摘要
利用石蜡切片技术对百合科植物黄花油点草[Tricyrtis maculata(D.Don)Machride]双受精、胚及胚乳发育进行了研究,以明确其胚胎发育的特征,为百合科植物的系统研究提供生殖生物学资料。结果表明:(1)黄花油点草为珠孔受精;进入胚囊的2枚精子分别与卵细胞和中央细胞进行正常的双受精,其受精作用属有丝分裂前型。(2)受精后的初生胚乳核立即分裂,其发育方式为核型胚乳;早期的游离胚乳核沿胚囊的边缘分布,胚囊中央部位主要为胚乳细胞质,随着游离胚乳核数量的增加,胚乳核慢慢充满整个胚囊;当发育至球形胚早期阶段,在各胚乳核周围产生胚乳细胞壁,形成完整的胚乳细胞。(3)合子有较长的休眠时间,胚的发育方式为茄型;合子第一次有丝分裂为横裂,分裂后形成基细胞和顶细胞;基细胞经过3次横裂,形成一列胚柄细胞;顶细胞经过分裂形成胚体,依次形成球形胚、棒状胚和盾形胚。(4)种子成熟时胚无器官分化;成熟种子由种皮、胚和胚乳三部分组成。
Some investigations on the processes of double fertilization,embryogenesis and endosperm development in Tricyrtis maculata （D.Don） Machride have been observed by the method of paraffin sections.The main results as follows：（1）The fertilization is of porogamy type.Two sperms entered the embryo sac fertilized the egg and central cell and the syngamy belongs to premitotic.（2）The development of endosperm is of the Nuclear type.The division of the primary endosperm nucleus and a few subsequent divisions are not accompanied by wall formation.Endosperm nuclei begin to become celled with the formation of the free cell wall at the globular proembryo.（3）The zygote has a longer period of dormancy and slower rate of development than the endosperm.The embryogeny corresponds to the Solanad type.The zygote divides transversely and gives rise to a 2-celled proembryo including a basal cell（CB） and a terminal cell（CA）.Before long,both of the CB and CA in 2-celled proembryo divide transversely and give rise to a linear 4-celled proembryo.The two basal cells of the 4-celled proembryo undergo further divisions two times and give rise to a 8 celled suspensor.The two terminal cells of the 4-celled proembryo divide transversely and longitudinally many times to form the embryo body.When the seeds are mature,the embryos are not differentiated in to organs yet.The embryo is the shield shaped when seeds are released from the capsule.The seeds composed of the testa,embryo and endsperm.
出处
《西北植物学报》
CAS
CSCD
北大核心
2014年第6期1131-1137,共7页
Acta Botanica Boreali-Occidentalia Sinica
基金
陕西省重点实验室项目资助(2014JS)
陕西省重点学科专项建设资金资助(2014)
关键词
黄花油点草
双受精
胚
胚乳
种子
Tricyrtis maculata （D.Don） Machride
double fertilization
embryo
endosperm
seed
