镧对越橘幼苗光合生理的影响

Effect of Lanthanum on Photosynthesis of Vaccinium Plantlets

为考察稀土镧对越橘光合作用的影响,测定了喷施低浓度(10,20,30和40 mg/L)LaCl3后越橘叶片气体交换参数连续7 d的变化趋势,并在处理7 d后测定了叶片光合色素含量及叶绿体质膜ATPase活性的变化。结果表明,LaCl3处理后第1天,越橘幼苗的净光合速率(Pn)、气孔导度(Gs)、细胞间隙CO2浓度(Ci)及蒸腾速率(Tr)即有较大增幅,在处理后7 d仍显著高于对照;同时,叶片光合色素含量、叶绿素a/b值及叶绿体膜Ca2+-ATPase和Mg2+-AT-Pase活性也都得到显著提高。说明LaCl3能提高越橘幼苗光合能力。试验结果还表明,LaCl3浓度为20 mg/L时效果最好,光合作用各生理指标值较对照提高最多。

To investigate the effect of rare earth lanthanum （La） on photosynthesis of Vaccinium plantlets, the changes of gas exchange parameters, photosynthetic pigment contents and ATPase activity of chloroplast membrane of Vac- cinium plantlets were studied after pretreated by different concentrations of LaCl3（ 10,20,30 and 40 mg/L） among one week. The results showed that net photosynthetic rate （Pn）, stomatal conductance （Gs）, intercellular CO2 concentration （Ci） and transpiration rate （Tr） were enhanced remarkably in the whole stage. 7 days after treatment, the contents of pho- tosynthetic pigment, the values of chlorophyll a/b and ATPase activity were also promoted significantly. The results indi- cate that LaCl3 could improve photosynthetic capacity of Vaccinium plantlets. Additionally, the results showed that 20 mg/L was the optimum concentration of LaCl3 to promote the photosynthesis of Vaccinium.