First descriptions of fundatrix morphs of Pterocomma tremulae Börner, 1940 and P. pilosum Buckton, 1879 are presented with some taxonomical comments on their morphological traits. The key to the known fundatrices of European representatives of the genus Pterocomma is provided.
The influence of mycorrhiza with Hebeloma crustuliniforme on plant growth, leaf water potential, leaf gas exchange and chlorophyll content in 3 poplar varieties (P. petrowskyana, P. deltoides cv. Plantierens, P. balsamifera) were investigated. After 11 weeks of plant growth mycorrhizal structures (frequency of mycorrhiza - FF%, intensity of the mycorrhizal colonization - MC% were observed in plant roots belonging to the treatment (M). No statistically significant differences were observed in the frequency of mycorrhiza (F%) and intensity of the mycorrhizal colonization (MC%) in plant roots of the treatment M between the examined poplar cultivars. The frequency of mycorrhiza (FF%) was high, and it reached about 75%, while the intensity of the mycorrhizal colonization (MC%) by fungi hyphae was slightly lower and equaled to from 49 to 58%. For plants, exposed to the inoculation with mycorrhizal fungi, advantageous and statistically significant changes in the measured physiological traits were observed. In this research advantageous differences in reactions between inoculated and non-inoculated poplar cultivars were observed, which was shown in the measurements of some physiological traits. Compared to the control plants (C), in the case of plants of the treatment (M) greater increase in plant height (∆Н), increase in chlorophyll content (SPAD), higher values of water potential (Ψ), and increase - in photosynthesis rate (Pn), stomatal conductance (gs) and water use efficiency (WUE), and decrease in transpiration rate (E), were observed. Although those differences were relatively small, we may presume that if they occur through a longer period they may become more distinct e.g. as a greater increase in height in the inoculated plants.
The health status of 6−16−year−old poplars (mostly Populus robusta) in the sanitary protection zones around Legnica and Głogów copper mills (SW Poland) is described. The health of the poplars was assessed as a frequency of trees with symptoms of stem canker and occurrence of virus diseases on leaves. Fungi were isolated from 24 samples of canker wood (20×20×20 cm each) in five afforested complexes and then identified on the basis of colony morphology and sporulation on PDA and SNA after 40 days of incubation. Cankers occurred on <5−95% of poplar trees. Poplar mosaic virus was observed sporadically in collections of P. robusta, P. balsamifera and P. gerlica. The canker wood was colonized by 20 species of facultative pathogens. Acremonium pteridii, Exophiala sp. and Gibberella baccata were the most common and frequent (in 4−5 complexes). Aureobasidium pullulans, Epicoccum nigrum and Fusarium solani occurred in 3−4 complexes. Alternaria alternata, Cadophora fastigiata, Didymella molleriana, Fusicolla aquaeductuum, Gibberella avenacea, Graphium sp., Leptosphaeria maculans, Nectria inventa, Phoma herbarum, P. minutella, Sarocladium strictum, Trichosporon ovoides and Valsa sordida were less frequent and often occurred only locally. The fungi recorded may serve as indicators of the vitality and health status of trees in industrial zones. The best approach to eliminate the risk of colonization by pathogens is to maintain trees in a state of vigorous growth. Management practices that promote good growth include fertilization, watering during drought, avoidance of unnecessary wounding of trunk and roots, and using correct pruning procedures.