G. Mastalerczuk

Gas-exchange parameters and morphological features of festulolium (Festulolium braunii K. Richert A. Camus) in response to nitrogen dosage

The response of some photosynthetic parameters (CO2 assimilation, transpiration rate, stomatal conductance, intercellular CO2 concentration, water-use efficiency, and chlorophyll content), shoot development, and the morphological features of the root system to differentiated conditions of nitrogen supply was tested in festulolium (Festulolium braunii K. Richert A. Camus) varieties (Felopa and Sulino). Nitrogen fertilization with no nitrogen added [0 g(N)], single dosage [0.23 g(N)], and double dosage [0.46 g(N)] per pot and per year was applied. Lack of nitrogen resulted in formation of longer and finer roots and lowered chlorophyll content, CO2 assimilation, and water-use efficiency, resulting in lower dry matter accumulation. Application of both dosages of nitrogen resulted in improved aboveground features, while root features were enhanced without nitrogen fertilization. Dependence between physiological parameters and morphological traits was significant and positively correlated in the case of the aboveground parts of plants and negatively correlated to the belowground parts.

Photosynthetic efficiency and survival of Dactylis glomerata and Lolium perenne following low temperature stress

Resistance to low temperature is crucial for overwintering crops. In this work we compared the resistance to low temperature treatment of some varieties of two forage grass species Dactylis glomerata L. and Lolium perenne L. in order to elucidate the reason for the better resistance found in some species. The variety Amila of D. glomerata and Diament of L. perenne were more tolerant to low temperature stress during the emergence and tillering phases as compared to the varieties Amera and Gagat. The improved tolerance and ability for recovery after stress were associated with the better recovery of photosynthetic efficiency of these varieties and better survival of their shoots after low temperature stress.

Fluorescence of chlorophyll as a tool to assess the degree of eutrophication of aquatic ecosystems on the example of ponds in the area of Raszyn commune

The currently available methods for the assessment of the eutrophication degree are expensive, time-consuming and require advanced laboratory equipment and knowledge. The aim of this work was to determine a simple and economically justified method of monitoring the effects of eutrophication of water in the agricultural area and linking the results of monitoring physicochemical parameters of water with chlorophyll fluorescence as a potential health risk on the basis of established alarm levels. The research was conducted in water reservoirs located in the rural area, differing in the intensity of exploitation of adjacent areas: located in the vicinity of intensively cultivated areas and in the protected area of the nature reserve. The work determined the efficiency of the photosynthetic apparatus of algae and physicochemical properties of water. The studies have shown that the increase in the chlorophyll fluorescence intensity is associated with an raised biogenic load and an increased occurrence of chlorophyll-containing micro-fractions. The results indicate the possibility of using chlorophyll fluorescence measurements to assess the degree of water eutrophication. The presented method can be used for a non-invasive, quick and precise assessment of the physiological status of water ecosystems in rural areas, particularly vulnerable to the eutrophication processes.