摘要
【目的】本研究通过种子快速生长期对3个不同基因型大豆(Evans-低蛋白品种;PI132.217-高蛋白稳定品种;Proto-高蛋白品种)供氮以了解供氮是否能提高种子蛋白质含量并改变种子组分,为大豆合理施氮和育种提供参考。【方法】采用液体组培法,即在植株开花后第18天,采集体积相同的种子,将子叶培养在含氮量不同的营养液中(0、37、75和150mmol·L-1谷氨酰胺)。在植株开花后的第24,30,36和42天以及在液体组培的第6,12,18和24天,分别收集种子和子叶测定干重(DW)和种子组分。【结果】供氮条件下种子鲜重(FW)和干重的积累速率明显比在植株上快。与植株上种子相比,Evans和Proto在供给37mmol·L-1谷氨酰胺时种子生长迅速,蛋白质-N积累量较高;供氮量超过75mmol·L-1种子中积累较多的非蛋白-N,脂肪积累量下降。PI132.217在供氮条件下种子生长速率和蛋白质含量均未增加,供氮量超过37mmol·L-1种子脂肪和淀粉含量下降。3个基因型大豆植株供氮能力存在差异,PI132.217植株供氮能力较高(约40mmol·L-1谷氨酰胺),而Evans和Proto植株供氮力较低(约20mmol·L-1谷氨酰胺),所以种子生长和蛋白质积累对供氮反应敏感。【结论】由于大豆植株供氮量不足,所以供氮可明显使低蛋白质品种种子蛋白质含量提高,但过量供氮可能因种子细胞中C源不足和N利用率低而限制种子生长和蛋白质积累。不同基因型品种在供氮量和氮利用率上存在遗传差异,通过遗传育种进行基因改良,提高种子的供氮能力和氮代谢能力可能是提高大豆种子蛋白质含量的重要途径。
[Objective] This study was to test whether amino-N supply during rapid seed filling could stimulate seed protein accumulation without a negative impact on the accumulation of other valuable seed components. [Method] The seeds of three genotypes （Evans, PI132.217, and Proto） with various seeds protein contents were grown under optimal conditions in a growth chamber until 18 days after flowering. Then the seeds collected from plant in the middle node of plant, the cotyledons were cultured in liquid medium with different concentrations of glutamine （0, 37, 75, 150 mmol·L^-1）. The seed and cotyledon were harvested respectively in the day after flower （DAF） of 24, 30, 36 and 42 in vivo and 6 d, 12 d, 18 d and 24 d in vitro. [Result] The accumulated rate of cotyledon FW and DW in vitro was more rapidly than those in plant. Under supplying amino-N at 37mmol·L^-1 or over, Evans and Proto cotyledons grew more rapidly and accumulated more protein N. At amino-N concentration above 75 mmol·L^-1, Evans and Proto accumulated more non-protein-N, decreased oil accumulation. But there was no response to supplying amino-N in PI132.217 cotyledons. While supplying amino N at 37 mmol·L^-1 glutamine decreased oil and starch accumulation. There was a difference in supplying N for seed development in planta among three genetic lines of soybean. In planta, Evans and Proto can not provide seeds with demanded N, they were very sensitive to supplying N. But PI132.217 can get enough demanded N from planta, it was not response to supplying N. [ Conclusion ] Increasing N supply from the plant could lead to a modest increase in seed protein content in low protein genotypes. Then, over supplying N will negatively impact on metabolism of available C into oil and starch. Because there is a genetic difference in N-supplying and N utilization in genetic lines of soybean, genetic breeding may be a good way for improving N-supplying and ability of N metabolism to enhance protein content of seed.
出处
《中国农业科学》
CAS
CSCD
北大核心
2008年第10期3033-3041,共9页
Scientia Agricultura Sinica
基金
鲁东大学校基金
中科院方向性项目(KZCX2-YW-431)
关键词
基因型
种子组分
氨基氮供氮
组培
大豆
Genotypes
Seed composition
Amino-N supply
Tissue culture
Soybean
