Submitted to: Plant Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/20/2008
Publication Date: N/A
Interpretive Summary: Edamame is a large seeded vegetable soybean used for human consumption. Edamame is a healthy vegetable highly valued in the human diet in Japan and China. The health conscious America consumer, inspired by the ethnic Asian population, is consuming increasing quantities of this valuable vegetable product. As a result imports of edamame from Asia have grown rapidly in recent years. Locally produced edamame can produce a fresh product for the American market if soybean cultivars are bred for adaptation to cultivation on American farms. Flavor and sweet taste are important factors in producing a crop acceptable to consumers. This study describes the inheritance of sugar and protein content of edamame type soybeans and provides a breeding strategy for developing sweet tasting edamame for American farm production. This information will increase the efficiency of US edamame breeding programs and speed the availability of this vegetable to the American consumer. Cultivation of adapted edamame varieties will also benefit American farmer's income especially those transitioning from tobacco cultivation to this healthy food source.
Technical Abstract: Few studies have evaluated vegetable soybean (Glycine max [ L.] Merr.) for individual sugar content when harvested at the reproductive stage (R6-R7). Genetic information on combining ability and the type of gene action that governs the inheritance of seed traits can greatly help the breeder select suitable parents and the appropriate breeding procedure. Therefore, ten vegetable soybean lines including cultivars, plant introductions, and experimental lines were crossed using a complete diallel mating design (including reciprocals). Parent lines and F2 and F3 progenies were evaluated for three nutritional components. This study showed that both general (GCA) and specific combining ability (SCA) and reciprocal effects were significant for sucrose, total sugar, and protein. The sucrose, total sugar, and protein ratios of the general to specific combining ability variances for sucrose ranged from 0.188 for F2 to 0.462 for F3, for total sugar from 0.227 for F2 to 0.501 for the F3, and for percent protein from 0.433 for F2 to 0.579 for F3, indicating that prediction of hybrid combination cannot be made on GCA effects alone. Genotype x year effects was significant in both F2 and F3 analysis. Cultivars Kanrich, Pella, Verde, and experimental line V81-1603 were good general combiners for sucrose. Thus, they could be utilized for breeding high sucrose genotypes. In general, high sucrose contents were observed in progeny of early maturity group genotypes Kanrich, Pella, and Verde. The sucrose content of these genotypes was consistently high from one generation to another. The best combiners for total sugar were Verde, V81-1603, and PI 399055. The best combiners for protein were PI 379621, V81-1603, and Late Giant. These genotypes could serve as genetic sources in a vegetable soybean breeding program.