银杏叶生小孢子囊比较形态学及系统意义  

Comparative Morphology and Its Systematic Implication on Epiphyllous Microsporangia from Ginkgo biloba L.

作　　者：邢世岩[1] 李士美[1] 李保进[1] 王芳[1] 韩克杰[1] 王利[1] 

机构地区：[1]山东农业大学林学院,山东泰安271018

出　　处：《园艺学报》2007年第4期805-812,共8页Acta Horticulturae Sinica

基　　金：国家自然科学基金项目(30671707)

摘　　要：运用常规石蜡切片方法，结合光学显微镜和扫描电镜技术对作者发现的中国第一株叶生小孢子囊银杏的比较形态学及系统意义进行研究。叶生小孢子囊雄株有正常小孢子囊和叶生小孢子囊两种类型。叶生小孢子囊常着生在某些短枝的叶片边缘，这些叶片明显较正常叶片小，叶片顶端或两侧常有1-3个深裂刻（lobe），在裂刻处堆积1-9个不等的小孢子叶，或者小孢子叶1-3 （5）个聚生在叶柄叶片交界的叶柄两侧，小孢子叶无柄。着生小孢子囊的叶片除在小孢子囊着生处叶片加厚外，解剖结构和正常叶片无明显差异，均由表皮，叶肉，叶脉3部分组成，栅栏组织和海绵组织分化不明显。叶生小孢子囊的数量、着生位置和形态具多样性。正常小孢子囊近椭圆形，叶生小孢子囊近圆形，孢子囊壁4 -7层细胞，散粉期绒毡层已经退化，仅留痕迹，孢子囊内分布大量花粉。叶生小孢子叶的花粉极轴和赤道轴分别为19.99和13.60μm，每个叶生小孢子（花药）有花粉1.86万粒。正常花粉为光滑型，而叶生小孢子囊花粉为粗糙型。叶生小孢子囊花粉具有萌发能力。叶生小孢子囊银杏的个体发生，表明银杏的小孢子叶有叶性来源的性质，叶生小孢子囊银杏可能是一种奇特的嵌合体。对叶生小孢子囊银杏的系统发生进行了探讨。Comparative morphology of epiphyllous microsporangia Ginkgo, which was discovered by author for the first time in China, were examined under light microscope （LM） , scanning electron microscope （ SEM）, and its systematic implication was discussed. The research results showed that there exists the normal microsporangia and epiphyUous microsporangia on epiphyllous microsporangia Ginkgo tree. These leaves with epiphyllous microsporangia are smaller than that of normal leaves, and with 1 to 3 deep lobes attached by 1 - 9 microsporophyll, sometimes 1 - 3 （5） microsporophyll clustered on the boundary of lamina and petiole, and the microsporophyll without stalklet. There is no significant difference in anatomical structure between the leaves with epiphyllous microsporangia and normal leaves, except the thickening in the site where epiphyllous microsporangia inserted. The transections of both kinds of leaves comprise epidermis, mesophyll and veins, and there is no significant palisade tissue and spongy parenchyma. There is diversity in the number of epiphyl- lous microsporangia per leaf, inserted site, and morphological features. The normal microsporangia is elliptic, while the epiphyUous microsporangia is almost circular, and the microsporangia wall consists of 4 -7 layers of cell. At the time of pollen shedding, the tapetum was degenerated to vestige in both kinds of microsporangia. The polar axis and the equatorial axis of pollen produced in epiphyUous microsporangia are 19.99 μm and 13.60 μm, respectively. The number of pollen in epiphyllous microsporangia averages 18 600. Normal pollen is slippery-grained type, but epiphyllous potten is rougn-grained type.The pollens in epiphyllous microsporangia have capability to germinate. The ontogeny of epiphyllous microsporangia Ginkgo indicated that the microsporophyll in Ginkgo is of phyllome origin. Possibly, the epiphyllous microsporangia is a peculiar chimera. Phylogeny on epiphyllous microsporangia Ginkgo was discussed in the article.

关 键 词：银杏 叶籽银杏 叶生小孢子囊 比较形态学 系统发育 

分 类 号：S664.3[农业科学—果树学]