【摘要】 陈介(1964)在四棱草属(Schnabelia)中发现具有二型花,即开花授粉型的花(chasmogamous)和闭花授粉型的花(cleistoga-mous)。他根据当时所掌握的材料,认为二型花“似乎是异株”。笔者在采自安徽祁门的四棱草(S.oligophylla)上发现,二型花无疑是生在同一个体上,但这两种花的花期和花的着生位置是不同的。开花授粉型花的花期早,持续时间短,为一次性开花;闭花授粉型的花是不断地从叶腋发出的,花期持续时间长。经研究发现在单花获(Caryopteris nepetaefolia)和韩信草(Scutillaria indica)中也存在相似的二型花,说明这现象在被子植物中不是个别的,而是某些植物种的生物学特性,是长期自然选择的结果,无疑在植物的进化上有一定的意义。但是也发现四棱草(S.oligophylla)的开花授粉型的花中存在的某些性状对异花受精不是良好的适应,相反由于它的存在阻碍了异花受精,同时造成强迫性自花受精。更多还原

【Abstract】 C. Chein (1964) discovered for the first time the twotypes of flowers, chasmogamous and cleistogamous in genusSchnabelia. Based on the materials available, he then pointedout that the problem whether the two types of flowers of thegenus Schnabelia existed on the same individual plants or on thedifferent individuals still remained unclear, and that theyseemed to be on the different plants. The present research in to S. oligophylla Hand. - Mazz.collected from Qimen of Anhui Province make it distinct thatthe two types of flowers undoubtedly exist on the same plant.So far as the time of their appearance is concerned, the chas-mogamous flowers precede the cleistogamous ones. As for theirpositions, they situated themelves separately on their own cy-mes, and come out of the leaf axils above the near base, atthe same time the cleistogamous ones do out the lowest base of the chasmogamous flower’s peduncle after these flowers wi-thering. The occurrence of the cleistogamous flowers probablyhas something to do with the inf1uence of the environmen-tal factors. Having transplanted some S. oligophylla from the growingarea to Hefei, the author observed after potting it, that theflowers which came out in the year were chasmogamous,while the flowers that appeared early next year were chas-mogamous, and then came out the cleistogamous ones. Asfor manner of fertilization, a cleistogamous flower is ob--viously that of self--fertilization. The chasmogamous flowers,rich in colour, is suited to entomophilous pollination, but thesurface of their anthers is covered with sparse arachnoidhairs. At the time when the alabustrum is just about flower,the top parts of the filaments incurved and the anthers con-tact with one another laterally to form a ring, throughwhich the style just pierces when it extends. Nevertheless, thearachnoid hairs on the surface of the anthers adhere to thebranchlets of the style. After flowering, the stamens andthe style begin to stretch straight. From this phenomenonmay be seen that the chasmogamous flowers probably havethe self--fertilization capability, which, when the cross--pol-lination fails ensures the work of self--fertilization. It should be particularly pointed out that having studiedthe two types of flowers of the genus Schnabelia, the presentwriter discovered that the two types of flowers of Caryopterisnepetaefolia and Scutillaria indica have quite the same structureas those of the genus Schnabelia too. In the species with the two types of flowers, the mannersof fertilization of flowers are altogether differently. Generalythe conspicusous flowers (chasmogamous) are cross-fertilizationand cleistogmous only adapt to self--fertilization. It is shownthat this genetic system is unprofitable to the populations ofcleistogamous of which the two types of flowers exist on the different plants, which finally will lead to completely homo-zygous and become a single biotype consisting of geneticallysimilar individuals. For the species of the two types of flo-wer, on the same individual plant, the genetic system may bebetter than above one, because such plants not only produce agreat many seeds which are the result of self--fertilization, butmay also form a favourable gene combination following inter-racial hybridization of chasmogamous. But the author foundthat interracial hybridization in chasmogamous of S. oligophyl-la appears difficult because of the arachnoid haris on surface oftheir anthers, which alaways adhere to the branchlets of thestyle, so the self--fertilization is compelled to facilitate. Itis shown that there are some shortages in the chasmogamous ofS. oligophylla.更多还原