摘要
【目的】盐胁迫对盐桦幼树光合特性的影响。【方法】利用土壤含盐量为1．0％、1．2％、1．4％、1．6％、1．8％、2．0％和2．2％七个盐浓度梯度，处理1年生盐桦实生苗，0％为对照CK，在生长的不同阶段分别测定叶片光合速率及其它生理指标。【结果】盐处理后，叶片净光合速率和气孔导度（Cond）均随NaCl浓度提高而显著降低；胞间C02浓度（Ci）、蒸腾速率Tr，随NaCl浓度提高呈先降低后升高的趋势；试验中1．6％NaCl胁迫下，盐桦幼树叶绿素含量提高，而1．6％。2．2％NaCl胁迫使叶绿素含量开始降低。【结论】NaCl胁迫下叶绿素含量提高是由于Na^＋的吸收促进了生长，也有利于叶绿素的合成；1．4％-1．6％NaCl胁迫下叶绿素含量提高是由于盐胁迫下叶片生长缓慢，导致叶绿体收缩，产生“浓缩”效应；1．4％NaCl胁迫下叶绿素含量仍然提高则可能是NaCl胁迫提高了叶绿素酶的活性，使光合色素合成减少、分解增加，从而使光合色素易于提取而导致了测得的叶绿素含量提高。
[Objective and Method]The pot experiments were applied to study the effect of salt stress on the net photosynthetic rate （ Pn ） and other physiological properties of 1 - year Betula halophila seedling. The seedlings were treated with NaC1 concentrations of 1.0 %, 1.2 %, 1.4 %, 1.6 %, 1.8 %, 2.0 %, 2.2 % and 0 % （ CK }. [Result] Results show that the net photosynthetic rate（Pn） and stomatal conductance （Cond） were significantly decreased with the increasing of NaCl eoncentrantion ; the intercellular CO2 concentration （Ci） and transpiration rate first were decreased then increased with the increasing of NaCl concentration. The chlorophyll content of Betula halophila seedling were increased after 1.6% NaCl treatment, but it was decreased with 1.6% and 2.2% NaCl treatment. [ Conclusion]It was knowen that under NaCl stress, the chlorophyll content was increased and promoted the growth of the seeding by absorbing Na ＋ , and advantageous to the synthesis of chlorophyll. When the seeding was treated by 1.4% and 1.6% NaC1, chloroplast contract arise from the slow growth of leaves, which caused contracting of chlorophore . Under treatment by 1.4% NaC1, the chlorophyll content was still increased. Photosynthetic pigment was refined more easily , so the determination of chlorophyll content was high.
出处
《新疆农业科学》
CAS
CSCD
北大核心
2010年第2期213-217,共5页
Xinjiang Agricultural Sciences
基金
国家林业局重点科学技术计划项目(2003-015-L5)
关键词
盐桦
盐胁迫
光合速率
叶绿素
Betula halophila
salt stress
photosynthetic properties
photosynthetic pigment
