Abstract:

Quality of oil determined by the constituents and proportion of fatty acid components, and the understanding of heredity of fatty acid components is of importance to breeding for good quality soybean varieties. Embryo, cytoplasmic and maternal effects and genotype×environment interaction effects for quality traits of soybean （G. max Merill）seeds were analyzed using a general genetic model for quantitative traits of seeds with parents，F₁ and F₂ of 20 crosses from a diallel mating design of 5 parents planted in the field in 2003 and 2004 in Harbin, China. The interaction effects of palmitic, stearic and linoleic acids contents were larger than genetic main effects，while genetic main effects were equal to interaction effects for linolenic and oleic acids content. Among all kinds of genetic main effects，the embryo effects were the largest for palmitic，stearic and linoleic acids，and cytoplasm effects were the largest for oleic and linolenic acids. Among all kinds of interaction effects，the embryo interaction effects were the largest for fatty acids. The sum of additive and additive×environment effects were larger than that of dominance and dominance×environment effects for linolenic acids content, but not for other quality traits. The general heritabilities were the main parts of heritabilities for palmitic acids content and oleic acids content，but the interaction were more important for stearic, linoleic and linolenic acids contents. For the general heritability, maternal and cytoplasm heritabilities were the main components for palmitic, oleic and linolenic acids contenst. It was shown for the interaction heritabilities that embryo interaction heritabilities were more important for oleic and linolenic acids contents，while maternal interaction heritabilities were more important for linoleic acids content. Among selection response components，maternal and cytoplasm general responses and/or interaction responses were more important for palmitic, stearic, oleic and linoleic acids contents. The main selection response components were from embryo general response and/or interaction response for linolenic acid content. It suggested that the selection of palmitic, stearic, oleic and linoleic acids contents in offspring should be in maternal plants，while linolenic acids content should be improved screening the single seed or selected in higher generations.

Key words: Soybean, Fatty acids, Embryo effects, Cytoplasmic effects, Maternal effects, Heritability