The Observation Of Leaf Surface Structure Of Qingdao Common Garden Tree

Leaf is the main organ for plant contacting with the outside world.During the long-term process of natural selection, the leaf form a complex morphological features that meet the needs of functions.Understanding the leaf surface morphology of garden plants and discussing the relationship between morphological structure and ecological function have important significance for landscape tree species selection and landscape ecological function research. The cutin of leaf surface, epidermal hairs, glandular hairs, epidermis cells and stomata of 64 landscape trees in Qingdao were investigated using scanning electron microscope. The results show that:1. In 6 Pinaceae trees, the stereo configuration of the needles are not the same. Except Pinus armandii and Pinus parviflora which only have two of the surface porosity belt, each other plants surface has a porosity belt.All stomata are in linear arrangement. Stomatal apparatus are elliptic. Pinus bungeana and Cedrus deodara accessory cells are parallel to the leaf surface,other plants accessory cells are obviously swelled. Pinus armandii and Pinus parviflora have relatively similar leaf surface ultrastructure.But the row arrangement of Pinus armandii stomatal apparatus are mostly alternate,Punus parviflora are mostly opposite.2. In 5 Cupressaceae trees, stomata only distribute on the adaxial surface of Sabina chinensis(L.)Ant. but other plant leaves’ stomata are on both sides. The stomata of abaxiall surface distributes in two scales at the junction.Only the Sabina squamata s stomata arrangement are in strip shape. The Abaxial stomatic distribution range of Platyclads Spach cv.Aurea Nana is greater than Sabina chinensis(L.)Ant. and Sabina chinensis(L.)Ant.cv.Kaizuca. Stomatal morphological characteristics are similar in the 5 Cupressaceae trees.Stomatal long axis parallel to leaf midrib.3. Stomatal features of evergreen broadleaf trees are different. There are two types of stomata-irregular and row.Stomatal shapes are oval, suborbicular, oblong, or copper. Significant differences were found in different plants’stomata length and density.Most plants cannot observed epidermal cell morphology.There are three kinds of plant distributing with glandular hairs. Ligustrum lucidum,Ligustrum japonicum had peltate glandular hairs or capitate glandular hairs. Rhododendron molle had rod glandular hairs. Magnolia Grandiflora and other four kinds of plants have different types of linear hairs.4. In 32 deciduous landscape trees, leaf stomata of all trees were all irregular. The vast majority of leaf stomata distribute only in blade axial plane.Stomatal shape are elliptic or suborbicula. Most of the plants stomatal apparatus and leaf epidermis are at the same horizontal plane.The stomata length of Rosa chinensis is significantly longer than those of other species which stomata length are between 5-15μm. Celtis sinensis stomatal density is significantly higher than other plants.The far axial surface skin cell of Albizia julibrissin and Magnolia denudata are significantly raised nearly sphere or ellipsoid. Syringa oblata etc had peltate glandular hairs or capitate glandular hairs. Cotinus coggygria and Zelkova serrata had rod glandular hairs. Platanus orientalis and Firmiana platanifolia had branched arborization hairs and stellate hairs respectively. And the others species had linear epidermal hair.5. Sink in the Pinaceae and Cupressaceae plants’guard cells and the stomata of abaxiall surface distributing in two scales at the junction, which Suppress the leaf transpiration and improve the drought resistance.Overall, deciduous broad leaved tree species of stomatal density is greater than the evergreen broad leaved tree species’.Larger stomatal density is beneficial to the regulation of water. The vast majority of the stomatic distribution of broad leaved tree species are in vane axial surface, which can improve the drought resistance. The thicker cuticle of evergreen plants improve the drought resistance, cold resistance and disease resistance of plants. Some plants glandular hairs’ secretions can improve the plant disease resistance.