对小麦顶生小穗的初步研究

1.顶生小穗的护颖具有特殊的形态,第二护颖常为小花外稃状,腋内有时还保留着雌雄蕊或内稃残余。说明其不稳定和可变的本质。2.顶生小穗具特殊的坐落位置,其小穗轴与主穗轴一致。顶生小穗原始体发生在穗生长锥顶端,其下无苞原始体,长成后也无小穗领。其护颖和小花外稃与侧生小穗下的小穗领呈严格连续互生状态。说明其一次轴的渊源。3.顶生小穗护颖腋内可长出小穗,小花也可代之以小穗,护颖和小花外稃有时以苞片的形式保留于新侧生小穗外侧。新顶生小穗的护颖来自小花外稃。说明顶生小穗护颖腋内的退化花芽、外稃腋内的小花与侧生小穗都是花序一次轴上的二次轴分枝。4.顶生小穗产生小穗的变异严格按自下而上的顺序进行,与原侧生小穗有严格的连续性。5.事实证明,顶生小穗是一次轴花序,它属于穗状花序顶端的可变部分。

THE PRELIMINARY RESEARCH ON THE TERMINAL SPIKELET OF WHEAT

1. The glumes of the terminal spikelet have peculiar forms. The second glume and lemma are often similar in form, but sometimes there are some remainders of stamen or palea in the axil of it. Thus it can be seen that the terminal spikelet is unstable and variable. 2. The two glumes of the terminal spikelet are parallel to the flat sides of the rachis. The terminal spikelet occur at the apex of rachis, is not in the axil of the original body of bracteal leaf. There is not small collar under it. The glumes and floret's lemmas of the terminal spikelet are parallel to the leteral spikelets and the small collars. The results show clearly that the terminal spikelet is the first axial spikelet. 3. Under given conditions, the new leteral spikelets can grow up from the axils of the glumes and floret's lemmas of the terminal spikelet. The glumes and lemmas are sometimes remained outside of the new leteral spikelets. Therefore, the degenerative florets in the axils of the glumes and the florets in the axils of the lemmas of the terminal spikelet as well as the leteral spikelets are all the second axial branches. 4. The variations of the terminal spikelet are from bottom to top. There is not a line of demarcation between the new perellal spikelets and the below perellal spikelets. 5. The facts fully prove that the terminal spikelet is the first axial inflorescence. It is the variable part of spike top.