水分胁迫下抗旱性不同的两种苹果属植物光合特性的变化

Changes of Physiological Characteristic on Photosynthesis in Malus Seedling Leaves during Water Stress

水分胁迫使苹果属植物叶绿素 -蛋白质 (Chl Pro)结合度松弛 ,净光合速率 (Pn)、气孔导度下降 ,胞间CO2 浓度先降后升 ,SOD、CAT活性先升后降 ,类胡萝卜素、抗坏血酸含量大幅度降低 ,O·2产生速率、H2 O2 含量增高 ;这些参数下降和上升的幅度均为 :平邑甜茶 >新疆野苹果。水分胁迫下平邑甜茶和新疆野苹果幼苗叶片的Pn与其Chl Pro、O·2 、H2 O2 间均呈显著负相关。表明水分胁迫对苹果属植物光合速率的影响除受气孔因素限制之外 。

Changes of physiological characteristic on photosynthesis in Malus seedling leaves during water stress were studied with polyethylene glycol(PEG 6000)treatment.The results were as follows:Under water stress,the binding of Chl Pro was loosened with the changes of time and intensity of water stress.Net photosynthesis rate(Pn),stomatal conductance(Gs)decreased,intercellular CO 2 concentration(Ci) increased ,then decreased.The activities of SOD,CAT increased in the early period,then decreased.The O [BHDFG1.5mm,WK1.5mmW]· 2 generating rate and contents of H 2O 2 increased during water stress,the content of antioxidants carotenoid(Car)?ASA decreased.The changing extents of these parameters in the drought tolerant variety M.sieversii were lower than the drought resistive variety M.hupehensis .Under water stress,there are high negative significant correlation between Pn and Chl Pro O [BHDFG1.5mm,WK1.5mmW]· 2,H 2O 2 in M.hupehensis (Pamp.)Reld.and M.sieversii (Ledeb.)Roem.seedlings.With the duration of water stress,the excessive accumulation of O [BHDFG1.5mm,WK1.5mmW]· 2,H 2O 2 induced the nonstomatal limitation.It played key role in the decline of the photosynthetic rate.