雌雄异型异熟青钱柳花发育过程中养分的动态变化

Dynamic changes of nutrients during flora development in heterodichogamous Cyclocarya paliurus

【目的】青钱柳集药用、材用、观赏于一身,是典型的雌雄异型异熟植物,通过研究不同交配类型雌雄花芽(序)发育过程中花芽(序)和周围组织内养分的动态变化,以阐述其雌雄异熟的养分调控机理。【方法】在花发育期间,从青钱柳林分中随机选取两种交配类型(雄先型(简称PA),雌先型(简称PG)),观测花芽(序)(雄花♂,雌花♀)形态变化并测量花序长度;同时测定两种交配类型花芽(序)及其周围组织(雄花枝条(记为♂Z),雌花枝条(记为♀Z)和雌花叶片(记为♀Y))内的淀粉、可溶性糖和可溶性蛋白含量。【结果】(1)淀粉:花芽萌动前,花和枝条上均积累了大量淀粉,并随着花的发育呈持续下降的趋势;♂Z的含量显著高于♀Z,PA的♂Z上的含量高于PG的♂Z上的。(2)可溶性糖:萌动前♂Z积累了大量的可溶性糖,在发育过程中其含量呈现下降、上升并趋于稳定的动态过程,而♂内的含量出现波动但相对稳定;在♀及其周围组织均呈先上升后下降的趋势,在花序伸长生长结束时达到峰值。(3)可溶性蛋白质:萌动前PA的♂比PG积累了更多的可溶性蛋白,在两种交配类型♂上可溶性蛋白含量均随着花的发育逐渐下降,♂Z内的可溶性蛋白含量在发育过程中相对稳定;可溶性蛋白在♀花序开始伸长生长时达到高峰,而♀Y中的含量呈持续下降,♀Z上可溶性蛋白的变化模式在两种交配类型上存在差异。【结论】雌雄花发育所需可溶性糖主要来自自身和枝条内贮藏的可溶性糖和淀粉(水解产物),但PA的♂Z内贮藏的可溶性糖含量远高于PG的;雄花发育所需可溶性蛋白来自自身或光合产物的输入,雌花则主要来自光合产物的输入。淀粉和可溶性养分的动态变化在不同交配类型雌雄花上均存在时序差异,但与花序的发育进程一致。

【Objective】Cyclocarya paliurus is a typical heterodichogamous species. To demonstrate nutrient the regulatory mechanism of heterodichogamous characteristics of flowering in C. paliurus,dynamic changing patterns of nutrients in the flowers and surrounding tissues during various developmental stages of the floral were monitored. 【Method】In two mating types（ protandry,PA and protogyny,PG） of C. paliurus selected from a plantation,changes in morphology and length of male and female inflorescences（ male,♂; female,♀） were observed and measured; also,dynamic changes in starch,soluble sugar,and soluble protein content in the flowers and surrounding tissues（ branch surrounding male bud,♂Z; branch and leaves surrounding female bud,♀Z and♀Y） during the process of floral development were measured. 【Result】（1） Starch： much starch was found in the flower buds and branches before initiation,and the contents declined with the process of inflorescence development. The content of starch in♂Z was significantly higher than in♀Z,and the content in♂Z of PA was higher than that of PG.（2）Soluble sugar： large amounts of soluble sugar were found in♂Z before bud initiation and changing patterns of soluble sugar showed a dynamic pattern of＂declining to increasing,then a tendency to stabilize. ＂The content in the♂fluctuated with a little change,whereas the tendency of＂rising to declining＂and the maximum in the end of elongation growth of the ♀ occurred in the flower and surrounding tissues.（3） Soluble protein： more soluble protein was accumulated in the♂of PA than PG before bud initiation,and the content decreased gradually with floral development; whereas the content in♂Z changed a little. Soluble protein in the♀reached a peak before elongation growth of the inflorescence; whereas changing patterns of the content in♀ Y of PA were observed. However,changing patterns of the soluble protein content in♀Z were different between PA and PG. 【Conclusion】Soluble sugar for floral development was from soluble sugar and hydrolysis products of starch stored in flowers and surrounding the branch,whereas soluble sugar stored in♂ Z of PA was much higher than that of PG. Soluble protein stored in the♂or photosynthetic products input provided the needs for male flower development,whereas photosynthetic products were the only source for female flower development. Although changing patterns of starch and soluble nutrients are different in stages and sequences of male and female flowers between PA and PG,they were synchronized precisely with the process of floral development.