半夏珠芽发育过程的形态学和解剖学研究

通过形态学观察和石蜡切片方法研究了半夏[Pinellia ternata(Thunb.)Breit.]的珠芽发育过程,结果显示:半夏珠芽着生于叶柄的下部,起始于幼嫩叶柄的腹面最外轮维管束外周薄壁细胞;恢复分裂的薄壁细胞分裂形成珠芽原基细胞团,在原基生长突破叶柄表皮后分化形成具有生长点的珠芽结构,发育中的珠芽无根分化;珠芽的生长被动地终止于叶片衰老(倒苗),无明显的成熟发育过程。研究表明,半夏的珠芽是不定芽性质的无性繁殖结构,但在发育过程上明显区别于其它植物的珠芽发育。

Morphological Observation and Anatomical Study on Bulbil Development of Pinellia ternata

Based on the morphological observation and anatomical study,we revealed the developmental characteristics of bulbil,which is the vegetative propagule of Banxia(Pinellia ternata).The bulbil of P.ternata was formed in the lower part of petiole.In young leaves,it was started from the parenchyma cells that located in the adaxial part near the outer ring of three-ring vascular bundle.Dedifferentiation cells divided continuously to form the primodia of bulbil.The primodia differentiated to form the shoot apical meristem(SAM) on the top and to form the infant bulbil after it grew enough to protrude the surface of petiole.There was not root formation for developing bulbil.Bulbil growth stopped because of leaf senescence naturally.Our results indicated that bulbil of P.ternata was vegetative progagule that resembles the adventitious bud.The development of bulbil in P.ternata was different from the formation of bulbils in other kinds of plant species.