Miłosz Tkaczyk

Phosphite fertilisers as inhibitors of Hymenoscyphus fraxineus (anamorph Chalara fraxinea) growth in tests in vitro

Abstract This study is designed to test the potential for reducing the growth of the mycelium of the fungus Hymenoscyphus fraxineus (anamorph Chalara fraxinea) by using phosphite preparations at various concentrations in vitro. The study shows that adding pure phosphite to potato dextrose agar media inhibits the development of the fungus, but if the preparation is applied in the form of ammonium phosphite (Actifos), the growth of fungus will be accelerated. Probably the addition of nitrogen contained in the product Actifos has positive effect on the mycelial growth, but pure phosphite restricts its development. These studies are preliminary and only show the potential use of phosphite to reduce the development of H. fraxineus; however, to completely confirm its operation, further research is needed in this area.

Pine sawdust as stimulator of the microbial community in post-arable afforested soil

ABSTRACT Sawdust and wood residues are considered to be stimulators of microbiological change in soil and could be used in post-arable sites designed for afforestation. In this study, we discuss changes in bacteria numbers within selected groups in relation to soil type (arable and forest) and method of sawdust application. Sawdust was spread along planting rows and mixed with the soil or put directly under roots of planted seedlings. Applying sawdust under the roots increased the number of cellulolytic bacteria in all experimental treatments. On post-arable soil, adding sawdust in rows increased the number of copiotrophic bacteria and reduced the number of fluorescent bacteria and actinomycetes (ACT). In control forest soils, the number of copiotrophic, oligotrophic and spore-forming bacteria decreased simultaneously with increased ACT in all treatments. The number of fluorescent bacteria increased when sawdust was applied on forest sites under planted trees and decreased when sawdust was spread in planting rows. Oligotrophic bacteria also decreased in the latter case. We present a list of bacteria identified by DNA – 16S rRNA gene sequences. Adding sawdust to arable soils significantly changed the quantitative and qualitative composition of microbial communities.

The use of phosphates in forestry

Abstract Phosphite preparations are now an important alternative in plant protection against new, invasive pathogens of the genus Phytophthora and/or Pythium. It is crucial to intervene when alien, invasive oomycetes are carried to plantations or forest stands and attack fine roots via zoospores. The aim of this paper was to demonstrate the possibility of phosphite application to induce resistance to tree pathogens. Phosphate-based fertilizers have been used successfully in nurseries, where application is relatively easy by means of foliar sprays. the traditional fungicides, which are effective in combating fungi, however, fail to control oomycetes. Instead, they mask the disease, which, in turn, causes serious damage to seedlings after they have been planted in a suitable environment. Moreover, the number of effective fungicides available for forest plant protection has continued to decrease in the last decade. The effectiveness of the chemicals is reduced due to their frequent use and their similarity in terms of the active compound or the mechanism of action. Given the low diversity of active compounds, it is necessary to monitor the development of resistance of pathogens to fungicides by means of molecular biology (sequencing and quantitative PCR). Minimising the undesired side effects of chemicals on both, mycorrhizal fungi and pathogens can be achieved by strict adherence to rigorous security measures and, where possible, frequently changing the active compounds to alternatives such as phosphites. The significance of phosphate and phosphite uptake by trees is still a matter of debate, especially under field conditions. Nevertheless, phosphites are environmentally friendly compounds, which constitute an alternative or complement to the traditional chemicals (in accordance with the Directive on Integrated Plant management).

Phytophthora quercina infections in elevated CO2 concentrations

Abstract In the last decades, a new wave of oak decline has been observed in Poland. The most important pathogenic organisms involved in this phenomenon are probably soil-borne pathogens Phytophthoragenus, especially P. quercina. In this work, we sought to test the influence of elevated CO2 concentration on the susceptibility of oaks (Quercus robur L.) to infection by P. quercina. In order to test the susceptibility of oak fine roots to infection, we applied phosphite-based fertiliser Actifos in 0.6% concentration. One-year-old oak seedlings were grown for one year in greenhouse with either an ambient atmosphere (400 ppm CO2) or an elevated (800 ppm) concentration of CO2. Oaks grown at the elevated CO2 concentration developed longer shoots as proved by statistically significant differences. However, there was no difference in the development of root systems. The application of Actifos had a positive significant effect on the development of shoots and the surface area of fine roots under the elevated CO2 concentration.

Preliminary analysis of the forest health state based on multispectral images acquired by Unmanned Aerial Vehicle

Abstract The main purpose of this publication is to present the current progress of the work associated with the use of a lightweight unmanned platforms for various environmental studies. Current development in information technology, electronics and sensors miniaturisation allows mounting multispectral cameras and scanners on unmanned aerial vehicle (UAV) that could only be used on board aircraft and satellites. Remote Sensing Division in the Institute of Aviation carries out innovative researches using multisensory platform and lightweight unmanned vehicle to evaluate the health state of forests in Wielkopolska province. In this paper, applicability of multispectral images analysis acquired several times during the growing season from low altitude (up to 800m) is presented. We present remote sensing indicators computed by our software and common methods for assessing state of trees health. The correctness of applied methods is verified using analysis of satellite scenes acquired by Landsat 8 OLI instrument (Operational Land Imager).

Effect of CO2 enhancement on beech (Fagus sylvatica L.) seedling root rot due to Phytophthora plurivora and Phytophthora cactorum

Abstract Global climate change is associated with higher concentrations of atmospheric carbon dioxide (CO2). The ongoing changes are likely to have significant, direct or indirect effects on plant diseases caused by many biotic agents such as phytopathogenic fungi. This study results showed that increased CO2 concentration did not stimulate the growth of 1-year-old beech Fagus sylvatica L seedlings but it activated pathogenic Phytophthora species (P. plurivora and P. cactorum) which caused significant reduction in the total number of fine roots as well as their length and area. The results of the greenhouse experiment indicated that pathogens once introduced into soil survived in pot soil, became periodically active (in sufficient water conditions) and were able to damage beech fine roots. However, the trees mortality was not observed during the first year of experiment. DNA analyses performed on soil and beech tissue proved persistence of introduced Phytophthora isolates.

Genetic variability and health of Norway spruce stands in the Regional Directorate of the State Forests in Krosno

Abstract The study was conducted in 2015 in six spruce stands situated in different forest districts administratively belonging to the Regional Directorate of State Forests in Krosno. Each spruce population was represented by 30 trees and assessed in terms of their current health status. Genetic analyses were performed on shoot samples from each tree using nine nuclear DNA markers and one mitochondrial DNA marker (nad1). The health status of the trees was described according to the classification developed by Szczepkowski and Tarasiuk (2005) and the correlation between health classes and the level of genetic variability was computed with STATISTICA (α = 0.05). Nuclear DNA analyses revealed a low level of genetic variability among spruce populations (only 3% of the total genetic variation (FST = 0.028) and a high variability within populations (97%). The total heterozygosity in all stands (HT) was calculated as 0.646. Based on UPGMA analysis, the most genetically similar populations are spruce stands in the Bieszczady National Park and the Ustrzyki Dolne Forest District, which have the smallest genetic divergence of all populations (DN = 0.0165). Our analysis of the mitochondrial gene nad1 revealed the presence of six different haplotypes ‘a’, ‘a1’, ‘b’, ‘c’, ‘d’ and ‘d1’. Comprising 56% of all haplotypes, ‘a’ was the most common showing a predominant impact on spruce migration from the Carpathian area. The analysis based on mitochondrial markers (by Nei) revealed a heterozygosity of 0.525. Based on the observations of disease symptoms, 29% of the trees belong to health class 1, 30% to class 2, 28% to class 3 and class 4 contains 13% of trees. The comparison between health status and the level of genetic variation in the analysed stands showed a positive correlation. Spruce stands with better health were also characterised by a greater degree of genetic variability. Since most of the investigated spruce populations shared the mitochondrial haplotype ‘a’, we have ascertained their Hercynian–Carpathian origin. Only one stand (Cisna) had a high frequency (43.3%) of the Nordic haplotype ‘c’ suggesting that this provenance is derived from the Baltic post-glacial refugium of P. abies in europe.

Four different Phytophthora species that are ableto infect Scots pine seedlings in laboratory conditions

Abstract To investigate susceptibility of young Scots pine seedlings to four Phytophthora species: Phytophthora cactorum, Phytophthora cambivora, Phytophthora plurivora and Phytophthora pini; seven-day-old seedlings of Scots pine (15 seedlings per experiment) were infected using agar plugs of the respective species. Control group also consisted of 15 seedlings and was inoculated with sterile agar plugs. Results unambiguously show that after 4.5 days, all seedlings show clear signs of infection and display severe symptoms of tissue damage and necrosis. Moreover, three and two seedlings in the P. cactorum and P. cambivora infected seedlings groups, respectively, collapsed. The length of largest necrosis measured 13.4±3.90 mm and was caused by P. cactorum. To rule out any putative contamination or infection by secondary pathogens, re-isolations of pathogens from infection sites were performed and were positive in 100% of plated pieces of infected seedlings. All re-isolations were, however, negative in the case of the control group. Detailed microscopic analyses of infected tissues of young seedlings confirmed the presence of numerous Phytophthora species inside and on the surface of infected seedlings. Therefore, our results suggest Phytophthora spp. and mainly P. cactorum and P. cambivora as aggressive pathogens of Scots pine seedlings and highlight a putative involvement of these species in the damping off of young Scots pine seedlings frequently observed in forest nurseries.

Slow sand filtration for elimination of phytopathogens in water used in forest nurseries

Irrigation water from natural sources can be contaminated by fungi, Oomycota, or bacteria capable of causing serious diseases in seedlings in forest nurseries. Slow sand filtration (SSF) is a cost-effective technique for water decontamination prior to irrigation. The aim of the current study was to assess the effectiveness of SSF as a means of eliminating plant pathogens including Pythium sterilum, Fusarium solani, Xanthomonas campestris, Pseudomonas syringae pv. Syringae and Rhizobium radiobacter from the lake water source used for irrigation. The applied SSF was effective in removing 80–90% of fungal and Oomycota inoculum as well as 70% of the bacteria in the investigated water. Therefore, SSF represents a practical step to lowering the use of pesticides during production of planting stocks in forest nurseries and a valuable element in an integrated plant protection system.

Analiza zawartości fosfonianów w materiale roślinnym

Praca wykonana w ramach projektu badawczego Life 11 ENV/PL/459 PROJECT ACRONIM: HESOFF „Evaluation of the health state of forests and an effect of phosphite treatments with the use of photovoltaic SLE”, finansowanego przez The European Community according to LIFE + Program and by the National Fund for Environmental Protection and Water Management in Poland.