The Research On The Ability Of Cold Resistance And Biological Characteristics Of Photinia Plants

The plants of Photinia genus can resist low temperature stress. The main purpose was to disclose the physiological ecology acclimation mechanisms. Then the comprehensive value of different plants'cold resistance ability could be obtained .The membrane leakage increased while the temperature decreased. The relative electric conductivity distributed as"S"curve. The semilethal temperature of different plants were got from Logistic equation . The Photinia glabra got the highest cold resistant ability followed by Photinia davidsoniae and Photinia serrulata in the bearing tree experiment. The results also showed that the semilethal temperature of the trees in the Nov.2005 was lower than that at the beginning of Jan.2006, and the cold resistance ability of five trees could be ordered as : Photinia glabra var.Rubens,Photinia×fraseri'Robusta',Photinia serrulata,Photinia×fraseri'Red Robin',Photinia×fraseri'Red Tip'。The relative electric conductivity and the semilethal temperature is the best index to evaluate the cold resistance ability, and the MDA,SOD,CAT could only be the assistant index to evaluate the ability., otherwise the POD need to be studied yet .The investigated results revealed that the temperature was the essential environmental factor affecting the seedling growth, while the high temperature restrained the growth of Photinia×fraseri. However, the humidity and amount of precipitation do nothing to the growth of Photinia×fraseri.The results showed that the amount of growth of different Photinia×fraseri differed much. The'Red Robin'had the most power growth potential than the'Robusta'which only increased 28.7 centimeters, while the'Red Tip','Rubens'showed a good growth potential.The'Red Robin'differed other trees with sharply-toothed ,big and leathery leaves, red annual branches; th'eRed Tip'had minutely serrulate leaves, red annual branches; the'Robusta'differed others with bright-green stalk and orange red leaves; the'Rubens'had a minimum size leaves with sealing-wax-red and minutely serrulate characteristics.