基质盐度对木榄叶柄导管分子形态特征的影响

对温室中培养在不同盐度下一年生木榄Bruginera gyninorrhiza(L.)Poil]植株上成熟叶的叶柄离析研究的结果表明:1)木榄叶柄导管分子以梯纹导管为主,其次为螺纹导管及它们之间的过渡类型;随着盐度的升高,螺纹导管及它们之间的过渡类型有增多的趋势;2)而叶柄长度,梯纹导管分子的直径、长度及两端梯状穿孔板的横隔条数都与盐度呈抛物线关系,而它们的最大位出现在20‰-30‰,范围内;3)培养于盐度10‰的海水中的木榄叶柄中导管分子一端有出现两个朝向不同的梯状穿孔板现象;4)在低盐条件下,随着基质盐度的提高,导管分子的形态朝着有利于加快水分运输的方向发展,而在高盐环境下,导管分子的形态朝着增加水分运输的安全性方向发展。讨论了叶柄导管分子解剖学特征的适应意义。

INFLUENCE OF SUBSTRATE SALINITY ON STRUTURE CHARACTERISTICS OF PETIOLE VESSEL ELEMENTS OF BRUGUIERA GYMNORRHIZA

The anatomy of the mature leaf s petioles of one-year-old Bruguiera gyrnnorrhiza seedlings cultured in greenhouse was studied in this paper. The results are as follows: (1) Most of the vessel elements of the petioles of B. gynniorrhiza are of scalariform. Helical vessels and their transition type only account for a small porlion of the total vessels. However, there is a notable increase in the number of helical vessels and their transition type with increasing salinity. (2) The length of petioles, diameter and length of scalariform vessel el ements, and bar number of a scalariform perforation plate all exhibit of parabolic relationship with subslrale salinity. They maximized at salinity between 20 g/L and 30 g/L. (3) It is new phenomenon that there ,m two scalariform perforation plates, facing differently, at the polar of the vessel element of the petioles in the seedlings under 10 g/L treatment. (4) Under low salinity, the changes in the structure of vessel elements had the tendency to promote the transportation of water with increasing salinity. While under high salinity, it tend ed to raise the reliability of the water transportation. The adaptive significance of the morphological characteristics of vessel elements in the petiole was discussed.