Submitted to: Crop Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/27/2000
Publication Date: N/A
Citation: Interpretive Summary: Soybean is the world's major source of plant protein and produces multi-billion dollar crops in the U.S. each year. Increasing protein content of the seed would greatly increase the value of the crop. Wild soybean has higher protein levels than soybean cultivars. In this study the authors demonstrated that a gene for higher protein from wild soybeans could be 'tagged' with molecular markers. They showed that breeders can now use these molecular markers to select for increased protein in their breeding programs. Now breeders can breed soybeans with higher protein by using marker facilitated selection which should increase the speed in which improved soybean can be created.
Technical Abstract: Increases in the seed protein concentration of soybean [Glycine max (L> Merr.] would increase the value of the crop. Two major quantitative trait locus (QTL) alleles from Glycine soja Sieb. and Zucc. that increased seed protein concentration were identified previously. The first objective of our study was to test the two G. soja QTL alleles in a population developed dthrough backcrossing the alleles into a soybean background. The second objective was to evaluate the effect of one of the G. soja QTL alleles in three genetic backgrounds. A backcross three (BC3) population was developed and evaluated in the field across two locations over two years. To test the allele in different backgrounds, a line from the backcross population was crossed to three soybean genotypes. Populations developed from these crosses were then evaluated in three field environments. In the backcross population, genetic marker alleles linked to the QTL allele from G. soja on linkage group (LG) I were significantly associated with greater protein and less oil concentration, reduced yield, smaller seeds, taller plants, and earlier maturity than the G. max alleles. Markers linked to the second G. soja QTL allele on LG E were not significantly associated with the seed or agronomic traits. In the genetic background tests, markers linked to the G. soja QTL allele on LG I were associated with an increase in protein concentration in two of the three crosses. These results show that seed component traits can be successfully modified through genetic mapping coupled with marker assisted selection.