桔梗(Platycodon grandiflorum A.DC)胚胎学研究——Ⅱ.大孢子发生、雌配子体发育、胚及胚乳发育

Embryonic Studies On Platycodon grandiflorum A. DC II -Megasporogenesis And Female Gametophyte, Embryo and Endosperm Developments

本文对桔梗(Platycodon grandiflarum A.DC)的大孢子发生、雌配子体发育、胚及胚乳发育进行了较为系统的研究。结果表明,大孢子母细胞经减数分裂形成四个线形捧列或T形排列的大孢子,合点端或珠孔端第三个大孢子具功能,雌配子体发育为蓼型;细胞型胚乳吸器为Codonopsis型。合子休眠期较长,大约在5～8天内进行分裂,胚为茄型。

The present paper studies megasporogenesis and female gametophyte, embryo and endosperm developments of Platycodon yi andiflorum A. DC. The main results were followings: 1, the megas-porocyte undergoes meiosis and gives a rise to a linear or a T-shaped tetrad of megaspore; the . chalazal megaspore or the third megaspore from the micropylar end was functional. The development of female gametophyte was of the poly gonum type. 2, the endosperm was cellular and the comporms was the codonopsis type. The resting period of the zygote was about 5 to 8 days. Thedevelopment of embryo was of the soiand type.