铝胁迫下北美车前和车前生长及叶绿素荧光特性的比较研究

Comparison of Growth and Chlorophyll Fluorescence Characteristics Between Plantago virginica and P.asiatica under Aluminum Stress

采用系列浓度AlCl3溶液(100、500、800、2 000 mg.L-1)进行处理,在处理后不同时间(0,10、20、30 d),测定北美车前(Plantago viriginica)和车前(P.asiatica)的生长及叶绿素荧光特征指数,旨在比较外来入侵种北美车前和同属本地种车前的生长及叶绿素荧光对铝胁迫响应的差异。结果表明,车前和北美车前的根冠比在轻度铝(Al3+=100 mg.L-1)处理下略有上升,在中度(Al3+=500 mg.L-1)以上铝浓度处理下开始显著下降;叶绿素a、b含量在轻度铝处理下变化不明显,随着铝浓度的增加和处理时间的延长呈现明显下降趋势;叶绿素荧光参数Fv/Fm、ΦPSⅡ及Fv/Fo值在低浓度铝的短时间处理下略有上升,随着铝浓度的升高和处理时间的延长则明显下降。结果表明铝胁迫对上述两种植物的生长和叶绿素荧光参数均有一定影响,但北美车前各参数的下降幅度小于车前,表现出比车前更为耐铝的生理特性。

The present study is aimed at comparing the differences in growth responses and chlorophyll fluorescence characteristics between exotic invasive species Plantago virginica and native species P.asiatica under various concentrations of Al3＋ stress（100,500,800 and 2 000 mg·L^-1） along with different durations（0,10,20 and 30 d）.The results showed that root/shoot ratio increased slightly under low concentration of aluminum（100 mg·L^-1） and began to decrease significantly at over moderate concentration（500 mg·L^-1）;leaf chlorophyll a and chlorophyll b showed less change under low concentration of aluminum,but decreased obviously with the increases in Al3＋ concentration and treatment duration.Measurements of chlorophyll fluorescence parameters revealed that Fv/Fm,ΦPSⅡ and Fv/Fo increased slightly under low concentration of aluminum,and decreased obviously with the increases in Al3＋ concentration and duration.The decreases in root/shoot ratio,chlorophyll a and chloraphyll b,Fv/Fm,ΦPSⅡ and Fv/Fo of P.virginica was less than those of P.asiatica,indicating that the exotic invasive P.virginica had greater potential to alleviate aluminum stress through the mechanism of physiological defense,compared with the native P.virginica.