朴树的受精作用及胚、胚乳的发育

本文对朴树(Celtis sinensis Pers.)的受精作用及胚与胚乳的发育进行了一些观察,主要结果如下:1.朴树花杂性,具两性花及雄花,两性花中雌雄蕊异熟,因而保证了同株异花传粉,珠孔受精。2.双受精过程属有丝分裂前配子融合类型。授粉后10d左右,雌、雄性核发生融合,精核与极核或次生核←的融合早于精核与印核的融合。3.初生胚乳核休眠10d后发生第一次有丝分裂,合子休眠20d后才进行第一次分裂。合子在休眠过程中极性发生逆转。4.核型胚乳。胚乳具约200个游离核时以自由生长的细胞壁的方式细胞化。茄型胚胎发育。胚乳在胚的发育过程中被吸收消失。

FERTILIZATION AND DEVELOPMENT OF EMBRYO AND ENDOSPERM IN CELTIS SINENSIS PERS

Fertilization and development of embryo and endosperm in Celtis sinensis Pers. Were systematically studied in this paper. The main results were as follows: 1. There are two kinds of flowers in this plant--bisexual flowers and male flowers. In bisexual flower, the machanism to prevent self-pollination is dichogamy (protogyny). Porogamy. 2. The dou- ble fertilization refers to the type of premitotic syngamy. Most of the female and male nuclei fuse each other in 10 days after pollination. The formation of primary endosperm nucleus is ealier than that of the zygote. 3. The primary endosperm nucleus begins its first mitosis after 10-day dormancy. The zygote always has 20-day dormancy before mitosis and converts its polarity during dormancy. 4. The development of endosperm belongs to the nuclear type. The endosperm cells start to form by the way of free growing wall when there are about 200 nuclei. The development of embryo belongs to solanad type. Endosperm disappears during the late development of embryo.