[Objective] The paper aims to explore the influences of source sink change of wheat at different densities on wheat yield.[Method] 225 (D1) and 320 plant/m2(D2) were adopted,then cutting flag leaf (L1),the second last leaf (L2),removing upper part of spike (L3) and controlling (CK) were used to conduct field experiment.[Result] The results showed that both of the two densities of wheat's 1 000-grain weight and grain filling rate after anthesis in a decreasing order of L3〉CK〉L2〉L1,and the grain weight per spike and dry matter amount translated after anthesis turned to be CK〉L2〉L1 〉L3.[Conclusion].Both of leaf-cutting and spikelet removing decreased the grain weight per spike and dry matter amount translated after anthesis.Removing upper part of spike increased wheat's 1 000-grain weight.But the decreasing of the sink and dry matter amount translated contributed to the decreasing of the yield of wheat.
通过田间模拟UV-B辐射增强,并采用FieldSpec Pro FR光谱仪进行田间观测,对UV-B辐射增强20%(U)条件下免耕(Z)和深耕(C)两种耕作方式对冬小麦冠层反射光谱和一阶导数光谱的影响进行研究,试验以无UV-B辐射增强(N)为对照,共设4个处理,分别为ZU、ZN、CN、CU。结果表明,冬小麦冠层光谱能有效监测UV-B辐射增强和两种耕作方式的复合作用。各处理间小麦冠层反射光谱的差异主要体现在近红外高台,灌浆期是最佳监测生育期。在灌浆期,U处理导致小麦冠层光谱近红外高台反射率明显降低,Z处理的近红外高台反射率明显低于C处理,且其受U处理的影响小于C处理,表明免耕具有延缓叶片衰老的作用。进一步采用一阶导数光谱分析发现,各处理在开花期和灌浆期均有显著差异。U处理导致红峰高度在灌浆期显著降低。Z处理的红峰高度明显低于C处理,红边位置比C处理偏红,并出现多峰情况。在未来UV-B辐射增强情景下,研究结果可为不同耕作方式下冬小麦采用冠层光谱进行无损检测的可行性提供理论参考。