Submitted to: Eucarpia Cucurbitaceae Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: January 15, 2004
Publication Date: July 20, 2004
Citation: Zalapa, J.E., Staub, J.E., Mccreight, J.D. Genetic analysis of branching in melon (Cucumis melo L.). In: Proceedings of the 8th Eucarpia Conference, Cucurbitaceae 2004: Progess in cucurbit genetics and breeding research, July 12-17, 2004, Olomouc, The Czech Republic. p. 373-380. Technical Abstract: Plant improvement incorporating quantitatively inherited yield component traits is technically difficult, time consuming, and resource demanding. In melon (Cucumis melo L.), the inheritance of yield components is poorly understood. Yield components include branching, flowering (sex expression and earliness), and fruiting habit (fruit position, fruit number and fruit weight). Because of the importance of yield to U.S. Western Shipping melon operations, a study was designed to characterize the inheritance of branching in this melon market class. Melon progeny derived (F1, F2, F3, BC1P1, and BC1P2) derived from a cross between a U. S. Department of Agriculture line, USDA 846-1 (P1) and 'Top-Mark' (P2) were used to assess segregating progeny for yield components. Estimates of components of variance, narrow- (h2N) and broad- (h2B) sense heritabilities, and the number of least effective factors for primary lateral branch number were calculated. Lateral branch numbers among 71 to 119 F3 families tested in three commercial growing environments [California (1) and Wisconsin (2)] were significantly different (P ' 0.01). Covariance analyses among these F3 families indicates that branching is moderately heritable (h2B = 0.62 to 0.76, h2N = 0.43 to 0.48), and conditioned by several additive factors (perhaps 2 to 4) that are highly additive. Although environment plays an important role in lateral branch development, family rankings over environments were relatively consistent, indicating that effective selection for this trait could be performed in either Wisconsin or California. Because of the significant additive component underlying lateral branch number, selection of quantitative trait loci (QTL) conditioning this yield component will be likely be enhanced by the identification of genetic marker-trait associations for subsequent use in marker-assisted selection.