Studies On Drought-resistance And Cold-resistance In Five Specie Tree Seedlings Of Evergreen Broad-leaved

In the study,Zhejiang evergreen broad-leaved native trees Prunus zippeliana Miq., Lithocarpus glaber Thunb., Cinnamomum camphora Linn., Schima superba Gardn. and Photinia×frase'Red robin'for the test material, with the method of bonsai controlling the plant water and refrigerator freezing simulated to stress condition, the author studied the the effects of physiological indicators under the stress, and also analyzed its ability and mechanism of resistance by means of subordinate function method, with a view to introduction of drought and low temperature region and providing a theoretical basis for the greening application. The main results were described as follows:(1)The effects on the physiological indicators under different drought stress of the 5 evergreen broad-leaved species such as the relative water deficit (RWD) of Leaves, water protection, cell membrane permeation and proline (PRO) content were studied. When the soil water content was reduced, the modality characteristic of the five evergreen tree species was changed, the relative water deficit of Leaves increased and the speed of losing water decreased, cell membrane permeation and the content of proline increased under stress. The result also showed that the range of different tree species and stress time was not the same. Through comprehensive analysis of these indexes of 5 tree species with subordination function method, it was concluded that the drought resistant ability of these five species increased in order of Cinnamomum camphora,Schima superba,Lithocarpus glaber,Photinia×fraseri'Red robin'and Prunus zippeliana.(2)The effects on the physiological indicators under different temperature stress of the 5 species such as relative conductivity,the content of chlorophyll, superoxide dismutase, peroxidase and malondialdehyde content were different. the relative conductivity increased, the content of chlorophyll a, total chlorophyll and chlorophyll a/b decreased,SOD and POD activity strengthened at a certain range of temperature, the content of MDA increased under stress. The result also showed that the range of different tree species and stress time was not the same. Combination of comprehensive evaluation of membership function of the cold resistance ability in the five species, the result was: Cinnamomum camphora < Lithocarpus glaber