Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract only
Publication Acceptance Date: 11/6/2005
Publication Date: 11/6/2005
Citation: Mebrahtu, T., Mohamed, A., Devine, T.E. 2005. Combining ability analyses of vegetable soybean genotypes for sugar contents and pod dimensions [abstract]. ASA-CSSA-SSSA Annual Meeting Abstracts [CDROM]. Salt Lake City, Utah: ASA-CSSA-SSSA. Interpretive Summary:
Technical Abstract: Few studies have evaluated vegetable soybean (Glycine max [L.] Merr.) for individual sugar content when harvested at reproductive stage (R6-R7). Genetic information on combining ability and the type of gene action that governs the inheritance of seed traits can help in selection of suitable parents and the appropriate breeding procedure. The objectives of this study were to obtain information on the inheritance of traits and to identify best parents for hybridization. A 10 x 10 diallel crosses were made and generated F2 and F3 progeny. The progeny were planted at Virginia State University Research Farm, Petersburg, Virginia and harvested at green pod stage. Pod dimensions (pod length, width, and thickness) and hundred pod weights (HPW) were measured. Green beans were shelled and analyzed for fructose, glucose, sucrose, raffinose, and stachyose contents. The results showed that estimates of both the combining ability (general and specific), and reciprocal variances were significant for seed traits analyzed, pod dimensions, and HPW. However, the magnitude of general combining abilities (GCA) were higher than the specific combining ability (SCA) variances, indicated the predominant role of additive genetic variance. The GCA to SCA ratios for seed traits ranged from 1.39 to 6.80 for the F2 progeny and from 2.72 to 22.92 for the F3 progeny. The parents Kanrich and V81-1603 showed high and stable GCA for sucrose and HPW from generation to another. Additionally Verde, V81-1603 and PI 399055 showed with high GCA for pod dimensions. In general high sucrose content was observed in early maturity group genotypes with large pod size.