温度对大豆(Glycine max)种子发育过程中蛋白质、脂肪和淀粉积累过程的影响

The effect of growth temperature on final protein and oil content of soybean (Glycine max L.) in seed fill has been studied. But it is unclear that how accumulation process of seed composition is in response to the temperature or whether different genotypes of soybean with high seed protein have similar responses to temperature in seed fill. The objective of this study was to investigate the developmental pattern of seed protein and oil accumulation under different temperature to know how the temperature affects the process of seed composition development. Three genotypes varying in final seed protein and oil content (Evans, PI 132.217, and Proto) were grown under optimal conditions (27/20℃, MT) in a growth chamber until 10 days after flowering (DAF) when pods at mid-stem nodes were fully expanded. Temperature in three growth chambers was then adjusted to one of three day/night temperature regimes: high temperature, 35/27℃ (HT); moderate temperature, 27/20℃ (MT), or low temperature, 20/12℃ (LT) and maintained until the seeds reached physiological maturity. Pods were collected every 3 days starting at 21 DAF at HT and MT, every 5 days starting at 25 DAF at LT to monitor changes in seed mass and composition. Seeds grown at HT matured sooner for all lines. At MT seed obtained greatest seed growth rate for all lines. At LT, seed growth rate was lower, and duration of growth became longer. Greatest oil concentration (%) was obtained at seeds reaching 60%-70% of final seed DW, then stabilized or decreased slightly as the seeds matured. The time for greatest oil concentration was advanced at HT, and delayed at LT. There was the same pattern of oil and protein accumulation on seed fill at LT. At HT and MT, oil and protein concentrations followed a similar pattern until 60% of final seed DW was reached and then the oil concentration stabilized or slightly decreased, protein concentration increased until mature. Higher temperature increased the rate of protein accumulation, particularly in the later stages of development, which was related to a rapid decrease in starch concentration. The developmental pattern of protein accumulation in three genetic lines was impacted by temperature. But the percentage of protein in higher protein lines of Proto (higher protein line) and PI132.217 (stable protein line) always was higher than that in low protein line of Evans. It suggested that character of genetic difference in accumulating protein in high protein line would be not altered by temperature. This study showed that genetic breeding plays a key role in increasing the seed with higher protein and higher oil. But it is also important in obtaining seed higher protein and oil concentration by choosing suitable planting dates.