Maternal Effects for Fatty Acid Composition in Soybean Seed Oil.

Soybean (Glycine max (L.) Merr.) oil accounts for nearly half of the edible vegetable oil production worldwide.  The fatty acid composition of soybean seed oil affects its nutritional value and physical and chemical characteristics. In recent years, there has been an increasing demand to produce soybean oil products with altered fatty acid composition.  The success of developing soybean lines with genetically altered seed oil is greatly influenced by the rate of genetic gain through selection.  Maternal effects in plants can influence selection and reduce genetic gain.   The objectives of this study were to test for the presence and magnitude of maternal effects for fatty acid composition in soybeans across a wide range of genetic (nuclear and cytoplasmic) materials accross environments and to determine if maternal effects are maintained in vitro.  Maternal effects were evaluated in 2005, 2006, and 2007 by analyzing reciprocal F₁ seed resulting from crosses between the mid-oleic line N98-4445A and Dare, Haberlandt, Ogden, Arksoy, Midwest, and Peking and a cross between the elevated palmitic line N02-4441 and Dare.  Reciprocal F₁ seeds from a cross between N02-4441 and Dare along with the parents were grown in vitro.  The results showed that maternal effects for fatty acid composition were significant across a wide range of genetic materials in different environments.  These data suggest that single seed selection for altered fatty acid composition in early generations should be avoided and that single plant selection could be impacted by maternal effects if dominance is involved.  In addition, maternal effects between reciprocal crosses dissipated when grown in vitro, while significant differences between the parents were maintained.  This is evidence that factors translocated from the maternal plant shoot to the developing seeds may be causing the maternal effect.