Research notes: Soybean linkage tests between two seed proteins and other characters

F2 linkage results between Ti and W1, Dt1 and EP are shown in Table 1. F2 linkage results between SP1 and W1, Dt1, EP and Le are shown in Table 2. In all cases the Chi-square values were calculated using contingency tables

Research notes: Screening the USDA soybean gennplasm collection for Sp1 variants.

Orf and Hymowitz (1976) using polyacrylamide gel electrophoresis revealed that the seed protein band called A by Larsen and Caldwell (1968) occurs at Rf 0.36 and the seed protein band called B occurs at Rf 0.42 (Rf= mobility relative to a bromophenol blue dye front in a 10% polyacrylamide gel anodic system using a pH 8.3 Tris-glycine buffer). The inheritance of these proteins (although the proteins were not characterized) was reported as being controlled by two codominant alleles at a single locus (Larsen and Caldwell, 1968). Orf and Hymowitz (1976) proposed the gene symbols Sp1a and Sp1b for the electrophoretic forms that occur at Rf 0.36 and Rf 0.42, respectively

Row Widths for Full Season Soybeans in Kentucky

Soybean yields in Kentucky have increased steadily in the past 20 years as a result of improved varieties and production practices. To achieve even higher yields new varieties and better production practices need to be developed and tested. One possibility for increasing soybean yields is to plant in narrow rows using varieties which respond to this practice. Although previous research in Kentucky has not shown a yield advantage for full season soybeans planted in narrow rows, researchers in other states have recently shown increases in yield with narrowing row widths. A number of new varieties have also been developed specifically for narrow row plantings. These varieties are shorter, lodge less, and have a high yield potential. This study was designed to answer the question: Will narrow row widths provide higher yields for these soybean varieties when grown under full season conditions in Kentucky

QTL for seed protein and amino acids in the Benning × Danbaekkong soybean population

Soybean, rather than nitrogen-containing forages, is the primary source of quality protein in feed formulations for domestic swine, poultry, and dairy industries. As a sole dietary source of protein, soybean is deficient in the amino acids lysine (Lys), threonine (Thr), methionine (Met), and cysteine (Cys). Increasing these amino acids would benefit the feed industry. The objective of the present study was to identify quantitative trait loci (QTL) associated with crude protein (cp) and amino acids in the ‘Benning’ × ‘Danbaekkong’ population. The population was grown in five southern USA environments. Amino acid concentrations as a fraction of cp (Lys/cp, Thr/cp, Met/cp, Cys/cp, and Met + Cys/cp) were determined by near-infrared reflectance spectroscopy. Four QTL associated with the variation in crude protein were detected on chromosomes (Chr) 14, 15, 17, and 20, of which, a QTL on Chr 20 explained 55 % of the phenotypic variation. In the same chromosomal region, QTL for Lys/cp, Thr/cp, Met/cp, Cys/cp and Met + Cys/cp were detected. At these QTL, the Danbaekkong allele resulted in reduced levels of these amino acids and increased protein concentration. Two additional QTL for Lys/cp were detected on Chr 08 and 20, and three QTL for Thr/cp on Chr 01, 09, and 17. Three QTL were identified on Chr 06, 09 and 10 for Met/cp, and one QTL was found for Cys/cp on Chr 10. The study provides information concerning the relationship between crude protein and levels of essential amino acids and may allow for the improvement of these traits in soybean using marker-assisted selection