Study On Tolerant Ability Of Three Species Of Photinia L. Under NaCl Stress

In potted plant experiment, physiological responses (growth, physiological and biochemical indicators) to soil NaCl stress(0.2%,0.3%,0.4%,0.5%,0.6%) were studied in three species of Photinia L.: Photinia serrulata, Photinia×fraseri'Red Robin', Photinia glabra var.robens), and appraised the comprehensive salt tolerant ability of these species. The main results were described as follows:1. With NaCl stress concentrations increased, the leaves of three species of Photinia L. were becoming yellow, chlorosis, dry and dead. Under high concentrations of salt stress, it seems Photinia×fraseri'Red Robin'tends to suffer the least, Photinia glabra var.robens the second and Photinia serrulata the most.2. The relative leaf water content of three species had a continuous downward trend with the stress concentrations and the time goes on. The membrane permeability, MDA and soluble sugar content of the three species showed a continuous upward trend with stress concentrations and the time goes on. The chlorophyll content and SOD activity of the three species increased after the first drop trend. The soluble protein content of Photinia serrulata and Photinia glabra var.robens showed a continuous downward trend with the stress concentrations and the time goes on, meanwhile the soluble protein content of Photinia×fraseri'Red Robin'generally showed a continuous downward trend but with a mildly upward progress.3. By the way of principal component analysis, there comes the result of closeness relationship between the membrane permeability, soluble sugar content, MDA, SOD activity and the tolerant ability of three species of Photinia L..4. The comprehensive salt tolerant ability of three species was analyzed by subordinate function. The result was that the rank of salt tolerant ability of three species was Photinia×fraseri'Red Robin'> Photinia glabra var.robens > Photinia serrulata.