红花檵木叶色转变过程中的叶表皮特征变化

红花檵木是一种在园林绿化上广泛应用的彩叶植物,叶色夏季会出现"返青"现象,导致观赏价值降低。对红花檵木的红叶、转绿后的绿叶和回复突变的绿叶以及原变种檵木的叶片的叶表皮特征进行了研究发现:①檵木及其变种红花檵木的不同叶片中表皮毛均为单细胞型,有单根型的,也有2~多根表皮毛1束型的,以1~4根1束的表皮毛类型为主,表皮毛的分布下表皮均多于上表皮;②表皮毛的分布规律檵木与红叶相似,转绿与复绿相似,红花檵木转绿后表皮毛的数量下降60%以上;③红花檵木叶片转绿后上表皮细胞显著缩小,下表皮和气孔器略微增大,气孔指数无显著变化。

Variation of Leaf Epidermis Traits Duing Leaf Color Transformation in Loropetalum chinense var.rubrum

Loropetalum chinense Olive var.rubrum Yieh has been widely used to beautify cities and roads because of its red leaves,which,however,will turn green during summertime.This study was made on the leaf epidermis,trichomes,Stomata of red leaves,green leaves of L.chinense Olive var.rubrum and green leaves of its back mutation,and leaves of L.Olive.The results showed: ① Trichomes of L.chinense and its variation were composed of single cells.Some were simple trichomes,some were 2 or more armed,of which most were simple and 2 to 4 armed.The trichomes distributed on the down-epidermis were more than those on the up-epidermis.② The distribution rule of trichomes on the leaves of L.chinense was the same as that on the red leaves of L.chinense var.rubrum,and on the green leaves of L.chinense var.rubrum was the same as that on the leaves of back mutation.After turning green,the number of trichomes on the leaves epidermis decreased dramatically.③ After red leaves turned green,up-epidermis cell size shrank remarkably,while down-epidermis cell size and stomata increased slightly,and stomata index changed little.