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Submitted to: Crop Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 10/19/2010 Publication Date: 3/14/2011 Citation: Bellaloui, N., Smith, J.R., Gillen, A.M., Ray, J.D. 2011. Effects of maturity genotypic background and temperature on seed mineral composition in near-isogenic soybean lines in the early soybean production system. Crop Science. 51:1161-1171. Interpretive Summary: Mineral content of soybean seed is one measure of seed quality. The effect of maturity on seed mineral content of soybean seed has not been well investigated because maturity and cultivar effects could not be separated (confounded). To separate the effect of maturity from the effect of cultivar on seed mineral (nitrogen, N; sulfur, S; calcium, Ca; potassium, K; magnesium, Mg; phosphorus, P; boron, B) concentrations, two sets of isolines were used and a field experiment was conducted in 2004 and 2005. Isolines are nearly 100% identical except for selected genetic regions. In this case, the lines differ in genes for maturity. Two sets of isolines were used. One set of isolines was derived from the cultivar Clark, and the other set from Harosoy. The results showed that as days to maturity increased, N and Ca seed concentration increased in the Clark isolines. For Harosoy isolines, similar trend was observed, but for Ca and B. Genotype (genotypic background) effect was highly significant for N, S, Ca, K, Mg, P, and B seed concentrations. Maturity genes (E-genes) effect was highly significant for Ca and B. The contribution of genotypic background and interactions of genotypic background, maturity, and temperature were greater for N, Ca, Mg, P, B, and Zn. The contribution of either maturity or temperature to total mineral concentration depended on the type of mineral. Results indicated that, depending on the type of mineral nutrient and year, the contribution of genotypic background or maturity on total variation of nutrient concentrations was greater than that of temperature in most cases. This information will help breeders for developing soybean germplasm with higher mineral seed content. Technical Abstract: Mineral content of soybean (Glycine max L. Merr.) seed is one measure of seed quality. The effect of maturity on seed mineral content of soybean seed has not been well investigated in the Early Soybean Production System because maturity is generally confounded with genotypic background effects. Therefore, the effects of maturity on seed mineral concentrations were investigated in two sets of near-isogenic soybean lines derived from either ‘Clark’ or ‘Harosoy’ genotypic backgrounds. For Clark isolines, there were significant (P=0.05) positive correlations between maturity and N and Ca (for N, r=0.83 in 2004 and r=0.62 in 2005; for Ca, r=0.59 in 2004 and r=0.89 in 2005). For Harosoy isolines, there were significant (P=0.05) positive correlations between maturity and Ca and B (for Ca, r=0.60 in 2004 and r=0.83 in 2005; for B, r=0.48 in 2004 and r=0.72 in 2005). Genotypic background effect was highly significant (P<0.001) for N, S, Ca, K, Mg, P, and B seed concentrations. Maturity gene (E-gene) effect was highly (P<0.0001) significant for Ca and B. Commonality analysis showed that the contribution of genotypic background and interactions of genotypic background, maturity, and temperature were greater for N, Ca, Mg, P, B, and Zn. The contribution of either maturity or temperature to total mineral concentration depended on the type of nutrient. Results indicated that, depending on the type of nutrient and year, the contribution of genotypic background or maturity on total variation of nutrient concentrations was greater than that of temperature in most cases. Maturity x genotypic background x temperature interactions also had a significant contribution, reflecting the significance of genotype x environment interactions for mineral nutrients. This information may be useful when developing soybean germplasm with higher mineral seed content. |
