花后干旱与渍水下氮素供应对小麦碳氮运转的影响

防雨池栽条件下，设置渍水、干旱和对照3个土壤水分处理，每个水分处理下再设置两个施氮水平，研究了花后渍水和干旱逆境下氮素水平对两个蛋白质含量不同的小麦品种碳氮运转的影响。结果表明，与对照相比，花后渍水和干旱处理均降低小麦叶、茎鞘、颖壳等各营养器官花前贮藏物质再运转量和再运转率以及营养器官花前贮藏物质总运转量，降低了籽粒重。水分逆境下增施氮肥可以提高小麦叶和颖壳花前贮藏物质再运转量和运转率，茎鞘花前贮藏物质再运转量和运转率。在对照和干旱下增施氮肥提高了营养器官花前贮藏物质总运转量和运转率以及籽粒重和花后同化物输入籽粒量，而渍水下增施氮肥趋势相反。水分逆境降低了小麦叶、茎鞘、颖壳等各营养器官花前贮藏氮素再运转量和再运转率以及花前贮藏氮素总运转量和总运转率，降低了小麦籽粒氮积累量。在对照和干旱下增施氮肥提高了小麦叶片的花前贮藏氮素运转量和运转率，茎鞘的贮藏氮素运转量，营养器官花前贮藏氮素总运转量和运转率，籽粒氮积累量以及花前氮素对籽粒总氮贡献率，而渍水下增施氮肥趋势相反。水分逆境明显降低小麦产量、淀粉和蛋白质产量，且干旱处理下增施氮肥有利于籽粒产量、淀粉产量和蛋白质含量的提高，而渍水下增施氮肥使产量进一步降低。试验结果表明，花后渍水和干旱逆境下施用氮肥可明显调节小麦碳、氮物质运转以及最终的籽粒淀粉与蛋白质积累。

Effects of Nitrogen Rates on Carbon and Nitrogen Assimilate Translocation in Wheat Grown under Drought and Waterlogging from Anthesis to Maturity

Effects of nitrogen rates on carbon and nitrogen assimilate translocation in two different wheat varieties under soil drought and waterlogging from anthesis to maturity were investigated in a cement pool culture experiment. Three water treatments were established from anthesis to maturity, i.e. waterlogging, drought and moderate water supply (CK), and under each water treatment, two nitrogen levels of 120 and 240 kg/hm~2 were implemented. Compared with CK, drought and waterlogging reduced the amounts and remobilization rate of pre-anthesis stored assimilates, total amount of pre-anthesis stored assimilate and grain weight. Under drought and waterlogging, nitrogen increased amounts and remobilization rate of pre-anthesis stored assimilates in leaves, hull and rachis, stem and sheathes. Under CK and drought nitrogen increased total amounts and remobilization rate of pre-anthesis stored assimilates, grain weight and the amounts of pre-anthesis assimilates transferred into grains, while nitrogen reduced them under waterlogging. Both drought and waterlogging reduced the amounts and remobilization rate of pre-anthesis stored nitrogen and nitrogen accumulation in grains. Under drought and waterlogging nitrogen increased amounts and remobilization rate of pre-anthesis stored nitrogen in leaves, amounts of pre-anthesis stored nitrogen in stem and sheathes, total amount and remobilization rate of pre-anthesis stored nitrogen, nitrogen accumulation in grains and the translocation of pre-anthesis accumulated nitrogen into grains, while under waterlogging nitrogen reduced them. Both drought and waterlogging reduced grain yield, starch and protein yield. Nitrogen favored grain yield, starch yield and protein content under drought, but reduced grain yield under waterlogging. The results indicated that nitrogen regulated translocation of carbon and nitrogen assimilate and sequentially regulated accumulation of grain starch and protein in wheat grown under stress conditions of soil drought or waterlogging from anthesis to maturity.