14C-同化物在玉米果穗上的分布与籽粒败育关系

通过^14C-示踪方法，研究了在籽粒发育前期饲喂果穗叶后^14C-同化物在植株及果穗不同部位的分布。结果表明，果穗是灌浆期的主要库器官；^14C-同化物在果穗不同部位的分布不均一，在穗轴中^14C-同化物的分布呈现为基部〉中部〉上部，而在籽粒中则表现为中部〉基部〉上部。顶端穗轴中糖分含量不低于中部穗轴（P〉0．05），而败育粒中还原糖含量高于中部粒（P〈0．05）。因此认为，顶端的败育可能并非源于营养供应不足，而应归因于籽粒库活性不足。

Relationship between Distribution of 14C-assimilates and Kernel Abortion in Maize

The distribution of ~(14)C-assimilates in plant organs and different positions of ear in maize(Zea mays L.) was studied by feeding the ear leaf with ~(14)CO_2 at early period of kernel development.The results showed that ear was the main sink organ during kernel filling period,but the distribution of ~(14)C-assimilates was uneven in different parts of ear.The distribution of ~(14)C-assimilates in cob ranked as basal>middle>upper part,while the amount of ~(14)C-assimilates in kernel sequenced as middle>basal>upper part of the ear.The sugar concentration in upper cob was not less(P>0.05) than that in middle part,but the content of reducing sugar in aborted kernels was significantly higher(P<0.05) than that in kernels at middle part of ear.It suggests the main reason of kernel abortion at ear tip in maizewould be low sink strength in kernels instead of assimilate deficiency.