通过对外源ＤＮＡ导入水稻第三代变异材料的部分器官的解剖观察，发现穗颈和第一节间的维管束数目及大小均较受体品种明显增加，维管束与茎壁组织的面积之比增大，剑叶中脉的维管束和气腔数目增多．这些结果说明变异材料的输导组织发达，物质转运畅通，单位时间内物质运输量多．从而为穗大粒多、早熟、结实率高提供了物质基础． Through the anatomical observation of some organs introduced from exogenous DNA into the third generation of rice, it was found that the number and size of vascular bundles in the neck and the first internode were significantly increased compared with the recipient, and the area ratio of the vascular bundle to the stem wall Increased, the number of vascular bundles and cavities in the veins of the flag leaf increased. These results show that the transduced tissue of mutated materials is well developed, the material transport is smooth, and the quantity of material transported per unit time is large. Thus for the spike large grain, precocious, high rate of seed provides a material basis.