摘要
应用控制授粉、常规石蜡切片技术研究了中国鹅掌楸与北美鹅掌楸种间杂交后的胚胎发育过程。结果表明：（１）控制授粉后花粉正常萌发，并有较多的花粉管进入柱头，但花粉管在花柱内生长缓慢甚至解体；（２）花粉萌发６ｄ后花粉管经花柱沟、珠孔塞和珠心冠原组织进入胚囊进行珠孔受精，２０ｄ时游离核胚乳细胞化，发育形成２～４个细胞厚的狭长组织，３５ｄ后可观察到球形胚；（３）随着胚和胚乳的发育，珠被发育形成种皮。授粉时，胚珠具２层珠被，外、内珠被均由外表皮、中层和内表皮组成；胚与胚乳发育期间，珠被各层发生了一系列的变化，最终种皮由外珠被的外表皮细胞形成的膜层和中层细胞形成的气室以及内、外珠被内表皮细胞形成的硬化层组成；（４）受精时成熟胚囊及到达珠孔的花粉管的数目较少，受精频率较低；（５）受精过程基本正常，但胚和胚乳发育不协调，导致胚在发育早期败育，很难观察到后期胚的发生。
The embryogenesis of interspecific hybrids between Liriodendron tulipifera and L.
chinense was studied by means of artificial pollination and routine paraffin-embedded
sectioning technique. The results were:(1 )The pollen of L. tulipifera germinated normally after
artificial pollination,and more pollen tubes could grow into stigma but a lot of pollen tubes
grew slowly and even broke up in the style canal;(2)When the pollen has germinated for six
days,the pollen tube reached the embryo sac finally through the style canal,obturator and
nucellar cap,then,the porogamy was conducted.After 20 days, the cellular endosperm was
formed first as a narrow tissue of 2 to 4 eclls in thickness. The spherical embryo could be
observed after 35 days;(3)The seed coat was formed by integment following the develop-ment
of embryo and endosperm. The antropous has two layers integments. Both of them were
formed exopleura, middle layer and endopleura. Each layer of integment experienced a series
of changs when the embryo and endosperm developed. At last,the seed Coat was con-sisted of
the membrane layer formed by exopleura of exointegment, air chamer formed by middle layer
and hardening layers formed by the endopleura cell of inter integument and out- er
integument;(4)The number of mature embryo sacs and pollen tubes reaching micropyle was
too less to fertilize;(5)The course of fertilization was normal on the whole,but the de- velopment
of embryo and endosperm was not in harmony, which resulted in the early abor- tion of
embryo,so it was difficult to observe the later development of embryo.
出处
《林业科学研究》
CSCD
北大核心
1995年第6期605-610,共6页
Forest Research
基金
1991~1993年国家自然科学基金
关键词
中国鹅掌楸
北美鹅掌楸
种间杂交
Liriodendron
chinense,Liriodendron tulipifera,speciescross,embryo de- velopment
