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作 者 ：童本群

期 刊 ：林业科学 1983年 19卷 4期 页码：342-348

关键词：红松；

摘 要 ：红松的传粉和受精之间约经12个多月。翌年4月中旬,越冬后的雌配子体开始发育。5月下旬末,颈卵器原始细胞出现。6月中旬,中央细胞不均等地分裂为1个小的双凸透镜状的腹沟细胞和1个大的卵细胞。成熟的卵细胞长约550—880微米,宽约370—650微米。此时,花粉管中精原细胞分裂为2个大小不同的精子。具功能的大精子趋近卵核。6月21—25日发生受精。雌雄两性核和胞质的融合过程是:(1)精子核与卵核接触;(2)核膜的融合;(3)雌雄染色质的凝集;(4)形成雌雄两群染色体和各自的纺锤体;(5)雌雄两组纺锤体合并成1个二极的纺锤体;(6)合子核的分裂;(7)雌雄两性细胞质重组形成新细胞质。本文对卵细胞质中蛋白泡的细微结构,受精作用中雌雄性核的融合方式,以及合子新细胞质的形成,进行了讨论。

Abstract:The cytology of oogenesis and fertilization in Korean pine (Pinus koraiensis Sieb.et Zucc.),has been investigated.The material on which these investigations were made was collected at Benxi County,Liaoning.The results are briefly summarized as follows: 1. Oogenesis After the gametophyte starts developing in the followingspring,the archegonial initials appear towards the end of May (1980).Then the nucleus of the archegonial initial comes to lie towards the upper end of the cell,the first division is followed by a transverse wall giving rise to the primary neck cell and the central cell.The neck cell divides by two vertical walls at right angles to each other resulting in four cells,which lie in a single tier.The central cell enlarges rapidly but as there is no corresponding increase in the amount of cytoplasm,numerous vacuoles are formed.Later the vacuoles tend to disappear and the cytoplasm becomes denser.Small globular structures appear,and occur singly or in groups of two or several.These are called "proteid vacuoles".The jacket cells surround the archegonium except in the neck region.In the middle of June, the nucleus of the central cell divides to form two nuclei separated by a phragmoplast.The wall laid down between them separates a small, lenticular ventral canal cell from the large egg cell.The ventral canal cell soon degenerates and only its remnants can be seen.The egg nucleus migrates towards the centre.While doing so it greatly increases in size. The archegonia are single,2(3—5) in number.The egg is elongatoellipsoidal,about 550—880×370—650μ in size,and its nucleus is large,140—200×110—170μ. 2. Fertilization,The pollen tube makes its way between the neck cells. Both the sperm nuclei along with the tube nucleus,stalk cell and cytoplasm are released inside the archegonium.The larger of the male gamates proceeds towards the egg nucleus,while the smaller along with the stalk nucleus generally remains in the upper part of the archegonium and ultimately disintegrates.The functional sperm nucleus becomes pressed against the egg nucleus.The fertilization took place about June 21—25 (1980).The essential process of the fusion of egg and sperm nuclei during syngamy could be outlined as follows:(1)the sperm nucleus made contact with the egg nucleus;(2) the fusion of nuclear membranes happened between the male and female nuclei;(3) the male and female chromatins condensed to form two separate groups of chromatic threads;(4) the male and female chromosomes grouped respectively in their own spindles;(5) then the two spindles fused together and all the chromosomes become arranged at equator of this broad spindle;(6)two daugter nuclei resulted from the mitotic division;(7) finally the neocytoplasm formed from the male and female cytoplasm. The ultrastructural features of the proteid vacuoles in egg cytoplasm, pattern of the fusion of male and female nuclei in fertilization and formation of the neocytoplasm during the first division of the zygote nucleus are also discussed in the present paper.

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