Study On The Comparative Structure Of Ulmus Pumila L.in Different Environments Of Henan And Jilin

This research,by combining the production technique of the leaf's plant print,the technique of paraffin section,freehand section technique of wood's three sections,the technique of dispersing wood's vessel elements,optical photomicrography technique and mathematical statistic analysis technique,had a comparative research on the anatomical structure of Ulmus pumila L.which grow in diverse geographical circumstances: Henan(sun ecological surroundings)and Changchun(dankness).Anatomical structures which were studied include leaves,petioles,young stem,wood's secondary xylem and dispersed timber's vessel elements of Ulmus pumila L.growing in two different kinds of geographical environments.The consequences of plant prints identification experiment showed : the leaves' epidermic cells anticlinal wall style of Ulmus pumila L.growing in two different kinds of geographical environments is G type.Subsidiary cells in a radiation type.But the results of the measure and statistical analysis with Nis-Elements D 2.20,sp2(Build 243)and SPSS20.0 showed that the stomatal apparatus' length and width of leaf epidermis,guard cells' perimeter and area,epidermal cells' size of Henan's Ulmus pumila L.are all smaller than Changchun's measured value,besides the stomatal index and stomatal density are higher,and the stomas always sink,but most of Changchun's stomas bulge outward.These are good for them to adapt to their different living environment.The mathematical statistic's results showed: the basic structure of Henan's and Changchun's Ulmus pumila L.keeps homology,but outside cuticle of the epidermis in Henan's vegetative structures which have more epidermal hairs are thicker,there is no heterocyst in Henan's epidermal cells,and vascular tissues,mechnical tissues and storage tissues of Henan's are all stronger than Changchun's.The ratio of Henan leaves' palisade tissue thickness to spongy tissue thickness is also larger than Changchun's.The edidermis' outside in Changchun's vegetative structures which have few epidermal hairs almost has no cuticle.There are some heterocysts in Changchun's epidermal cells,and aerenchyma of Changchun's vegetative structures is developed.These are the consequence of structure's evolution for each of them to adapt to drought stress and dankness stress.The experimental results of wood's three sections and dispersed timber's vessel elements of Ulmus pumila L.showed: the timbers of Henan's belong to diffuse-porus wood,and the timbers of Changchun's belong to ring porous wood.The number of Henan's vessel elements is larger,and the pore size of Henan's catheters is bigger,but the length of Henan's catheters is shorter than Changchun's,besides the proportion of catheters with no tail or short tail is more than that in Changchun.These prove that Henan's catheter type is more evolution,its a large number and big pore size of catheters are more beneficial to the water transport.There are a large number of single pits on the upright ray cell wall,and this is the result of adapting to the xeric environment.In summary,it proves that Henan's pumila evolved structures with antagonism to the drought stress and Changchun's pumila evolved structures with antagonism to the dankness stress under their different geographical and ecological environment.This research has provided references data of evolutionary structural botany's study for the rational development and utilization of Ulmus pumila L.and the following research of plants stress resistance.