3种入侵植物叶绿素荧光特性的研究

Study on the Chlorophyll Fluorescence Characteristics of Three Invasive Plants

[目的]研究入侵植物的叶绿素荧光特性。[方法]以3种入侵植物水葫芦、大薸和空心莲子草为材料,利用调制叶绿素荧光技术对其叶绿素荧光特性进行比较。[结果]结果表明,在弱光下(200μmol/m2.s)空心莲子草实际光合效率(PSII)和快速光曲线的初始斜率(α)都高于大薸和水葫芦,但强光下(800μmol/m2.s)空心莲子草的PSII和相对电子传递速率(rETR)受到显著抑制,大薸抑制程度较低,而水葫芦的耐受性最强。通过快速光曲线发现,在变化的光强环境中,水葫芦的适应能力最好,大薸次之,而空心莲子草最差。强光下水葫芦和大薸非光化学淬灭(NPQ)的主要组分是能态淬灭(qE),而空心莲子草的主要组分是qE和状态转换淬灭(qT)。3种入侵植物中水葫芦的适应能力最强,大薸次之,空心莲子草最低。空心莲子草尽管在强光下受到了损伤,但仍具备较高的光保护能力来助其"过冬"。这些特性可能与植物的入侵性有密切关系。[结论]该研究为探讨入侵植物维持能量平衡的能力与入侵性的关系提供参考。

[ Objective ] The purpose aimed to study chlorophyll fluorescence characteristics of three invasive plants. [ Method ] The chlorophyll fluorescence characteristics of three invasive plants which were Eichhornia crassipes, Pistia stratiotes and Alternanthera philoxeroides were measured by modulated-chlorophyll fluorometer. [ Result ] The results showed that in low light （200 μmol/m^2·s）, the effective PS II quantum yield （PSII） and the original slope of rapid light curve （α） of A. philoxeroides was higher than that of E. crassipes and P. stratiotes. However, in high light （800 μmol/m^2·s）, PSII and relative electron transfer rate （rETR） of A. philoxeroides were inhibited obviously than in low light. E. crassipes showed highest activity among the three plants in high light. The results of rapid light curves also showed that E. crassipes had the best adaptability to changing light environment. Under high light, the energy-dependent quenching （qE） played key role of heat dissipation in E. crassipes and P. stratiotes, while in A. philoxeroides both qE and state transition dependent quenching （qT） played importment role in photoprotection. E. crassipes had the best adaptability to changing light enviromnent, and P. stratiotes took the second place among three plants. Although A. philoxeroides were photoinhibited in high light, it still could protect itself through increasing non-photochemical quenching. These characteristics might give useful information for the explanation of the mechanism of plant invasion. [ Conclusion] This research will provide the references for discussing the relationship between the ability of maintaining energy balance and plant invasion.