Grapevines considered to be one of most important crops worldwide as well as in Greece. Grape’s Black rot disease caused by several mycotoxigenic species of Black Aspergilli section Nigri, is one of the most important pre- as well as post-harvest diseases of grapevines, while contaminated grape products and derivatives with Aspergillus mycotoxins may have an important impact on consumers health. Overall the aim of this project is the investigation of the population structure and the determination of the in vitro mycotoxigenic capacity of black Aspergilli species collected from conventional and organic growing systems. In detailed, asymptomatic grape berries were collected for two consecutive years (2018 & 2019) from organic and conventional grapevines originated from different regions all over the Greece. In total, 300 isolates of Aspergillus spp. were selected and identified by amplicon sequencing of three reference genes. More specifically, A. tubingiensis, A. uvarum, A. carbonarious and A. niger were identified as the casual agents of Black rot disease in Greece, while A. uvarum and A. tubingiensis considered to be the predominant species for 2018 and 2019, respectively. In addition, for both sampling years, higher frequencies of A. tubingiensis and A. uvarum were found in the organic and in the conventional grapevines, respectively. In vitro mycotoxin production (OTA, FB_2, FB₃ and FB₄) was evaluated in two selective media, while the analysis and the quantification were performed with LC/Q-TOF MS system. The analysis revealed significant high mycotoxin production, especially to the isolates originated from the conventional vineyards. In addition, A. carbonarious identified as the main OTA (0.02 to 16 μg/g) producer, while A. niger was the main producer of FB₂(5 to 35 μg/g), FB₄ and FB_6.

The objective of this study was to perform phytochemical screening, estimate total phenolics, flavonoids and to evaluate antioxidant potential of Tomborissa comorensis fruit. The dried and pulverized fruit of Tomborissa comorensis (150g) were extracted exhaustively by Soxhlet with increasing polarity of solvents (hexane, ethyl acetate and methanol). Folin-Ciocalteu reagent and aluminium chloride colorimetric methods were used to estimate total phenolic and flavonoid content of extracts. Three different methods namely 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, reducing power scavenging activity (FRAP) and total antioxidant capacity were used to determine in vitro antioxidant activity. Phytochemical screening concerns the presence of flavonoids in the ethyl acetate and methanol extracts and tannins only on the methanol extract. Total phenolic and flavonoids contents results are showed in a large dominance in methanol extract. All tests showed significant dose dependent antioxidant activities. The ethyl acetate extract shows the high activity in DPPH radical scavenging activity but in reducing power assay, it’s the methanol extract which manifested the high activity. The results of this study show that the fruit of T. comorensis is a rich source of phenolic compounds that can play an important role in preventing the progression of many diseases.

Nanotechnology provides unique opportunities for the development of novel nanotools in various fields, especially in agriculture. In terms of desired function, nanomaterials are proposed as environmentally acceptable substitutes that can lead to a green agricultural revolution. Among others, inorganic nanoparticles (INPs) stand at the first line. The advantage of INPs arises from their unique inherent physicochemical properties in combination with nanoeffects that classify them as nanofertilizers or nanopesticides. Thus, INPs have been found to enhance pesticide efficiency and provide crop productivity at low doses. Nanopesticides are considered less harmful for the environment because they are usually involved in the slow release of the active ingredient that is employed in less quantities of the formulate, compared to the conventional pesticides. Herein, INPs that are based on bioessential and bioactive elements, namely copper and zinc, have been prepared and tested as antifungal and nematicidal agents. Copper nanoparticles (Cu NPs), zinc oxide nanoparticles (ZnO NPs) and bimetallic nanostructures of CuZn and CuZn@ZnO NPs have been isolated through assisted microwave process and solvothermal method in the presence of polyols. Sizes were identified in a range of 20 to 40 nm while polyols serve as coatings to the INPs. Antifungal and nematicidal activity of NPs was studied in vitro against the phytopathogenic fungi Botrytis cinerea and Sclerotinia sclerotiorum as well as on the root-knot nematode Meloidogyne javanica. Lettuce plants infected either with S. sclerotiorum or M. javanica, were sprayed with the synthesized NPs. The photosynthetic quantum yield, net photosynthesis and chlorophyll content index of treated plants were also measured in order to investigate the photocatalytic activity of the NPs. The Cu-based metal NPs and bimetallic CuZn@ZnO NPs were identified as the most effective control agents against S. sclerotiorum and M. javanica and were constituted effective tools to prevent fungal and nematicide infections in agricultural field after further investigation.

The endosymbiotic bacteria that live within the body of insects are involved in many aspects of the host physiology, including reproduction and defence. Thus, the exploitation of these microorganisms may have practical applications for the management of vector-borne diseases. In the Mediterranean area, Philaenus spumarius was identified as the main vector of Xylella fastidiosa. This xylem-restricted bacterium is responsible for several diseases in a variety of agricultural crops of high importance, for which there aren´t any effective control method. Thus, in this work, we evaluated different culture media for the isolation and growth of bacteria living within P. spumarius adults, for their potential exploitation in the management X. fastidiosa. Specifically, was compared the effect of minimal (Luria Bertani - LB) and complex (Modified Melin-Norkrans - MMN) media, with and without fetal bovine serum or gelling agents, on the number and diversity of bacteria. The collection of isolates obtained was further genetically characterized by BOX-PCR and sequencing of the 16S ribosomal RNA (rRNA) gene. Results showed no significant differences in the abundance and diversity of bacteria among the two media tested (LB and MMN). The addition of fetal bovine serum to the media lead to a slight increase in bacterial abundance, in particular in MMN medium. While the liquid media lead to a significant increase in abundance, the solid media facilitated growth of more diverse bacterial taxa. Comparison between BOX-PCR and 16S rRNA gene sequencing for the analysis of 57 bacterial isolates, revealed a greater discriminatory power of the former, allowing the differentiation of the bacteria even at the intra-species level. Clustering of the isolates using BOX-PCR fingerprinting was different from that obtained from the 16S rRNA gene phylogenetic tree. 16S rRNA gene sequencing method proved to be more suitable in phylogenetic evaluations, generally grouping isolates belonging to the same genus.

Acknowledgement: This work has received funding from the European Union’s Horizon 2020 research and innovation programme under Grant Agreement N. 727987 “Xylella fastidiosa Active Containment Through a multidisciplinary-Oriented Research Strategy, XF-ACTORS”.

Seeds have large economic importance all over the world. They are an essential source of minerals, proteins, starch, and oil reserves in the early stages of plant development and growth. A high abundance of such molecules makes seeds of cereals and legumes a major food source for the majority of human world population. However, to gain optimal yield of important crops and to avoid pests, many farmers use pesticides and agrochemicals before, during, or/and after harvesting of crops. Wide and common use of such chemicals can cause pest resistance and harmful effects on soil and the surrounding environment, which represents a global threat to the environment.

The non-thermal or “cold” plasma technology is becoming more and more popular in the field of agriculture. It has been successfully used by scientists for the treatment of various types of seeds under specific conditions. Plasma treatment has, in some cases, triggered specific responses in plant seed growth and development, which could be used to agricultural advantage. Many researchers have reported changes in hydrophilic properties of seed surface and increased water uptake. Moreover, plasma-treated seeds showed improved growth, increased yield and triggered possible plant resistance to abiotic stress such as drought and salinity.

The objective of our experiment is to identify surface changes after cold plasma treatment, and the influence of plasma treatment on seed development and early growth. Different direct and indirect plasma treatments were applied on seeds of two winter wheat varieties. We examined and detected changes in the chemical composition of seed coat and changes in hydrophilic properties of seed surface. Plasma treatment also affected the dynamics of water uptake of seeds, germination rate and the root number of plants.

Mediterranean ecosystems are usually considered resilient to arid conditions, because of their capability to cope with and recover after severe stress events. However, in recent years, extensive tree dieback related to drought events have occurred in different Mediterranean forests. The aim of our research is to investigate the causes of widespread mortality of Quercus ilex observed in Tuscany. Physiological traits were measured through different seasons in an experimental site established in the Maremma Natural Reserve, characterized by areas with high mortality rates of Q. Ilex. To investigate specific physiological and biochemical mechanisms underlying Q. ilex dieback, we have also conducted a pot experiment on three-years old seedlings subjected to progressive water stress followed by rewatering, whereas control plants were maintained in well-watered conditions. In both experiments, the following measurements were carried out: water relations, gas exchanges, chlorophyll fluorescence, carbohydrates, BVOCs, epidermal content of flavonols and chlorophyll. In addition, on shoots collected from plants of the pot experiment we performed target expression analyses focusing on genes involved in drought responses. Results of both studies led us to hypothesize that Q. ilex dieback observed in the Maremma Natural Reserve may be attributed to hydraulic failure. Although holm oak is considered an isohydric species subjected to carbon starvation caused by fast stomatal closure in response to water deficit, xylem embolism may occur under recurrent droughts compromising its ability to recover from severe stresses. Furthermore, both qualitative and quantitative changes in BVOC emissions were found under severe water stress. Considering the intrinsic high emission rates of monoterpenes of this species, variations in the production of these compounds may have implications for the atmospheric biochemistry in Mediterranean areas. In conclusion, our results contribute to elucidate possible mechanisms underpinning recent holm oak forest mortality and provide guidance for understanding Mediterranean forest diebacks under climate changing conditions.

Plants are affected by various biotic and abiotic stresses due to climate change. Tomato and carrots are important crops that are attacked by various pathogens. Fourteen plant growth promoting actinomycetes bacteria (PGPB) of the genus Streptomyces sp. and Nocardiopsis sp. were selected for the biocontrol of several common fungal and bacterial pathogen strains. Antifungal activity was assessed against Fusarium oxysporum f. sp. radicis-lycopersici (FORL) and Rhizoctonia solani (RHS). Antibacterial activity was evaluated against Pseudomonas syringae, Pseudomonas corrugata, Pseudomonas syringae pv. actinidiae, Pectobacterium carotovorum subsp. carotovorum, In vitro antifungal and antibacterial antagonistic activities were evaluated by dual culture method. Fungal-bacterial interaction zones were also analysed by scanning electron microscopy (SEM). From strains with good biocontrol potential, cell-free culture filtrates (CF) were produced and investigated for their in vitro antifungal and antibacterial activity. The most effective strains were also combined in consortium and utilized for the seed treatment for in planta pre-emergence biocontrol assays on both S. lycopersicum and D. carota. For each pathogenic strain, four experimental conditions were compared: CNT (without PGPB/infection), PGPB (with PGPB/no infection), PGPB+INF (with PGPB/infection), INF (with infection/no PGPB). The PGPB strains H12 (Streptomyces albidoflavus) and H14 (Nocardiopsis aegyptica) showed good in vitro antifungal (inhibition > 50%) and antibacterial (inhibition > 10 mm) control. The SEM micrographs showed deterioration of fungal filaments and modification of hyphal structures. The CFs of H12 and H14 were also able to inhibit FORL and RHS in vitro growth (minimum inhibitory concentration of 0.2-0.8%). In planta biocontrol assessments showed that the consortium was effective in reducing the infection effects of both fungal and bacterial pathogens. Consortium allowed normal plant development compared to the control. These results confirm the usefulness of actinomycetes strains as a bio-control agent and can therefore be an alternative to chemicals used in agriculture.

Quinoa is an Andean crop which has gained worldwide attention in the last few decades. This is in part due to the high nutritional value of its seeds (that present high protein content, a balanced amino acid composition and no gluten), and because of its remarkable capacity to grow and adapt to a wide range of agroecological conditions. Despite the importance of developing nutritious varieties to contribute to food security, little efforts have been made trying to identify the molecular pathways responsible for changes in the nutritional properties of the seeds under changing environmental conditions. In this study we aim to evaluate the effect that the adaptation to different environmental conditions has on the nutritional profile of quinoa seeds. For this purpose, we analyzed different physiological and nutritional seed´s traits in six different quinoa varieties grown in the field during three consecutive years (2017, 2018 and 2019). We found that there were differences between cultivars in most of the nutritional parameters analyzed and that the annuity was a determinant factor in every parameter tested, being 2018 the year with lower yields, germinative rates and antioxidant capacity but with higher seed weights and protein contents.

The reaction of leaf growth to drought stress is controlled by various hormones, among which ABA is one of the most important. The aim of this study was to examine the effects of ABA deficiency on tomato leaf response under severe drought stress. Therefore, ABA-mutant (flacca) and wild type (Ailsa Craig) were selected for research and in the stage of 2^nd flower truss anthesis plants were exposed to the severe water deficit. The effects of severe drought on wild-type leaves and flacca mutant showed that, as a result of reduced ABA concentrations, flacca plants were exposed to a higher degree of stress than wild-type leaves, which had a negative impact on the examined physiological and biochemical parameters. Severe drought caused stomatal closure, decreased water potential, specific leaf area, and chlorophyll concentrations in the leaves in both genotypes, but this was more pronounced in the mutant. Wild-type plants have accumulated more vitamins C and ABA and have a higher total antioxidant capacity in the leaves in dry conditions than flacca mutants, which contribute to their better adaptive response to stress. Based on this, it can be assumed that the ABA mutation has led to a decrease in the capacity for oxidative stress products caused by severe drought stress. Analysis of ABA content and leaf water regime parameters showed that stomatal reactions and leaf growth of plants exposed to severe drought stress are the result of hydraulic signals in flacca plants, while in the wild type they are the result of both hydraulic and chemical signals.

Nerium oleander is a plant that has historically been known as a poisonous plant in the world. In several studies, all parts of the oleander are toxic and used to control pests. However, studies on the effects of oleander leave against Rattus argentiventer as a major agricultural rodent pest are limited. This research aimed to probe the potency of oleander leaves that extracted in methanol as rice-field rat repellent by T-test analysis using three replications on mature female and male rice-field rats. The experiments involve a choice test (T-maze arena) and no-choice test (metabolic cage) from February until May 2019. The result of the experiment showed that rice-field rats on the T-Maze avoided consuming food and beverage that close to the methanol extract of oleander leaves treatment. Therefore, the treatment in metabolic cage caused metabolic disorder of rice-field rats, which was indicated by the decrease of the average consumption of food by 2.27 g and excretion of feces by 0.67 g, and also the increase of average consumption of beverage by 4.53 ml, excretion of urine by 1.25 ml. Besides, the treatment also caused daily activity patterns disorder of rice-field rats, which was significantly indicated by the increase of the average percentage of time for resting activities by 2.16 % and the decrease of time for locomotion and nesting activities (by 0.92 % and 1.25 % respectively). In conclusion, oleander leaves have the potential to provide a repellent effect on rice-field rats.