摘要
在云南干旱地区广泛用作薪炭林的树种香须，粉花山扁豆，刺槐和银合欢的幼苗被不同浓度的ＰＥＧ诱导水分胁迫后，相对含水量随ＰＥＧ的浓度增大而下降，质膜透性随ＰＥＣ浓度升高而增大；ＳＯＤ活性基本上也随ＰＥＧ浓度升高而增大。质膜透性与相对含水量呈极显著负相关（ｒ＝０．９２，ｐ＜０．０１），说明干旱脱水使质膜伤害；游离脯氨酸的累积量在ＰＥＧ处理后大幅度上升，增长幅度与树种的相对含水量有关，相对含水量低增长少，相对含水量高增长高，表明脯氨酸有保水作用。ＳＯＤ活性与相对含水量呈显著负相关（ｒ＝－０．６１，ｐ＜０．０５），说明干旱脱水将诱导ＳＯＤ活性增大，以防止或减轻超氧物阴离子自由基Ｏ对膜的伤害作用。揭示和阐明这些树种在水分胁迫中的生理特性，有助于干旱地区造林时对宜林树种的选择。
Albizia ocloratissima,Cassia nodosa,Robinia pseudoacacia,and Leucocena leucocephala were considerd as drought resistance plants and grew in dry regions of yunnan. In this experiment,their seedlings were treated with different concentration of polyethylene glycol(PEG）.The relative water content(RWC)and plasma membrane permeability of their hypocotyl,the proline accumulation and superoxide dismutase(SOD)activity of their leaves were tested under water stress.The results showed that the RWC decreased and plasma membrane permeability increased with the increase of PEG concentration. There was a negative correlation (r=-0.92,p＜001)between the RWC and plasma membrane permeability,which indicated that plasma membrane was injured during dehydration. The amount of free proline accumulation increased greatly with waterstress．The proline accumulation was related to the RWC of the trees．The proline accumu-lation level of Albizia ocloratissima which had the highest RWC was the highest．It was suggested that proline plays an important role in the water retention of these species.TheSOD activities were intensified when these species were treated with PEG. There was a negative correlation( r=-0.61,p＜0.05)between the SOD activity and RWC. Increase of SOD activity was a physiological characteristic of drought resistance plants after water stress.SOD might protect plasma membrane from being injured by O2.So these species were all suggested to be drought resistant.It was helpful for afforestation species selection in drought regions and for the investigation of the physiological features of these drought resistance trees.
出处
《西南林学院学报》
1994年第3期149-154,共6页
Journal of Southwest Forestry College
基金
云南省薪炭林<八五>重大科技攻关资助项目
关键词
水分胁迫
聚乙二醇
薪炭林
树种
诱导
Water stress
Polyethyene glycol
Reltive water content
Plasma membrane permeability
Proline
Superoxide dismutase
Fueltrees
