山核桃雌花发育的解剖学研究

Studies on Anatomy of Development of Female Flower in Carya cathayensis Sarg.

为掌握山核桃(Carya cathayensis)雌花花芽分化规律,从超微结构、显微结构和外部形态变化多个层次上综合研究雌花发育过程。结果表明,雌花发育过程从3月下旬开始到5月中旬基本完成,历时约35 d,整个过程可分为未分化期、分化初期、花序分化期、总苞形成期和雌蕊形成期共5个时期。未分化期雌花芽外部形态与叶芽无区别;分化初期生长点趋于半圆形;花序分化期3个小花原基形成;总苞形成期每一小花周围形成1个总苞片和3个小苞片;雌蕊形成期小花继续发育,胚囊形成。

To understand the law of flower-bud differentiation in Carya c development of female flower was studied comprehensively in its ultrastructure, athayensis sarg. ,the microstructure and macrostructure. Differentiation of female flower begins generally from the last 10 days in March, till the second 10 days in May when the flower＇s development is basically completed. The whole process needs about 35 days totally. The whole process can be divided into 5 stages, the undifferentiated stage ,the initial stage of flower bud differentiation and the stage of formation and development of the inflorescence, of the female involucre, and of the pistil. At the first stage,the exterior appearance of pistillate flower bud has no differentiation with leaf bud. At the second stage, the top tends to take the shape of hemisphere, the exterior appearance has no variety. At the third stage three flower primordia are formed. As to the exterior appearance, the flower bud is ambiguous, therefore, every tiny flower forms a total husk and three small husks around, at the fourth stage the floret is already obvious. Therefore, at the last stage the tiny flower and ovule embryo sac begin to develop.