施氮对半湿润农田生态系统不同冬小麦品种灌浆期物质转移的影响

在年均降水量632 mm的黄土高原南部半湿润红油土上,以NR9405、9430、偃师9号、小偃6号、陕229、西农2208、矮丰3号和商188为供试材料,进行大田试验,研究在不施氮和施氮(90 kg.hm-2)条件下不同品种冬小麦灌浆特性及物质转移效率。结果表明,冬小麦干物质生产及物质转移效率共同受品种和氮肥的影响。开花期老叶、茎鞘和成熟期茎鞘、籽粒干重间存在显著差异。施氮对开花期、成熟期地上部各部位干重均有明显的促进作用。各部位干物质转移量、转移效率和转移量对籽粒的贡献率既与品种有关,也与施氮有关;氮肥的影响又因品种不同而异。干物质转移量、转移效率和转移干物质对籽粒的贡献率在8个供试品种中,最高的是NR9405,最低的是偃师9号,除NR9405和西农2208籽粒中50%以上干物质来自于开花前贮存光合产物的再转移外,其余6个品种籽粒中50%以上的干物质来自于开花后新合成的同化产物。干物质转移量对籽粒的贡献率以穗轴+颖壳部位最低,且多数处理为负值,以茎秆为最大,叶片居中。从总体看,干物质转移量、干物质转移率和干物质转移量对粒重的贡献率在不同品种之间的差异大于施氮处理间的差异,施氮后降低了干物质向籽粒中的转移。

Effects of nitrogen fertilization on matter translocation of winter wheat cultivars at their grain-filling stage in sub-humid farmland ecosystem

A field experiment was carried out on the south Loess Plateau with an annual precipitation of 632 mm to study the effects of nitrogen fertilization on the matter translocation of winter wheat cultivars NR9405,9430,Yanshi No.9,Xiaoyan No.6,Shan 229,Xinong 2208,Aifeng No.3 and Sang 188 at their grain-filling stage.The results showed that there was no significant difference among different winter wheat cultivars in the dry matter production of green leaf,spike and stem at anthesis stage,and of leaf,hull and rachis at maturing stage,while a significant difference was observed in the dry matter production of old leaf and stem at anthesis stage,and of stem and grain at maturing stage.Nitrogen fertilization could significantly increase the dry matter production at anthesis and maturing stages.Among the test winter wheat cultivars,NR9405 had the highest dry matter translocation(DMT),dry matter translocation efficiency(DMTE),and dry matter translocation proportion for grain(DMTP),but Yanshi No.9 had the lowest ones.The DMT,DMTE and DMTP had a significant correlation with winter wheat cultivar and nitrogen fertilization.