摘要
以人工低温处理尾叶桉和邓恩桉幼苗,研究其对两种桉树的光合生理特性的影响。结果表明:低温处理后两种桉树叶绿素含量下降、SOD活性上升、MDA含量增加,光合特性参数Pn、Gs和Tr下降,Ls值上升,而Ci则先上升后下降。进一步的分析表明,在持续低温胁迫的初始阶段,导致两种桉树Pn的降低的主要因素为非气孔因素,而随着低温处理持续时间延长至48 h时,气孔限制因素也逐渐成为Pn的降低的主要因素之一。低温处理对两种桉树的影响程度有较为明显的差异,对尾叶桉的影响明显要大于对邓恩桉的影响。
Photosynthetic and physiological responses of E. urophylla and E. dunnii seedlings to low temperature stresses were measured in this paper. The results showed that net photosynthetic rate（Pn）, Stomatal conductance（ Gs）, transpiration rate（Tr） and the content of chlorophyll of E. urophylla and E. dunnii seedling leaves decreased by low temperature treatments but stomata limitation （Ls） and the content of SOD and MDA increased. The intercellular CO2 concentration （Ci） increased first and then decreased. The decrease of Pn was mostly caused by non-stomatal factors at the beginning of low-temperature stresses, subsequently by stomatal factors and non-stomatal factors simultaneity. Photosynthetic and physiological responses of E. urophyUa and E. dunnii to low temperature stress had obvious differences, and E. dunnii had an greater tolerance to low-temperature stresses than E. urophyUa.
出处
《林业科技开发》
2008年第6期51-53,共3页
China Forestry Science and Technology
基金
国家林业局948项目“邓恩桉遗传改良及其杂交育种技术引进”(编号:2006-4-66)
广西科学研究与技术开发计划项目“耐寒桉新品种邓恩桉遗传改良技术研究与示范”(编号:桂科基0639023)
关键词
低温胁迫
光舍特性
尾叶按
邓恩按
Low temperature stress
Photosynthetic characteristic
Eucalyptus urophylla
Eucalyptus dunnii
