Selection of High Inorganic Phosphorus-Low Stachyose Soybean Breeding Lines

Abstract

Soybean (Glycine max [L.] Merr.) seed stachyose and phytic acid are not digested by monogastric animals, and thus represent an obstacle for an efficient utilization of soybean meal in animal feed. The objectives of this research were to select breeding lines with high inorganic phosphorus (Pi)/low stachyose, along with adequate levels of sucrose, from an F_2:6 population derived from the cross S02-529 x V99-5089 and evaluate their yield potential and stability across environments. Sucrose distribution showed no distinctive pattern, whereas Pi and stachyose exhibited a bimodal distribution. Stachyose and Pi fit the expected 3:1 ratio for a one-gene model previously reported for the high-Pi/low-stachyose trait in V99-5089. The highest yielding line, R08-6023 (2894 kg ha⁻¹), showed relatively low stability for yield across environments, but it would be an adequate choice for highly productive environments. R08-6009 (2634 kg ha⁻¹) ranked fourth in yield but showed less yield fluctuations across environments than other lines studied. One selected line had moderately high oleic acid concentration (>45 mg g⁻¹), and three other lines had low linolenic acid concentration (<34 mg g⁻¹), which are unique combinations with the high-Pi/low-stachyose trait. Although relatively low in yield as compared to the commercial checks, these novel breeding lines would be useful in breeding programs in developing multiple-trait stacks of value when incorporated into high-yielding backgrounds.

Acknowledgments

We thank the staff of the University of Arkansas Soybean Breeding Program for their help with field and laboratory work. We also thank Miguel A. Jaureguy for his help with processing of seed samples for protein, oil, and fatty acid analysis. The research presented in this paper is part of LMJ PhD dissertation, and partially supported by the United Soybean Board and the Arkansas Soybean Promotion Board.