The diallel analysis technique allows the breeder to estimate the rela-tive importance of general and specific combining ability for important traits in terms of the nature of gene action. Information on these systems is of value in the development of soybean hybrids as well as in the development of pure-line varieties. In this study, a primary objective was to determine the...
By Soybean Genetics Newsletter, Published on 04/01/87
To determine the number of genes determining cold resistance, the method proposed by Merezhko (1983) was used. According to the distribution of the F2 plants, it was concluded that the part of the progenies like a recessive parent averaged 25%. From this, we concluded that parental forms in the crosses differ from each other by the alleles of one gene.
Cold-resistant varieties 'Comet
Soybean is often characterized by hardseededness or seed impermeability, when the seeds do not imbibe water and they germinate very slowly. Germination period of such seeds is very prolonged for a month or more. Hardseededness is caused by reduced water permeability of seed coat. We meet this character in many plant species, but more often in Leguminosae, Rosaceae, Lilium...
Developing of cold-tolerant soybean varieties is one of the new main trends in soybean breeding. Such studies were started in the USA (Veitenheimer et al., 1984; Unander and Orf, 1984; Harrison and Nickell, 1984; Hillsman et al., 1977; Hicks, 1978; Seddigh and Jolliff, 1984; Littlejohns and Tanner, 1976; Hume and Jackson, 1981; Voldeng et al., 1984; Sanbuichi, 1980; Goto and...
We tested gradient PAGE gels for their ability to resolve isozymes with a specific SOD (EC 1.15.1.1) stain as well as with a nonspecific TO stain. In particular, we wanted to test gradient gels for use in scoring F2 seeds segregating for the cultivar-specific type 1 and type 3 TO zymogram patterns first reported by Gorman and Kiang (1977). TO electrophoretic bands are caused by...
There have been numerous papers dealing with amylase isozymes in soybeans (i.e., Morita and Yagi, 1979; Hildebrand and Hymowitz, 1980; Kiang, 1981; Adams et al., 1981; Mikami et al., 1982). All have reported beta-amylase as the predominant amylase type in most soybean lines and that varietal differences in beta-amylase either for electrophoretic mobility, pl, or enzyme activity...
Soybean isozymes have been studied genetically primarily with simple PAGE and starch gel electrophoresis (see Rennie et al., 1986, for a comparison and Kiang and Gorman, 1983, or Palmer et al., 1985, for reviews). Our objective was to test if the use of vertical gels with a PAGE concentration gradient would enhance isozyrne resolution over simple horizontal PAGE gels. Gradient...
Many of the widely grown soybean cultivars in the Mid-Atlautic region are susceptible to phytophthora rot caused by Phytophthora megasperma f. sp. glycinea Kuan and E?:"Win (Pmg). There is limited information available on tolerance to Pmg in these popular soybean cultivars. Tolerance or field resistance to Pmg in soybean is characterized as race nonspecific resistance involving...
In 1983, 1984, and 1985, the senior author collected wild perennial Glycine species in the South Pacific (New Caledonia, Vanuatu, Tonga) and in Australia (Queensland including Great Barrier Reef islands, Western Australia, Northern Territory). The collecting trips were sponsored by the Rockefeller Foundation and the International Board of Plant Genetic Resources. The latter...
Glycine tabacina (Labill.) Benth. and G. tomentella Hayata have both diploid (2n=2x=40) and tetraploid (2n=4x=80) forms (Singh and Hymowitz, 1985a). Although the diploid plants-ca; be distinguished cytologically from the tetraploids, the procedure is tedious, and requires precious greenhouse space. Seed isozyme analysis may prove to be a simpler approach for differen-tiating...
Two isozyme variants of seed urease are present in soybeans. These variants are referred to as electrophoretically fast and slow on polyacrylamide gels (Buttery and Buzzell, 1971; Polacco and Havir, 1979). Kloth and Hymowitz (1985) demonstrated that the urease isozymes are codominantly inherited. They assigned the gene symbol Eul-a to the slow-moving allele and Eul-b to the fast...
Columbia lance nematode, CLN [Hoplolaimus columbus Sher], is a migratory endo-and ectoparasite of soybean and commonly causes yield reductions of up to 30% in tolerant cultivars. Complete crop failure may occur on moisture-stressed or susceptible cultivars. First recognized as a major parasite of cotton and soybean in 1967 (Fassultiotis et al., 1968), CLN now infests a large...
A series of seven differential strain groups of SMV, labelled Gl to G7, were reported by Cho and Goodman (1979). Buzzell and Tu (1984) added another strain, G7A, and Lim (1985) added an additional strain, Cl4. We have been studying the genetic relationships among the cultivars that define the strain groups. Our intial studies involved the cultivars 'Marshall', 'Kwanggyo', 'York...