小麦穗部维管束系统及其与籽粒发育的关系

本文应用组织切片法研究麦穗维管束系统。结果如次:(1)穗下茎节横切面中,基本组织面积和中央维管束总面积对于产量的贡献大于茎内其他性状。小麦壮秆大穗的实质在于基本组织薄壁细胞的发达及维管束的总面积。(2)穗轴维管束的分布与前人结果不尽相同,我们发现中央维管束沿穗轴下降速度,因品种及施肥不同而有变化。(3)小穗内一二花维管束直接独立来源于小穗基部维管束结节,三花维管束除部分直接来源于基部结节外,与二花维管束的联系比一花密切,由此说明了长期未能解释的成熟时第二粒较重的原因。(4)穗轴及小穗轴上部维管束总面积下降较快。讨论了远端小穗及小花同化物运输的阻力及其改善的可能。

The Vascular System Within an Ear in Relation to the Development of Wheat Kernels

Tissue-cut section was used for a preliminary study on the vascular system within an ear in wheat.The results are shown that the cross-sectional areas of ground tissue and central vascular bundles in stem below an ear have more contribution to the yield of the ear than other character. And that the well developed.parenchyma in stem play an important part in strong and big ear. The number of central vascular bundles declined along the rachis with variable rate among the different varieties and among the fertilization treatment in the same variety. It is found that there is not direct vascular connection between first and second floret,but they are both connected more directly with the vascular node at the base of a spikelet, the third and the upper florets are associated more closely with the second floret than with the first within a spikelet.This is one of causes which the second grain is more heavy after maturing. The resistances of assimilate translation and the possibility of improving in the ends of an ear and in the upper florets of a spikelet were discussed.