薄壳山核桃雌花发育的解剖学研究

为掌握薄壳山核桃(Carya illinoinensis)雌花花芽发育规律,应用了石蜡切片技术,从显微水平上对浙江省建德市12年生薄壳山核桃花芽发育各阶段特征进行观察,结果表明:薄壳山核桃马罕(Mahan)雌花发育过程可分为4个时期,分别是分化初期、花序分化期、雌花总苞形成期和雌蕊形成和发育期,在分化初期雌花芽与叶芽无区别,顶端呈圆球状;花序分化期形成两个以上椭圆状小花原基;雌花总苞形成期总苞略呈四方形,中央部位形成雌蕊原基并进一步分化出胚珠原基;雌蕊形成和发育期胚珠继续发育,胚囊形成.准确确定薄壳山核桃马罕雌花发育各个关键时期可为合理品种配置及人工授粉提供依据.

A Study on Anatomy of Development of Female Flower in Carya illinoinensis

Accurate determination of the critical stages of flower-bud differentiation is necessary for proper variety allocation and manual pollination of pecan (Carya illinoinensis). In a study reported herein, the paraffin-sectioning method was employed to observe, under a microscope, the development process of flower-bud differentiation in a 12-year-old pecan tree in Jiande city of Zhejiang province so as to solve the problem of its low yield and inferior quality. The results showed that development process of the female bud of the pecan variety Mahan could be divided into four stages, i.e. the initial differentiation stage, the stage of inflorescence formation and development, the stage of involucre formation and the stage of pistil formation and development. At the first stage, the exterior appearance of the pistillate flower bud was no different from that of the leaf bud, and their top was sphere-like in shape. At the second stage, two or more oblong floret primordia were formed. At the third stage, a square-shaped involucre was formed, and at the center of the involucre a pistil primordium was detected, from which an ovule primordium was differentiated. At the fourth stage, the ovule continued to develop and, eventually, the embryo sac was formed.