小麦穗与小穗及籽粒差异的解剖结构和生理原因研究

目的]了解小麦穗、小穗及籽粒发育的不均衡性与维管束系统和有机养分在器官中的分配关系。方法]在小麦抽穗前,取主茎、一蘖和二蘖的穗下第1、第2节间,主茎穗的上、中、下不同部位的小穗作样品,测量维管束和韧皮部的面积,测定可溶性糖和氨基酸含量。结果]小麦穗下第1、第2节间直径、基本组织面积、维管束数目、维管束面积及韧皮部面积均以主茎为最大,一蘖次之,二蘖最小。穗中不同部位小穗的穗轴中的维管束分布有差异;同一小穗中通向各小花的维管束数目和面积也不同。在穗的发育过程中,植株及穗部器官中的可溶性糖和氨基酸的含量在不断变化,分配也不平衡。结论]小麦穗、小穗及籽粒发育的不均衡性和进入其中维管束分布的不平衡性密切相关。"源"与"库"的关系及维管束系统的共同作用导致了小麦各产量因素的不均衡发育。穗器官形成的不均衡性与养分供应差异有密切关系。

Research on the Relationship between the Development Imbalance of Wheat Ear, Spikelet and Grain and Vascular Brindle System and Its Physiolagical Reason

Objective] The study aimed to know the imbalance of wheat ear,spikelet and grain development,vascular bundle system and distribution relationship of organic nutrients in organs.Method] Before the heading of wheat,the 1st and 2nd internodes under ear were collected from the main stem,1st and 2nd tillers and the spikelet were collected from upper,middle and lower positions of ear on main stem to be used as samples to measure the areas of vascular bundle and phloem and determine the contents of soluble sugar and amino acid.Result] All the diameters of the 1st and 2nd internodes under ear of wheat,area of basic tissue,number and area of vascular bundle and area of phloem were biggest in main stem,that of the 1st tiller were secondary and that of the 2nd tiller were smallest.The distribution of vascular bundle in the rachises of spikelet in different parts of ear had difference,and the number and area of vascular bundle leading to each flowerlet was also different in the same spikelet.During the growth course of ear,the contents of soluble sugar and amino acid changed continuously with imbalance distribution in plant and organs in ear.Conclusion] The imbalance of wheat ear,spikelet and grain development closely related to the imbalance of the distribution of their vascular bundle.The interaction of source-sink relation and vascular bundle system led to imbalance development of each yield factor in wheat.The imbalance formed by ear organ had close relation with the difference of nutrient supplication.