水稻小穗轴维管系统网络结构探讨

Study on the constructure of vascular network of a rachilla in rice ( Oryza sativa L.)

对籼型、粳型或其不育系与保持系代表品种小穗解剖观察表明：水稻小穗轴维管系统网络由中央维管束和各分枝维管束复合而成。来自小穗柄的１条大的中央主束和几条边围维管束经数次分枝、联结，不断产生新的分枝维管束进入相应的结构。一般颖片中维管束１－２条，第一稃片中１－３条，第二稃片中１－４条，第二朵退化小花残余结构中０－３条，顶生可孕小花的外稃中５条，内稃中３条，浆片中各２条，雄蕊中各１条，雌蕊中３条，主束与支束既相互独立又联系，其粗细、形状、走向不断地改变着，它们共同制约着花器官各部分结构的发育，影响着小花的开闭与结构。此外，讨论了小穗轴维管网络节的分布，以及相关维管束中木质部和韧皮部的特征。

Varcular networks in the rachilla of indica and japonica subsipecies were observed respectively.The results were as follows:the network consisted of a large VB (vascular bundle) in centre and a few small VBs (twigged VB) in a rachilla.Both they could develop many different branches,going through into the relative constructures of a spikelet respectively.There were 1-2 VBs in a glume (2-4 VB in two glumes),1-3VBs in a first lemma,1-4 VBs in a second lemma,and 5 VBs in the lemma,3 VBs in the palea,2 VBs in a lodicule,1 VBs in a stamen and 3 VBs in the pistil in the uppermost floret respectively.The morphology and rendency of the centrary and their brahches in a spikelet could be in changing a any time,and together they controled the pattern of constructure developing,flowering and fruiting of a floret.