Maternal Control of Oil Synthesis in Soybeans, Glycine max (L.) Merr. 1

Seeds of F 1 , F 2 , and backcross populations resulting from crosses between high oil (21‐22%) and low oil (13‐16%) soybean Glycine max (L.) Merr., lines were analyzed NMR for oil content both on an individual seed and on an individual plant basis. On the average, oil content of F 1 seeds was 1.1% lower than the oil contents of seeds resulting from self‐fertilization of the high line female parents and 1.3% higher than that from the low line females. Heritability estimates based on single seed values were negligible and the correlation between oil content of F 2 seeds and F 3 seeds on the resulting F 2 plants was +0.25. On a plant basis the oil content of F 1 plants was intermediate between the oil contents of seeds produced by self fertilization on the two parents. About 60% of the total variability among F 2 plants was due to additive genetic effects. No cytoplasmic effect was detected. It was concluded that oil synthesis in soybean seed is determined largely by the genotype of the plant producing the seed. Thus, selection for oil contents among individual seeds on the same plant likely will be ineffective even though the plant is heterozygous for genes affecting oil content.