抗旱性不同的苹果属植物水分胁迫下核酸代谢及自由基变化

Effects of Water Stress on Nucleic Acid Metabolisms and Changes of Free Radicals in Malus

水分胁迫引起苹果属植物中抗旱性较弱的平邑甜茶和抗旱性较强的新疆野苹果幼苗叶片相对含水量 (RWC)、DNA、RNA含量下降 ,O-·2 、H2 O2 含量增高 ,DNase、RNase活性上升 ;其中DNA含量下降的幅度小于RNA ,DNase活性上升的幅度小于RNase。抗旱性较强的新疆野苹果在水分胁迫下幼苗叶片的RWC、DNA、RNA含量下降的幅度以及O-·2 、H2 O2 含量增高、DNase、RNase活性上升的幅度均小于抗旱性较弱的平邑甜茶。水分胁迫下平邑甜茶和新疆野苹果幼苗叶片的DNA、RNA含量与RWC、O-·2 、H2 O2 含量和DNase、RNase活性间均呈显著相关。

Effects of water stress on nucleic acid metabolisms and changes of free radicals in Malus hupehensis pamp Reld. and Malus sieversii (Ledeb) Roem. seedings were studied with polyethylene glycol (PEG 6000) treatment. Under water stress , the contents of RWC, DNA and RNA in leaves decreased, while the content of O -· 2 and H 2O 2 , the activities of DNase and RNase increased. Compared with RNA, the less decrement of DNA content was accompanied with higher activity of DNase. The changing extents in RWC, active oxygen, DNA, RNA, DNase and RNase in the drought tolerant variety M. sieversii were lower than the drought resistant variety M. hupehensis . Under water stress, there are high significant correlation between DNA, RNA content and DNase , RNase , RWC, O -· 2, H 2O 2 in M. hupehensis pamp Reld. and M. sieversii (Ledeb) Roem. seedings.