施氮时期对专用小麦干物质和氮素积累、运转及产量和蛋白质含量的影响

为了明确施氮时期对小麦花后干物质和氮素积累与运转的影响及其与产量和品质的关系，在大田高产条件下，研究了不同追氮时期对二个专用小麦品种开花前后氮素同化、运转和蛋白质含量的影响。结果表明，拔节和孕穗期追氮均提高了小麦产量和籽粒蛋白质含量，但过迟追氮不利于产量和蛋白质含量的同步提高。不同追氮处理显著提高了徐麦26花后氮素积累量，降低了营养器官贮存氮素向籽粒的转运，但提高了淮麦18营养器官贮存氮素向籽粒的转运。相关分析表明，徐麦26籽粒蛋白质合成所需氮素主要来源于花后氮素同化，而淮麦18则更多地依赖于开花前贮存氨素的再动员与分配。

Effect of Nitrogen Topdressing Time on the Accumulation and Transfer of Nitrogen,Yield and Protein Content in Specialty Wheat

A field experiments was carried out to investigate the effects of nitrogen topdressing time on the (nitrogen) accumulation and transfer, grain yield and protein content of two specialty wheat cultivars, Xumai 26 and Huaimai 18 under high yield conditions. The results showed that the nitrogen topdressing at jointing and (booting) stages increased the grain yield and protein content but the topdressing at heading and flowering stages might be unfavorable to simultaneously increase the yield and protein content. Compared with the (no-topdressing) treatment, the topdressing treatments significantly increased (post-anthesis) (nitrogen) (assimilation) of Xumai 26, decreased the transfer of reserved nitrogen in vegetative organs to the grain but increased that in Huaimai 18. The correlation analysis showed that grain protein content of Xumai 26 was significantly correlated with the post-anthesis nitrogen assimilation, However the grain protein content of Huaimai 18 was significantly correlated with the transfer of reserved (nitrogen) in vegetative organs. The results indicated that different (nitrogen) topdressing time should be adopted in promoting the grain protein content for different specialty wheat (cultivars).