability to select determinate plants in a multiple lateral branching background. This can be over come by indirect selection for DNA markers associated with target traits. We have been attempting to introduce multiple lateral branching originating from exotic germplasm into commercially acceptable gynoecious lines through phenotypic selection. The research described herein provides information on the use of the mutiple lateral lines H-19 (University of Arkansas) and WI 5551 (USDA) during backcrossing to the commercially acceptable lines G421 (released by the University of Wisconsin and North Carolina State University as GY7) and GY14 (released by Clemson University). Based on the differences between traits among generations (F1, F2, F3, BC1, and BC2), correlations among traits examined (leaf type, flowering date, sex expression, lateral branch number), and their phenotypic similarities observed in the parents and progeny examined herein, it appears that the development of multiple branching, gynoecious, early flowering germplasm with either leaf type will be difficult. Nevertheless, the variation for the characters selected suggests that further selection in some families might result in the capture of unique individuals having potential for increasing early yield in processing cucumber while retaining acceptable fruit quality.