|Sun, Zhanyong - UNIV OF WI MADISON|
|Lower, Richard - 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: Sun, Z., Lower, R.L., Staub, J.E. Generation means analysis of parthenocarpic characters in a processing cucumber (Cucumis sativus L.) population. In: Proceedings of the 8th Eucarpia Conference, Cucurbitaceae 2004: Progress in cucurbit genetics and breeding research, July 12-17, 2004, Olomouc, The Czech Republic. p. 365-372. Technical Abstract: The incorporation of genes for parthenocarpy (the production of fruit without fertilization) into processing cucumber (Cucumis sativus L.) can provide a means for increasing fruit yield and quality. The inheritance of parthenocarpy in this horticulturally important market class is not well understood. Thus, the inheritance of parthenocarpy was investigated in segregating generations derived from a line 2A (P1, parthenocarpic) x Gy8 (P2, non-parthenocarpic) mating. A Generation Means Analysis was applied to yield data from six generations [P1, P2, F1, F2, BC1 (F1 x P1), and BC2 (F1 x P2)] collected at two locations [Arlington (greenhouse) and Hancock (open -field), WI] in two years (1999 and 2000). The number of effective factors controlling parthenocarpy was estimated to be more than one. An additive-dominance model adequately explained the variation in generation means of the Arlington grown populations. A model that included additive x additive interaction and dominance x dominance interaction was necessary to explain the variation in generation means of the Hancock grown populations. Duplicate epistatic effects were detected at both locations. Data from the Hancock location indicated the presence of parthenocarpic genes in both parental lines. Narrow-sense heritability estimates ranged from 0.15 to 0.56 across locations and years. The direction of the dominance effect changed depending on environment. These results suggest that selection will likely be effective for increasing the degree of parthenocarpy in the environments tested, however, the amount of gain from selection for this trait will be environmentally dependent.