摘要
以不同强度UV-B照射3年生盆栽柑橘,研究柑橘的光合色素含量、净光合速率和叶绿素荧光特性对UV-B胁迫下的动态响应.结果表明:各处理Fm值显著下降,其中U5的Fm值下降幅度最大.除CK外,各处理Fo均上升.Fv/Fm,Fv/Fo值较UV-B辐射前显著下降,且随辐射时间的增长而降低.各处理QN的值均上升,其中U5上升65.7%.U5处理的QP较辐射前下降了,其它处理QP值均有所上升.随着UV-B辐射时间的增加,Yield,ETR,PSⅡ值逐步降低.且UV-B辐射25d后,各处理Yield,ETR,PSⅡ值最低,到30d时有所回升;UV-B胁迫30d后,对照组CK与U1的净光合速率Pn具有显著性差异,U5净光合速率最低.UV-B对各处理胞间二氧化碳浓度影响不大.各处理之间的气孔导度及蒸腾速率无显著差异,且U1的气孔导度和蒸腾速率都较其他处理高;随着UV-B辐射时间的增长,柑橘叶片中的Ca2+-ATPase活性明显升高.在轻度UV-B辐射下,柑橘能够通过自身的一些抗性机制及一些生理反应来抵御胁迫,但在强UV-B辐射下U5光合系统及细胞膜等受到一定程度的伤害,难以恢复到相应水平.
Three-year-old pot-grown plants of Citrus reticulata Banco were exposed to UV-B radiation at different intensity （natural light, 0.05 W/m2 , 0.10 W/m2, 0.15 W/m2 , 0.20 W/mz and 0.25 W/m2） and their pi so as to stu gm dy ent content, photosynthesis indexes and chlorophyll fluorescence parameters were recorded their responses to UV-B radiation stress. Fm decreased markedly in all enhanced UV-B radi- ation treatments, especially in US. Fo increased in all enhanced UV-B radiation treatments, while Fv/Fm and FV/Fo decreased with increasing duration of radiation. QN increased greatly in all UV-B treatments, by 65.7% in U5. Compared with the value prior to the treatment, QP dropped in U5 and rose to some ex- tent in other UV-B treatments. With the extension of UV-B radiation time, the values of yield, ETR and PSII decreased gradually. They declined to the lowest after 30 days UV-B radiation. After 30 days of UV-B levels after 25 days of UV-B radiation and increased radiation, Pn was significantly different between U1 and CK, and U5 had the lowest Pn. UV-B radiation treatment had no significant effect on Ci of the plants. No significant differences were observed among the treatments in Os and Tr, though U1 had slightly high- er Gs and Tr than the other treatments. Along with the increasing time of UV-B radiation, Caz＋-ATPase activity in the leaves increased apparently. Under slight UV-B radiation, citrus plant~ could resist the stress by means of some resistance mechanism and physiology reaction, but under heavy UV-B radiation of U5 their photosystems and plasmalemma were damaged so much that they could hardly recover.
出处
《西南大学学报（自然科学版）》
CAS
CSCD
北大核心
2014年第6期1-10,共10页
Journal of Southwest University(Natural Science Edition)
基金
国家自然科学基金(30500041)
重庆市科技攻关项目(cstc2012gg-yyjs80013)基金资助
