番木瓜体胚间接发生方式的研究

Studies of Indirect Somatic Embryogenesis of Papaya

为了建立小果型番木瓜(Caricapapaya L.)高效外源基因遗传转化体系,以小果型番木瓜‘美中红’的幼胚(授粉受精后90～120d)为材料,通过组织切片和电镜观察体胚发生方式。结果表明,培养8～12d,愈伤组织首先发生于幼胚的胚根端;培养26d,整个幼胚的胚轴愈伤化,愈伤组织分为粘性透明和干性两大类,组织切片分为明显的两层,外层疏松易脱落,内层结构紧密;培养38d,淡黄色的体胚前体发生于幼胚的胚芽端。番木瓜体胚的形态各异,大多数是形态正常的体胚,少数体胚的形态发生变异。

In order to establish genetic transformation system of foreign genes on small fruit type of papaya, indirect somatic embryogenesis of immature embryos （90 - 120 days after pollination） of Carica papaya L. ‘Meizhonghong＇ was studied by histological section and observation with a scanning electron microscope. The results showed that the calli were originated from the epidemic cells of the radicle after 8 - 12 days of culture. After 26 days of culture, the whole embryonary axis turned into calli which differentiated to translucent and mucous, and dry types. The cross-section results showed the calli consisted of two distinct sectors, a loose friable tissue of outer sectors and compact aggregates of inter sectors. Yellow pre-embryonic complexes were derived from calli of the plumula after 38 days of culture. It was observed that most of the morphological somatic embryos were normally developed.