Modifying Genes for Palmitate and Stearate Concentration Impacts Selection for Low‐Phytate, Low‐Saturate Soybean Lines

Abstract

ABSTRACTDevelopment of soybean [Glycine max (L.) Merr.] cultivars with low phytate (LP) and low saturated fatty esters (LS) would add value to both the meal and the oil. One of the challenges in breeding for the two traits has been the lack of LP parents with <70 g kg−1 palmitate plus stearate (saturate) concentration. The LP line A38 developed at Iowa State University was the first line identified with a saturate concentration <70 g kg−1 in multiple environments. The objective of our study was to determine if the LS in A38 was due to breakage of linkages between the lpa1 and lpa2 alleles and genes for elevated saturates that interacted epistatically or to the accumulation of favorable modifying genes for LS concentration. Three populations were made by crossing A38 to three LS cultivars with normal phytate (NP). The F2 plants were genotyped for the Lpa and lpa alleles, harvested individually, and evaluated for fatty ester composition. The mean saturate concentrations of the LP individuals were significantly greater than NP individuals. The frequency of LP lines with a saturate concentration ≤70 g kg−1 was greater than previously reported in populations in which LP parents had a saturate concentration >70 g kg−1. The LS concentration of A38 was attributed to favorable modifying genes for LS concentration. Use of LP and NP parent lines with a saturate concentration <70 g kg−1 would improve the frequency of LP, LS progeny.