Changes in root-associated fungal communities in Triticum aestivum ssp. spelta L. and Triticum aestivum ssp. vulgare L. under drought stress and in various soil processing.

Plant roots are inhabited by an enormous variety of microorganisms, including fungi, which can control the growth as well as regulate the health of the host plants. The mycobiome composition of the roots of wheat plants, especially spelt, under drought stress has been rarely investigated. Therefore, the aim of the present study was to examine the composition of fungal communities in the root endosphere and rhizosphere of three Triticum aestivum ssp. spelta L. cultivars and one Triticum aestivum ssp. vulgare L. cultivar, grown under drought and controlled conditions in different soil preparations. Culture-dependent fungal community profiling was performed to examine the impact of rhizocompartments (endosphere, rhizosphere), host genotype, watering status and different soil preparation on roots mycobiome structure. A total of 117 fungal strains, belonging to 22 genera, were found to colonize the internal and external parts of roots in T. aestivum ssp. spelta L. and T. aestivum ssp. vulgare L. cultivars. The results showed that the part of root and soil preparation type significantly determined the mycobiome composition of wheat roots.

Growth and Photosynthetic Activity of Selected Spelt Varieties (Triticum aestivum ssp. spelta L.) Cultivated under Drought Conditions with Different Endophytic Core Microbiomes.

The role of the microbiome in the root zone is critically important for plants. However, the mechanism by which plants can adapt to environmental constraints, especially water deficit, has not been fully investigated to date, while the endophytic core microbiome of the roots of spelt (Triticum aestivum ssp. spelta L.) grown under drought conditions has received little attention. In this study, we hypothesize that differences in the endophytic core of spelt and common wheat root microbiomes can explain the variations in the growth and photosynthetic activity of those plants, especially under drought conditions. Our greenhouse experimental design was completely randomized in a 2 × 4 × 3 factorial scheme: two water regime levels (well-watered and drought), three spelt varieties (T. aestivum ssp. spelta L.: 'Badenstern', 'Badenkrone' and 'Zollernspelz' and one wheat variety: T. aestivum ssp. vulgare L: 'Dakotana') and three mycorrhizal levels (autoclaved soil inoculation with Rhizophagus irregularis, control (autoclaved soil) and natural inoculation (non-autoclaved soil-microorganisms from the field). During the imposed stress period, relative water content (RWC), leaf chlorophyll fluorescence, gas exchange and water use efficiency (WUE) were measured. Microscopic observations of the root surface through fungi isolation and identification were conducted. Our results indicate that 'Badenstern' was the most drought tolerant variety, followed by 'Zollernspelz' and 'Badenkrone,' while the common wheat variety 'Dakotana' was the most drought sensitive. Inoculation of 'Badenstern' with the mycorrhizal fungi R. irregularis contributed to better growth performance as evidenced by increased whole plant and stalk dry matter accumulation, as well as greater root length and volume. Inoculation of 'Zollernspelz' with arbuscular mycorrhizal fungi (AMF) enhanced the photochemical efficiency of Photosystem II and significantly improved root growth under drought conditions, which was confirmed by enhanced aboveground biomass, root dry weight and length. This study provides evidence that AMF have the potential to be beneficial for plant growth and dry matter accumulation in spelt varieties grown under drought conditions.

Can pyraclostrobin and epoxiconazole protect conventional and stay-green maize varieties grown under drought stress?

Risks associated with drought are increasing and are a global problem. Therefore, there is a need for new solutions for the safe production of food, while maintaining respect for the environment. Fungicides are designed to protect maize plants against disease, but some of the active substances used in preparations can also promote plant growth, which is known as the 'physiological effect'. However, there is a paucity of information as to how some of the 'new generation' fungicides act in stimulating grain yield in plants under abiotic stress, especially drought. Therefore, the effects of these products on conventional and stay-green maize varieties need to be better understood in order to reduce losses caused by droughts and to maximize production. In this study, the effect of a pyraclostrobin + epoxiconazole fungicide preparation on maize plants was evaluated at different times after spraying; during induced drought conditions and again during the regeneration process of the plants. The preparation was applied to 'KWS 1325' (conventional) and 'Ambrosini' (stay-green) varieties at the recommended dose, three times in greenhouse conditions. Plant gas exchange, plant water use efficiency, chlorophyll fluorescence and fresh and dry plant biomass were evaluated. The pyraclostrobin + epoxiconazole preparation increased stomatal conductance and photosynthesis intensity in the 'Ambrosini' plants. When maintained under a high light intensity, the variety used increased efficiency and exchanged excessive energy in the form of thermal energy to protect the maize leaf from light-induced damage under drought stress. Plant photosynthetic efficiency (ETR and Yield parameters) during drought stress and after regeneration was significantly higher in treated plants than in the controls. Thus, the beneficial effects on the physiology of the maize varieties grown under drought stress from the fungicide application are significant for farmers and growers.

The effect of sewage sludge and BAF inoculant on plant condition and yield as well as biochemical and microbial activity of soil in willow (Salix viminalis L.) culture as an energy crop.

Excessive amounts of sewage sludge produced in sewage treatment plants along with the ban on its storage and dumping require rapid solutions to the problem of sewage sludge management. An example of a rational and environmentally viable method may be provided by its application in agriculture and environmental management. The optimal solution is to use sludge as a fertiliser for industrial plants, including energy crops, that is, those not used in food production. For environmental reasons it is essential to control soil quality and condition following sludge application. Analyses of the residual effect of sewage sludge and bacteria, actinobacteria, fungi microbial inoculant (BAF) on selected physiological parameters of plants and microbial activity of soil were conducted in the years 2013-2015 on experimental fields of the Poznan University of Life Sciences. The results indicate that the application of sewage sludge increased yields and improved selected photosynthesis activity and biometric traits of willow. Among the tested combinations the best results were obtained following the application of sewage sludge combined with the BAF medium microbial inoculant. Similar dependencies were observed when evaluating soil microbial activity.

Chemical Profile and Antioxidant Activity of Trollius Europaeus under the Influence of Feeding Aphids.

The influence of stress factors on a plant may lead to worse functioning of the plant and the loss of its crop. The effect of Aulacorthum solani feeding on Trollius europaeus with regard to active compounds in the leaves was investigated in the study. The antioxidant activity of the leaves, the material on which the insects fed, was compared with that of the material that was not infested by the aphids. Stress level was evaluated on the basis of such physiological parameters as chlorophyll fluorescence and photosynthesis activity. An increase of 34.5% in the content of polyphenolic compounds, as compared to control, was demonstrated in the material exposed to the biotic stress caused by aphids. The content of phenolic acids was 28% higher while that of flavonoids rose by 25%. The increase in polyphenolic compounds augmented the antioxidant activity of the material.