The impact of spring wheat species and sowing density on soil biochemical properties, content of secondary plant metabolites and the presence of Oulema ssp.

The physical and chemical properties of the soil are important factors influencing the yield of crops. One of the agrotechnical factors influencing the biochemical properties of soil is sowing density. It affects the yield components, light, moisture and thermal conditions in the canopy and the pressure of pests. Secondary metabolites, many of which are known to act as a defense mechanism against insects, are of importance in the interaction between the crop and abiotic and biotic factors of the habitat. To the best of our knowledge, the studies conducted so far do not sufficiently reveal the impacts of the wheat species and the sowing density, together with the biochemical properties of the soil, on the accumulation of bioactive ingredients in the crop plants, and the subsequent impacts on the occurrence of phytophagic entomofauna in various management systems. Explaining these processes creates an opportunity for more sustainable development of agriculture. The study aimed to determine the effect of wheat species and sowing density on the biochemical properties of the soil, concentrations of biologically active compounds in the plant and the occurrence of insect pests in organic (OPS) and conventional (CPS) production systems. The research was conducted on spring wheat species (Indian dwarf wheat-Triticum sphaerococcum Percival and Persian wheat-Triticum persicum Vavilov) grown in OPS and CPS at sowing densities 400, 500, 600 (seeds m-2). The following analyzes were performed: (i) soil analysis: the activity of catalases (CAT), dehydrogenases (DEH), peroxidases (PER); (ii) plant analysis: total phenolic compounds (TP), chlorogenic acid (CA), antioxidant capacity (FRAP); (iii) entomological analysis of the number of insects-Oulema spp. adults and larvae. Performing analyzes in such a wide (interdisciplinary) scope will allow for a comprehensive understanding of the soil-plant-insect biological transformation evaluation. Our results showed that an increase in soil enzyme activity caused a decrease in TP contents in the wheat grown the OPS. Despite this, both the content of TP and the anti-oxidative activity of the ferric reducing ability of plasma (FRAP) were higher in these wheats. Bioactive compound contents and FRAP were most favoured by the lowest sowing density. Regardless of the production system, the occurrence of the Oulema spp. adults on T. sphaerococcum was the lowest at a sowing density of 500 seeds m-2. The occurrence of this pest's larvae was lowest at a sowing density of 400 seeds m-2. Research on bioactive compounds in plants, biochemical properties of soil and the occurrence of pests make it possible to comprehensively assess the impact of the sowing density of ancient wheat in the ecological and conventional production system, which is necessary for the development of environmentally sustainable agriculture.

The role of an urban park's tree stand in shaping the enzymatic activity, glomalin content and physicochemical properties of soil.

Soil enzymes play a key role in the circulation of nutrients and the functioning of the ecosystem. The aim of the study was to assess how the tree species of urban agglomerations affect soil quality and enzymatic activity (dehydrogenases DEH, catalase CAT, alkaline AlP and acid AcP phosphatase, protease PR, ß-glucosidase GLU, and urease UR). To this end, soil samples were taken from beneath nine park trees. The risk of soil contamination by selected heavy metals (Pb, Ni, Cd) was also investigated against the background of the selected physicochemical properties. Enzyme activity results were used to calculate multi-parametric indices of soil quality: availability factor (AF), enzymatic pH indicator (AlP/AcP), biological index of fertility (BIF), geometric mean (GMea), alternation index (Al3), biochemical soil activity (BA16 and BA17). The results showed statistically significant differences in physicochemical and enzymatic properties of soil depending on tree species. Correlation analysis showed that the content of total organic carbon (TOC), total nirogen (TN), total phosphorus (TP) and humus (OM) in soil significantly influenced the activity of the studied enzymes and glomalin content. AF coefficient values (1.84%-18.19%) suggest that the bioavailability of available phosphorus (AP) was sufficient. The Pb, Ni, Cd content results were found to be low and did not exceed the permissible concentrations. DEH, CAT and AlP activity were highest under common hawthorn, and AcP, GLU and PR under northern white cedar. The calculated enzymatic indicators proved to be a sensitive and accurate indicator of the dynamics of changes taking place in the city park soil. Based on the results, an attempt can be made to assess the planning of sustainable development of studied areas of urban parks.

Assessment of selected heavy metals and enzyme activity in soils within the zone of influence of various tree species.

The study aimed to evaluate the total content and bioavailable forms of Zn, Cu, Pb and Ni and enzymatic activity (nitro reductase and peroxidases) in the mineral levels of surface soils within the zone of influence of various tree species. The conducted variance analysis confirmed the significant impact of the studied tree habitats on the total content and bioavailable forms of metals and on enzymatic activity. The total content of analysed metals were low and in no case exceeded the possible concentrations. The high bioavailability (AF %) values calculated for habitats of different species compositions (of 53.78% for Zn, 76.82% for Cu, 60.81% for Pb and 44.72% for Ni) may pose a risk of accumulation of these metals in plants. A significant correlation was found between nitrate reduction activity and Pb content (r = 0.510) and Cu (r = 0.678). Principal component analysis allowed two principal components to be distinguished (PC1 and PC2) that accounted for 60.95% of the total change in variance.

Antioxidant defence barrier of great tit Parus major nestlings in response to trace elements.

Metals can have direct and indirect effects on the generation of reactive oxygen species in wild birds. The aim of this work has been to examine the effect of exposure to trace metals (copper Cu, iron Fe, cobalt Co, manganese Mn) on oxidative stress biomarkers such as lipoperoxidation TBARS and level of superoxide dismutase SOD, catalase CAT, and reduced glutathione GSH in the livers and kidneys of great tit Parus major nestlings (n = 165, 63 broods) living in polluted environments associated with soda plants and agricultural activities (Kujawy region) and from a reference site (Tuchola Forest), both in the north of Poland. As we predicted, the level of TBARS in both organs of chicks from polluted areas was higher than in those from reference site. This could be connected with Fe concentrations, particularly in areas adjacent to soda plants (livers Rs = 0.49, p < 0.002; kidneys Rs = 0.69, p < 0.001). We also showed differences in the level of antioxidants depending on the environment. CAT activity was higher in nestlings from Kujawy than in those from Tuchola. Meanwhile SOD activity (both organs) and GSH levels (kidneys) were lower in the polluted area compared to the reference site. Concentrations of Cu, Fe, Co, and Mn may play a role in regulating the antioxidant system components' activity.

The effect of pro-ecological procedures and insect foraging on the total content of phenol compounds in winter wheat.

In laboratory conditions, the effect of pro-ecological procedures (application of effective microorganisms and Asahi SL biostimulator) and foraging by insects [cereal leaf beetle (Oulema melanopa L.) and bird cherry-oat aphid (Rhopalosiphum padi (L.)] on the total content of phenolic compounds in winter wheat, was studied. Correlations between the total content of phenolic compounds (determined by the Folin-Ciocalteau colorimetric method) expressed as the amount of pyrogallol in wheat plants: undamaged, damaged by O. melanopa, damaged by R. padi, the length of feeding scar left by cereal leaf beetle and the number of pricks made by actively feeding insects of bird cherry-oat aphid were analysed. The wheat was treated by EM inoculant and a biostimulator. The mode of application of the preparations used had a significant effect on level the total phenolic compounds in the undamaged wheat and the wheat exposed to foraging by the above-mentioned insects. The plants not exposed to insects foraging contained greater amounts of phenolic compounds than those exposed to the insects. The correlation between the total content of phenols in the wheat damaged by the insects in the 'no-choice' conditions, proved insignificant.

Fusarium infection in maize: volatile induction of infected and neighboring uninfected plants has the potential to attract a pest cereal leaf beetle, Oulema melanopus.

Fusarium infection of maize leaves and/or roots through the soil can stimulate the emission of volatile organic compounds (VOCs). It is also well known that VOC emission from maize plants can repel or attract pests. In our experiments, we studied VOC induction responses of Zea mays L. ssp. mays cv. 'Prosna' having Fusarium infection (mix of four species) in leaves or roots, then tested for VOC induction of uninfected neighboring plants, and finally examined wind-tunnel behavioral responses of the adult cereal leaf beetle, Oulema melanopus L. (Chrysomelidae: Coleoptera) behavior to four induced VOCs. In the first part of our experiment, we confirmed that several green leaf volatiles (GLVs; (Z)-3-hexenal, (E)-2-hexenal, (Z)-3-hexen-1-ol, (E)-2-hexen-1-ol, (Z)-3-hexen-1-yl acetate, 1-hexyl acetate), terpenes (ß-pinene, ß-myrcene, Z-ocimene, linalool, ß-caryophyllene), and shikimic acid pathway derivatives (benzyl acetate, methyl salicylate, indole) were positively induced from maize plants infected by Fusarium spp. The quantities of induced VOCs were higher at 7d than 3d post-infection and greater when plants were infected with Fusarium on leaves rather than through soil. In the second part of our experiment, uninfected maize plants also showed significantly positive induction of several VOCs when neighboring an infected plant where the degree of induction was negatively related to the distance from the infected plant. In the third part of our experiment, a Y-tube bioassay was used to evaluate upwind orientation of adult cereal leaf beetles to four individual VOCs. Female and male O. melanopus were significantly attracted to the GLVs (Z)-3-hexenal and (Z)-3-hexenyl acetate, and the terpenes linalool and ß-caryophyllene. Our results indicate that a pathogen can induce several VOCs in maize plants that also induce VOCs in neighboring uninfected plants, though VOC induction could increase the range at which an insect pest species is attracted to VOC inducing plants.

Cereal crop volatile organic compound induction after mechanical injury, beetle herbivory (Oulema spp.), or fungal infection (Fusarium spp.).

Herbivory, mechanical injury or pathogen infestation to vegetative tissues can induce volatile organic compounds (VOCs) production, which can provide defensive functions to injured and uninjured plants. In our studies with 'McNeal' wheat, 'Otana' oat, and 'Harrington' barley, plants that were mechanically injured, attacked by either of two Oulema spp. (melanopus or cyanella) beetles, or infected by one of the three Fusarium spp. (graminearum, avenaceum, or culmorum), had significant VOC induction compared to undamaged plants. Mechanical injury to the main stem or one leaf caused the induction of one green leaf volatile (GLV) - (Z)-3-hexenol, and three terpenes (ß-linalool, ß-caryophyllene, and α-pinene) with all three grasses; wheat and barley also showed ß-linalool oxide induction. The blend of induced VOCs after Fusarium spp. infestation or Oulema spp. herbivory was dominated by GLVs ((Z)-3-hexenal, (E)-2-hexenal, (E)-2-hexenol, (Z)-3-hexenyl acetate, and 1-hexenyl acetate) and ß-linalool and ß-caryophyllene; beetle herbivory also induced (E)-ß-farnesene. Different ratios of individual VOCs were induced between the two Oulema spp. for each cereal grass and different ratios across the three cereals for each beetle species. Also, different ratios of individual VOCs were induced between the three Fusarium spp. for each cereal grass and different ratios across the three cereals for each fungal pathogen species. Our results are preliminary since we could not simultaneously measure VOC induction from controls with each of the ten different injury treatments for each of the three cereals. However, the comparison of mechanical injury, insect herbivory, and fungal infection has not been previously examined with VOC responses from three different plant species within the same family. Also, our work suggests large qualitative and quantitative overlap of VOC induction from plants of all three cereals having beetle herbivory injury when compared to infection injury from necrotrophic fungal pathogens.