Agronomic and Seed Characteristics of Soybean with Reduced Phytate and Palmitate

Abstract

Nonruminant animals fed soybean [Glycine max (L.) Merr.] meal cannot metabolize the P that is in the form of phytate. A soybean line CX1834-1-6 was developed that had a major reduction in phytate P and a concomitant increase in the inorganic P that is available to nonruminants. The objective of this study was to determine the impact of low phytate (LP) on agronomic and seed traits of lines with reduced palmitate in the seed oil. A population of soybean was developed by crossing CX1834-1-6 to a reduced-palmitate line B01769B019 and backcrossing the F1 plants to B01769B019. Twenty BC1F2–derived lines with LP and reduced palmitate and 20 lines with normal phytate (NP) and reduced palmitate from the population were evaluated at three Iowa environments in 2003. The LP lines had a mean seedling emergence that was 22.3 percentage units less than the NP lines. Although the plant density of the LP lines was less than the NP lines, the mean yield of the two types was not significantly different. The palmitate and stearate content of the LP lines was significantly greater than that of the reduced-palmitate parent. The reduced emergence and greater saturate content of the LP lines may make it difficult to develop acceptable cultivars for production of LP soybean meal and low-saturate oil.