Chlorophyll a fluorescence gives information about the plant physiological status due to its coupling to the photosynthetic electron transfer chain and to the further biochemical processes. Environmental stresses, which acts synergistically, disturbs the photosynthesis. The OJIP test, elaborated by Strasser and co-workers, enables comparison of the physiological status of plants grown on polluted vs. control areas. The paper shows that the Chl a measurements are very useful tool in evaluating of heavy metal ions influence on perennial grasses, tested as potential phytoremediators. Among 5 cultivars tested, the highest concentration of Cd and Zn ions, not associated with the yield reduction, was detected in the biomass of tall fescue cv. Rahela. Chl a fluorescence interpreted as double normalized curves pointed out Rahela as the outstanding cultivar under the HM ions stress.
Endophytic fungi live their whole life within host tissues usually without any visible symptoms. Their vertical transmission (seed-plant-seed) has been well described and documented. However, horizontal transmission (plant-plant) needs more clarification. The aim of this study was to assess the extent to which endophytes move vertically in ecotypes of perennial ryegrass and whether there is evidence for the horizontal transmission of endophytes. Ecotypes from grasslands in Poland were collected in the form of living plants and used for vertical transmission analysis. Plants, the seed collected from these plants and plants grown from this collected seed were tested for endophytic infection. Provided that all produced seeds were viable and able to germinate and produce seedlings, the vertical transmission of Neotyphodium endophytes in perennial ryegrass ecotypes was nearly complete. For the horizontal transmission experiment, endophyte-hosting plants (E+) and endophyte-free plants (E-) of four cultivars were planted in the field in close proximity on small plots that were frequently mown. These studies revealed that after 7 months of growth next to E+ plants, the characteristic Neotyphodium spp. mycelia were found in E- plants, which was especially true for plants growing in close proximity to the infected plants. The occurrence of horizontal transmission of endophytes has not been previously demonstrated.
As a fuel, biomass differs in its properties from fossil fuels and acquisition thereof for energy purposes is limited; hence, the ongoing search for new bioenergetically useful plants. The article presents the results of physical and chemical analyses of seven species of perennial grasses: tall wheatgrass, tall wheatgrass ‘Bamar’, brome grass, tall fescue ecotype, reed canary grass, giant miscanthus, and sorghum. The research involved technical and elemental analysis as well as analysis of the ash composition performed in order to determine their potential use for combustion process. The measurement results were compared with those obtained for hard coal and agricultural biomass, which is widely used in the energy industry. The results suggest that perennial grasses can successfully be combusted with similar performance to coal if burned in appropriate combustion installations.