Progress 10/01/03 to 12/31/04
Outputs
Vegetable soybean is a large-seeded with Japanese pedigree widely consumed in Japan, China and Taiwan, and is currently gaining consumer acceptance in the United States. Breeding vegetable soybeans for the US environment and consumers necessitates a broad genetic basis of the germplasm for desired traits. The objective of this study was to determine the genetic diversity of germplasm materials at Virginia State University (VSU), in order to guide the choice of parents to be used in the vegetable soybean-breeding program. Ninety-six soybean accessions (consisting of 82 breeding lines, 2 VSU improved vegetable cultivars, 8 grain-type cultivars and 4 other vegetable lines) from different maturity groups were planted in greenhouse, leaf samples taken for DNA isolation and analysis. The genetic diversity of the accessions was evaluated using eight SSR (simple sequence repeat) markers sampled from six soybean genome linkage groups. In total, 37 alleles were detected ranging
from 1 to 12 per SSR. The average number of alleles per locus was 4.6. The loci with the most and least alleles were satt148 (12 alleles) and GMGLPSI2 (1allele), respectively. The genetic similarity values between accessions were used to produce a dendrogram. Almost all accessions (91/5) could be distinguished, and clustered in 14 major groups. Whereas, the breeding lines did not form a complete separate cluster from the grain-type, some USDA breeding lines were genetically different from the bulk of VSU lines. Although a limited number of SSR markers were used, they provided sufficient polymorphism to fingerprint and distinguish 91 soybean accessions. In addition to the general SSR markers, fourteen specific SSR markers that were linked to loci associated with sugar and protein contents in soybean were evaluated separately. These markers detected 164 alleles with the SSR marker satt 276 detecting the highest number of alleles (25), while satt 404 detecting the least number of alleles
(6) in the analyzed accessions. The combination of the 22 SSR markers was adequate to distinguish all analyzed accessions.
Impacts
The current molecular breeding aspect of soybean is just in initial phase and thus no impact yet to report. Nevertheless, the results of the present studies show that there is a need to seek for additional sources of genetic material in order to widen the current genetic diversity of the VSU vegetable soybean breeding lines. The new sources of sucrose and protein content germplasm will be useful in genetic improvement of vegetable soybean for consumers. This will definitely improved consumer's health and generate revenue for producers.
Publications
- No publications reported this period
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Progress 01/01/04 to 12/31/04
Outputs
Vegetable soybean is a large-seeded with Japanese pedigree widely consumed in Japan, China and Taiwan, and is currently gaining consumer acceptance in the United States. Breeding vegetable soybeans for the US environment and consumers necessitates a broad genetic basis of the germplasm for desired traits. The objective of this study was to determine the genetic diversity of germplasm materials at Virginia State University (VSU), in order to guide the choice of parents to be used in the vegetable soybean-breeding program. Ninety-six soybean accessions (consisting of 82 breeding lines, 2 VSU improved vegetable cultivars, 8 grain-type cultivars and 4 other vegetable lines) from different maturity groups were planted in greenhouse, leaf samples taken for DNA isolation and analysis. The genetic diversity of the accessions was evaluated using eight SSR (simple sequence repeat) markers sampled from six soybean genome linkage groups. In total, 37 alleles were detected ranging
from 1 to 12 per SSR. The average number of alleles per locus was 4.6. The loci with the most and least alleles were satt148 (12 alleles) and GMGLPSI2 (1allele), respectively. The genetic similarity values between accessions were used to produce a dendrogram. Almost all accessions (91/5) could be distinguished, and clustered in 14 major groups. Whereas, the breeding lines did not form a complete separate cluster from the grain-type, some USDA breeding lines were genetically different from the bulk of VSU lines. Although a limited number of SSR markers were used, they provided sufficient polymorphism to fingerprint and distinguish 91 soybean accessions. In addition to the general SSR markers, fourteen specific SSR markers that were linked to loci associated with sugar and protein contents in soybean were evaluated separately. These markers detected 164 alleles with the SSR marker satt 276 detecting the highest number of alleles (25), while satt 404 detecting the least number of alleles
(6) in the analyzed accessions. The combination of the 22 SSR markers was adequate to distinguish all analyzed accessions.
Impacts
The current molecular breeding aspect of soybean is just in initial phase and thus no impact yet to report. Nevertheless, the results of the present studies show that there is a need to seek for additional sources of genetic material in order to widen the current genetic diversity of the VSU vegetable soybean breeding lines. The new sources of sucrose and protein content germplasm will be useful in genetic improvement of vegetable soybean for consumers. This will definitely improved consumer's health and generate revenue for producers.
Publications
- No publications reported this period
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Progress 01/01/03 to 12/31/03
Outputs
This project culminated in Spring 2003 by the release of 11 cultivars for planting by interested soybean growers. In the quest for exploring new seed traits, the current investigation included high sucrose, high protein content, low lipoxygease, and high isoflaovone content as target traits to be incorporated in vegetable soybeans. In that quest, the use of molecular markers to identify quantitative trait loci (QTLs) has the potential to enhance the efficiency of trait selection in soybean breeding. The purpose of the present project was to identify QTLs for sugar content and lipoxygenase in vegetable soybean population segregating for these traits. The amount of isoflavones, sugar and other bioactive components in soybean seed varies by year, environment and genotype. Thus genetic markers closely linked to genes controlling these traits may be used to indirectly select for favorable alleles more efficient than direct phenotype selection, as has been the case with
other traits of agronomic importance. Even though desirable traits are available among the breeding lines developed at VSU, it would be ideal to have F2 segregating populations, for QTL analysis of the current breeding lines and make crosses between genotypes with low and high nutritional values. The generated progenies would have to be advanced to subsequent several generations (RIL). However due to lack of expertise in biochemical analysis, the initial nutritional analysis of the current breeding lines is yet to be done. During the year, 40 selected breeding lines and germplasm accessions with high sucrose content have been identified and molecular characterization of these accessions is on going to identify the most genetic divergent lines for generating segregating populations.
Impacts
The current molecular breeding aspect of soybean is just in initial phase and thus no impact yet to report. Nevertheless, it is expected that improved vegetable soybean varieties will be adopted by farmers and consumers. This will definitely improved consumer's health and generate revenue for producers.
Publications
- No publications reported this period
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