Fluorescence traits of invasive species in Lithuania

Abstract

Some worldwide invasive plant species spread successfully throughout natural and semi-natural habitats in Lithuania. Accordingly, measures have been strongly recommended to prevent the introduction of such species and their spreading to new areas, or to manage unwanted populations. The proliferation of invasive species abundancy in new environments indicates a good supply of resources at physiological levels, viz. photosynthesis. Therefore, the assessment of chlorophyll fluorescence as a non-invasive intrinsic investigation of photosynthesis can give detailed information and be applied for understanding of invasive species adaption to a new environment. The research was aimed at the evaluation of the fluorescence parameters of invasive plant species (Fallopia sachalinensis (F sach), Heracleum sosnovskyi (H sasn), Rumex confertus (R conf)), the indicators of their physiological acclimation to a new environment, by identifying traits that could explain their success in terms of invading new territories. Fluorescence gains were measured in situ at the different growth stages during the vegetation period of invasive species in 10 replications using a light-adapted pulse-amplitude modulation method. The main parameters of the photosynthetic system II (PSII), e.g., fluorescence yield (Fs) in the light and maximal fluorescence (Fms) during the light flash were recorded in and used to determine the quantum yield of electron transport (Y). Between investigated species significantly (p<0.000) higher means of Fs, the index of photosynthetic excitation in light, and Fms, the index of efficiency of PSII, were observed in light-adapted leaves of H sosn (412.7 and 399.32 μmol m-2 s-1) and F sach (399.32 and 1726.90 μmol m-2 s-1). [...]