两种生境下狗牙根叶表皮亚显微结构的比较

通过对生长在田园土和植被砼2种生境下的5个品种狗牙根及野生狗牙根叶表皮微形态进行扫描电镜观察,比较了在不同生境下狗牙根叶表皮上气孔形状、大小、密度和表皮毛、乳突等附属物。结果表明,供试的5个狗牙根品种及野生狗牙根对植被砼环境作出了积极的响应与适应,上下表皮乳突明显较田园土的增多,并且有些狗牙根品种叶表皮的气孔器周围乳突有规律的排列,使气孔器凹陷在其周边的细胞里面,使气体扩散阻力增大,有利于降低蒸腾,增加植物对水分的利用效率。与田园土上生长狗牙根相比,植被砼上狗牙根上、下表皮气孔密度显著增高的有喀什狗牙根、Sahara、Heaven、Hawk。就植被砼上不同狗牙根气孔特征来说,气孔密度较其他品种显著多的品种有喀什狗牙根、Sahara。在供试的5个狗牙根品种及野生狗牙根中,根据表皮毛及其他附属物的形态特征,气孔参数的特征等综合考虑,认为Sahara、Hawk、喀什狗牙根等对植被砼生境有很好的适应性。

Comparative study on leaf epidermis submicroscopic structure of Cynodon dactylon under two habitats

The leaf epidermis submicroscopic structures of five varieties of Cynodon dactylon and wild bermudagrass planted in rural area soil and vegetation concrete were observed under scanning electron microscope(SEM).The shape,size and density of stomata on the leaf epidermis,epidermal appendages(mastoids,bristles etc.) of C.dactylon grown under the two habitats were compared.The five varieties and wild C.dactylon used in the experiments showed morphological responses to saline stress,and mastoids on upper and low epidermis increased,compared with control.On the epidermis of some varieties,such as Sahara,Hawk,and wild type,the mastoids around stomata distributed regularly,resulting in stomatal apparatuses below the cells around them.As the stomatal resistance increased,transpiration rate might decrease,and water usage efficiency might increase.Compared with control,increased stomatal density on upper and lower epidermis occurred on Kashi,Sahara,Heaven,and Hawk.According to the stomatal characteristics of the varieties grown on vegetation concrete,high stomatal density occurred on Kashi and Sahara.In general,among the five varieties of C.dactylon and wild bermudagrass used in this study,Sahara,Hawk,and Kashi showed better adaptation to vegetation concrete.