Fusarium Spores Research Articles

Enhanced Quasi-Meshing Hotspot Effect Integrated Embedded Attention Residual Network for Culture-Free SERS Accurate Determination of Fusarium Spores

Enhanced Quasi-Meshing Hotspot Effect Integrated Embedded Attention Residual Network for Culture-Free SERS Accurate Determination of Fusarium Spores

In Vitro evaluation of some fungicidal bioactive chemicals against fusarium spore germination and survival

The genus Fusarium are the most important pathogens associated with different plants including crop plants, fruits, vegetables, etc. causing of constrained production and productivity crops. Bioactive compounds are environmentally friendly and amenable. This study aimed to evaluate the effectiveness of some bio-active compounds derived from Bacillus strain for the in vitro control of Fusarium mold. Seven (7) isolates of the Fusarium complex were isolated from various stored fruits, vegetables and food grains using Potato Dextrose Agar (PDA) media supplemented with antibacterial agent. The growth and survival of the respective spores were challenged with supernatants of overnight-grown culture of Bacillus subtilis TC17 for 20 minutes. The supernatant prevented the germination of spores of some fungi strains in the order; F. solani, F. oxysporum, F. equiseti, F. acuminatum, F. proliferatum, F. moniliforme and F. tricinctum against control. Therefore, this research showed that the bio-active agent can be used to control the pervasive plant pathogenic fungal species with outstanding result and therefore should be developed further for registration for commercial applications.

Behavior of Some Maize Hybrids to the Attack of the European Corn Borer (Ostrinia nubilalis Hbn.) and Fusarium Ear Rot (Fusarium sp.)

European corn borer (Ostrinia nubilalis Hbn.) is the most important pest of maize, for the conditions on Romania. Through injuries produced, both on the stem and ears, it favors the penetration of the spores of Fusarium sp. in the plant. In this paper, some results were presented regarding the reaction of the new maize creations and some perspective hybrids from Agriculture Research and Development Station Turda (ARDS Turda), to the attack of the European corn borer (Ostrinia nubilalis Hbn.) larva and the fusarium ear rot (Fusarium sp.), in the period 2020-2022. The climatic conditions during the summer period, recorded at ARDS Turda, were more favorable to the attack in 2021 and 2022 compared to 2020 for the European corn borer, respectively, more favorable to the attack in 2022 compared to 2021 for the fusarium ear rot. Turda 380 and Turda 2020 hybrids showed a tolerance to the attack of European corn borer larva and the lowest values of fusarium ear rot attack. Turda 332, HST A483-11 and HST A483-39 hybrids were more sensitive both to the attack of Ostrinia nubilalis and Fusarium sp.

Segmentation of wheat scab fungus spores based on CRF_ResUNet++

Accurate segmentation of tiny spore pictures is a significant technique in computer-aided evaluation of wheat scab. A CRF_ResUNet++ spore segmentation model using UNet++ as the fundamental framework is proposed to address the issues of uneven brightness, low spore-background contrast, and spore adhesion in microscopically collected Fusarium spore images. ResNet and fully connected conditional random fields (CRF) are combined in this model to address these issues. First, a residual block ResNet is introduced into UNet++ to enhance the propagation of features and extract more spore detail information. Next, the spore image is initially segmented using UNet++ with an encoder-decoder structure. Finally, postprocessing is carried out using a fully connected conditional random field model to obtain more precise edges and complete spore regions. The laboratory collection dataset test results revealed that the F1-score and MIoU reached 0.943 and 0.925, respectively, with an average detection Precision improvement of 3.2 % over the original UNet++ model. In comparison to existing models, the suggested model can segment spore pictures in challenging circumstances, such as when they contain independent and inter-adherent spores, with excellent computer vision processing capabilities effects and objective evaluation metric segmentation effects. In conclusion, the method in this study can reliably detect and segment adherent wheat scab spores in complex backgrounds, which offers critical technical support for automatic detection of adherent wheat scab spores and early spore concentration prediction in complex environments in the field.

Antifungal activity of Terminalia chebula extract against wilt fungi Fusariumoxysporum an important plant pathogen

Terminalia chebula, a deciduous plant, endogenous to India has medicinal value. Its fruits are known for its cure to many ailments in human beings. This study is to test the Biological activity of these compounds tested against plant pathogenic fungai Fusarium oxysporum which cause wilt in economically important crops. Wilt is a devastating disease whichdestroys the infected plant and cause economic loss to farmers. Panama disease in bananas is a type of wilt disease which is very prevalent in India. This fungai has broad host range from tomato, cotton etc. Outbreak reported in many parts of India. Standard culture of Fusarium oxysporum ITCC -6246, Fusarium oxysporum f. sp. ciceri ITCC 3636 and Fusarium oxysporum f. sp. Lycopersici MTCC 10270 were used to detect the potential chemical compound in dried fruitby macro-dilution.Each organic solvent (Water, Ethanol, Chloroform, Benzene) has different extraction capacity based on the polarity of chemical compound in plants. These chemical compounds extensively studied for their antioxidant property and preliminary screening of chemical compound constituents in all extract. Mycelium growth inhibition tested on solid medium and inhibition measured in mm diameter. Spores of Fusarium sp. present in soil for many months in dormant form. Under suitable climatic conditions this will germinate and cause infection in plants. Rate of spore germination inhibition in liquid medium measured and calculated for every solvent extract. Rate of inhibition was calculated and analysed statistically by t test. The efficient solvent extract determined for bulk extraction of biologically active compound from seeds.

Antifungal activity of Terminalia chebula extract against wilt fungi Fusarium oxysporum an important plant pathogen

Terminalia chebula, a deciduous plant, endogenous to India has medicinal value. Its fruits are known for its cure to many ailments in human beings. This study is to test the biological activity of these compounds tested against plant pathogenic fungi Fusarium oxysporum which cause wilt in economically important crops. Wilt is a devastating disease which destroys the infected plant and cause economic loss to farmers. Panama disease in bananas is a type of wilt disease which is very prevalent in India. This fungi has broad host range from tomato, cotton etc. Outbreak reported in many parts of India. Standard culture of Fusarium oxysporum ITCC -6246, Fusarium oxysporum f. sp. ciceri ITCC 3636 and Fusarium oxysporum f. sp. lycopersici MTCC 10270 were used to detect the potential chemical compound in dried fruit by macro-dilution. Each organic solvent (Water, Ethanol, Chloroform, Benzene) has different extraction capacity based on the polarity of chemical compound in plants. These chemical compounds extensively studied for their antioxidant property and preliminary screening of chemical compound constituents in all extract. Mycelium growth inhibition tested on solid medium and zone of inhibition measured in mm diameter. Spores of Fusarium sp. present in soil for many months in dormant form. Under suitable climatic conditions this will germinate and cause infection in plants. Rate of spore germination inhibition in liquid medium measured and calculated for every solvent extract. Rate of inhibition was calculated and analysed statistically by t test. The efficient solvent extract determined for bulk extraction of biologically active compound from seeds.

A microbial bioherbicide for Striga hermonthica control: production, development, and effectiveness of a seed coating agent.

Witchweed (Striga hermonthica), also called striga, is a parasitic weed that causes high yield losses in maize on more than 200 000 ha in Kenya alone. A new commercial, biological herbicide developed in Kenya is able to control striga effectively. The product was approved for use by the Pest Control Products Board in Kenya in September, 2021. It is self-produced in villages using a secondary inoculum provided by a commercial company. The formulated product has some disadvantages, which are a complicated production process, a very short shelf life and high application rate. Additionally, the product has to be applied manually and therefore can only be used in manual production, leaving out the opportunity for farmers using mechanization. For this reason, efforts have been made to formulate the active ingredient Fusarium oxysporum f. sp. strigae strain DSM 33471, as a powder and to use it as a seed coating agent. This article deals with the production of the Fusarium spore powder, its properties, its application to the seed, and its herbicidal effect demonstrated in the first two field trials. The F. oxysporum strain was originally isolated from a wilting striga plant in Kenya. The strain was virulence enhanced to over produce the amino acids leucine, methionine and tyrosine. These amino acids are responsible for a second mode of action apart from the wilting causing effect of the fungus on striga. Whereas leucine and tyrosine have a herbicidal effect, ethylene from methionine triggers the germination of striga seeds in the soil. Additionally, the strain has been improved to be resistant to the fungicide captan, which is commonly used to treat maize seed in Kenya. Seed coating tests conducted on 25 striga-infested small holder farms spread out in six counties of western Kenya reported yield increases of up to 88%. A second trial carried out by the Kenyan Agricultural and Livestock Research Organization showed a 93% reduction of emerged striga plants. © 2023 Society of Chemical Industry.

Lactic Acid Bacteria as Potential Biocontrol Agents for Fusarium Head Blight Disease of Spring Barley.

Fusarium head blight (FHB) is a devastating disease encountered by spring-grown barley. Traditionally, synthetic chemicals have been used to control this disease on small grain cereals. A move toward biological control agents as part of sustainable agriculture is pertinent due to the evolutionary mechanisms employed by fungal diseases to circumvent current protection strategies. This study evaluated the effect of six lactic acid bacteria isolates on the development of FHB under in vitro and glasshouse conditions. The relative expression of Fusarium marker genes and transcription factors under Fusarium infection was examined. Dual-culture assays observed inhibition zones of up to 10 and 17% of total plate area for L. amylovorus FST 2.11 and L. brevis R2Δ, respectively. Detached leaf assays validated the antifungal activity and showed the potential of all test isolates to significantly inhibit sporulation of Fusarium culmorum and Fusarium graminearum strains. Spray inoculation of lactic acid bacteria to barley spikelets prior to Fusarium spore application significantly reduced disease severity for five candidates (P < 0.05) under glasshouse conditions. Mycotoxin analysis revealed the ability of L. amylovorus DSM20552 to significantly reduce deoxynivalenol content in spikelets (P < 0.05). A preliminary gene expression study showed the positive influence of lactic acid bacteria on the expression of important defense-related marker genes and transcription factors upon FHB. These results indicate the potential of lactic acid bacteria to be included as part of an integrated pest management strategy for the management of FHB disease. This strategy will reduce FHB severity and deoxynivalenol (DON) contamination of spring barley, leading to high acceptance in the grain market.

Blowin’ in the Wind: Wind Dispersal Ability of Phytopathogenic Fusarium in a Wind Tunnel Experiment

Dispersal processes play an essential role in cereal diseases caused by phytopathogenic Fusarium. However, most empirical studies of Fusarium spore dispersal have focused on vertical transport by rain splash, while wind dispersal has been mostly neglected. Our objective was to determine the ability of Fusarium conidiospores to disperse via wind under controlled conditions in a wind tunnel study. Ten Fusarium species with diverse spore varieties were studied by placing them in the wind stream at wind velocities of 5 and 8 m s−1 and collecting them after 6 m and a period of 1 h using a newly developed air sampling box. Although spore concentrations were high in the releasing Petri Dishes, the tested isolates were recaptured in only 18 of 78 runs. F. equiseti and F. cerealis were the most frequently recovered species. Changing abiotic conditions, wind speed, and spore shapes had no significant effect on Fusarium spore recapture rates. Another experiment showed that conidiospores were rarely released from the grown mycelium. Therefore, the importance of wind alone as a dispersal medium for Fusarium conidiospores may have been overestimated so far. Further studies should investigate the importance of carrier media or mobile linkers combined with the wind dispersal of spores.

Bacteria Isolated from the Aeration Chamber of Wastewater Treatment Plants Used in the Biocontrol and Promotion of Wheat Growth

Background: Antagonisms against Fusarium spp. and multi-traits to protect and improve fertilization of wheat by bacterial strains from activated sludge were assessed. Methods: Isolated strains obtained were identified by 16S rRNA gene sequencing and the MALDI-TOF method, and their enzymatic profile was investigated. Treated plant growth-promoting bacteria (PGPB) wheat kernels were grown in pots with soil contaminated with Fusarium conidia. Activated sludge is a collection of microorganisms exposed to strong environmental pressure (chemicals) and antagonistic properties. Results: The isolated bacterial strains were similar to: Ps-1 (Serratia liquefaciens), Ps-15 (Serratia sp.) and Ps-9 (Pseudomonas helleri). The dual culture assay showed the highest antagonism of Ps-9 vs. Fusarium spp. The tested bacteria showed activity in the production of chitinase, a variety of proteases, enzymes that degrade various sugars, and esterase, which creates a complex that allows for a variety of strategies to control phytopathogens. The Ps-9 strain was able to solubilize phosphate. The Ps-9 and Ps-15 strains showed good ammonification ability. A marked improvement was observed in test variants in pots inoculated with Fusarium spores after the use of Ps-9. The Ps-9 strain reduced the disease index to traces of symptoms of both species of Fusarium and increased the grain weight. Conclusions: The Ps-9 strain was proven to have high potential for application in the biocontrol and promotion of wheat growth.

Summer storms and their effects on the spectrum and quantity of airborne bioparticles in Bratislava, Central Europe.

A thunderstorm is a risk factor for severe respiratory allergy or asthma attacks in patients suffering from pollen/spore allergy. This study aimed to investigate the changes in the spectrum and quantity of pollen and fungal spores in the air of Bratislava during summer storms as well as the impact of selected environmental parameters on these changes. Pollen/spore samples were collected using a Burkard volumetric aerospore trap during summer 2016. To identify those types of pollen/spores that may harm human health during the storm episodes, we analysed how the concentration of individual bioparticles in the air changed during pre-storm/storm/post-storm periods. The effect of environmental variables on the concentration of selected pollen/spore types was evaluated through Spearman's correlation analysis. The results of our study suggest that thunderstorm-related respiratory allergy symptoms in the study area may be caused by (1) spores of Myxomycetes, the airborne concentration of which increases due to an increase in wind speed during the pre-storm period; (2) ruptured pollen and Diatripaceae spores, the concentration of which increases due to increase in precipitation and relative air humidity, respectively, during the storm period; and (3) spores of Fusarium and Leptosphaeria, the concentration of which increases due to increase in precipitation and air temperature, respectively, during the post-storm period.

Fungi decontamination by gaseous ozone of fresh, dried and salted mackerel (Acanthocybium solandri)

The aim of this study was to investigate the antifungal effect of ozone gas (O3) (green decontamination agent) on mackerel fish (Acanthocybium solandri) in different types of preservation (fresh, dry and salted). Samples humidity [mc / aw] parameters prior gas treatment, were of 80.7%/0.98, 55.55%/0.74 and 49.5%/0.70, respectively. Fish were contaminated with fungi genera that are able to grow on high (Fusarium) and low (Aspergillus / Penicilliun) moisture content substrates, then gas treated at 50 μmol O3 /mol, exposed during 10, 20 and 30 min, and incubated (25ºC, 7 days) to evaluate fungal inactivation. The O3 treated samples, when O3 exposed during the longest time (30 min/Day 7th) had the fungal growth totally inhibited (100%), while the others presented only reduced growth effect, i.e; 40 and 70 % for 10 and 20 min, respectively. Fusarium spores were not able to grow in any of the protein based sample studied (both, Control &amp; Treated Group). On the other hand, Aspergillus and Penicilliun although grew on Control and some treated ones, their growth was inhibited by O3 depending on exposure time. That gas showed (under the conditions applied) to be fungi control effective for mackerel different forms of conservation.

The Behaviour of Some Winter Wheat Varieties, Created at ARDS Turda Against Fusarium sp. Attack, during 2015-2018

Fusarium head blight (FHB) is a fungal disease of small grain cereals caused by pathogen fungi Fusarium sp. and has become a serious danger to the worldwide grain industry. Under favorable weather conditions (moist, warm conditions during flowering), the Fusarium spores are spread by wind to cereal spikelet, and then, infection expands within the whole ears. Wheat production can be reduced by up to 50-60%, and includes losses caused by flower abortion, elimination of damaged grains during threshing, decrease in grain size, and reduction in grain weight. In this paper we studied the behavior of some wheat varieties at the Fusarium sp., attack, under different infection conditions, between 2015-2018. The climatic conditions had a decisive role in the appearance and development of the disease, the percentage of infected ears and grains, in 2015 and 2016 recorded the highest values. Applying the vegetation treatments, at the optimum time, will lead to the reduction of the percentage of infected ears and kernels, even if there is a high pressure of infection. The yields obtained from the wheat varieties were influenced by the climatic conditions, the infection mode and the cultivated genotype. The lowest yields were obtained in 2017, a problematic year for the winter wheat crop; at the pressure of infection, without treatments, we obtained the lowest yields.

An Air Sampler With Particle Filter Using Innovative Quad-Inlet Cyclone Separator and High Voltage Trap

The air sampler collects all the floating particles in the air, and the samples can be analyzed by a nondispersive thermopile device. These particles are different in size and it is necessary to retain only the size range of the interesting objects in the sampler. With the interest of sampling the Fusarium spores, which have particle diameter range of around $10\mu \text{m}$ to $70\mu \text{m}$ , and eliminating particles smaller than $10\mu \text{m}$ and particles larger than $70\mu \text{m}$ , in this paper, a novel method of combining a quad-inlet cyclone separator and a high voltage trap is proposed. At a small size, such cyclone separator is a new design having four inlets to facilitate the cyclone to intake the particles from any direction. The quad-inlet cyclone separator filters away the large size particles (low pass). By applying di-electrophoretic force in the high voltage portion, the trap can eliminate the small size particles (high pass). The combination of these two devices creates a system, which works as a particle bandpass filter. To investigate the features as well as to study the appropriate parameters of the cyclone and the trap, the numerical simulations for the trap work have been performed by COMSOL Multiphysics. In the simulations, wheat, turmeric, and Fusarium spore objects were investigated. From the simulation, the bandpass ranges of the wheat, turmeric and Fusarium samples are [ $19.5\mu \text{m}-75\mu \text{m}$ ], [ $14.5\mu \text{m}-52.5\mu \text{m}$ ] and [ $15.5\mu \text{m}-67\mu \text{m}$ ], respectively. The experimental results have consolidated that the device can reduce significantly and automatically the presence of small size particles, and especially filter well the particles which have a size larger than $70\mu \text{m}$ . In addition, with the homogeneous electric field in the high voltage trap, the sample distribution on the electrodes was fairly smooth which is useful in later quantifying Fusarium spores by the thermopile device. By using a strong vacuum pump, the internal air sample could be cleaned easily, so the device is reusable. The designed particle band pass filter is essential for our Fusarium detection device and it can be widely applied in the other air sampling and analysis applications.

Adaptive-Cognitive Kalman Filter and Neural Network for an Upgraded Nondispersive Thermopile Device to Detect and Analyze Fusarium Spores.

Noises such as thermal noise, background noise or burst noise can reduce the reliability and confidence of measurement devices. In this work, a recursive and adaptive Kalman filter is proposed to detect and process burst noise or outliers and thermal noise, which are popular in electrical and electronic devices. The Kalman filter and neural network are used to preprocess data of three detectors of a nondispersive thermopile device, which is used to detect and quantify Fusarium spores. The detectors are broadband (1 µm to 20 µm), (6.09 ± 0.06 µm) and (9.49 ± 0.44 µm) thermopiles. Additionally, an artificial neural network (NN) is applied to process background noise effects. The adaptive and cognitive Kalman Filter helps to improve the training time of the neural network and the absolute error of the thermopile data. Without applying the Kalman filter for thermopile, it took 12 min 09 s to train the NN and reach the absolute error of 2.7453 × 104 (n. u.). With the Kalman filter, it took 46 s to train the NN to reach the absolute error of 1.4374 × 104 (n. u.) for thermopile. Similarly, to the (9.49 ± 0.44 µm) thermopile, the training improved from 9 min 13 s to 1 min and the absolute error of 2.3999 × 105 (n. u.) to the absolute error of 1.76485 × 105 (n. u.) respectively. The three-thermopile system has proven that it can improve the reliability in detection of Fusarium spores by adding the broadband thermopile. The method developed in this work can be employed for devices that encounter similar noise problems.

A Nondispersive Thermopile Device With an Innovative Method to Detect Fusarium Spores

Early detecting of fusarium spore in the air is highly desired, as it helps to protect crops from the potential of dangerous fungal disease. This paper focuses on developing a method and building a portable, reliable, and affordable device, which can promptly and continuously detect the presence of fusarium spores in the air. Based on the Beer–Lambert law and the distinct infrared absorbance spectrum of substances, a specification logarithm ratio formula for two different wavelengths is developed. This is the main principle of the detection technique and design of the device. In the system, there are two sensitive infrared thermopiles that work on two specific infrared wavelengths, including $\lambda _{\mathbf {1}} = 6.09 \pm 0.06\,\,\mu \text{m}$ and $\lambda _{\mathbf {2}} = 9.49\pm 0.44\,\,\mu \text{m}$ . The thermopiles are used to measure the infrared light intensity emitted by an infrared light source (2–22 $\mu \text{m}$ ) for the fusarium spore detection analysis. The detection is based on the group distinction coefficient. The Beer–Lambert law also assists in the approximate estimation of the quantity of the spores. For testing the detection ability of the system and the method, besides fusarium spore, other substances, such as sunflower pollen, polyphenol, and starch, were also used in the experiments. The experimental results indicate that the fusarium group-distinction coefficient (1.14 ± 0.15) is distinct from the other investigated substances (pollen: 0.13 ± 0.11, turmeric: 0.79 ± 0.07, and starch 0.94 ± 0.07). The results prove that the system and the proposed method can be used to detect and quantify not only for fusarium but also for other spores, molds, and specific pathogens.

A plant biostimulant made from the marine brown algae Ascophyllum nodosum and chitosan reduce Fusarium head blight and mycotoxin contamination in wheat.

Fusarium head blight (FHB) caused by Fusarium graminearum is a disease that results in yield loss and mycotoxin contamination in wheat globally. This study assessed the effect of a plant biostimulant prepared from a brown macroalga Ascophyllum nodosum (Liquid Seaweed Extract; LSE) alone and in combination with chitosan in controlling Fusarium. Wheat seedlings drenched with LSE and chitosan in combination showed reduced severity of F. graminearum infection on leaves as evidenced by a significant reduction in necrotic area and fewer number of conidia produced in the necrotic area. Gene expression studies showed that the combination of LSE and chitosan amplified the response of pathogenesis-related genes (TaPR1.1, TaPR2, TaPR3, TaGlu2) in wheat seedlings infected with Fusarium spores above that observed for the individual treatments. The combination treatments were more effective in enhancing the activity of various defense related enzymes such as peroxidase and polyphenol oxidase. FHB studies on adult plants showed a reduction of bleached spikes in wheat heads treated with the combination of LSE and chitosan. Mycotoxin content appeared to be correlated with FHB severity. Combination treatments of LSE and chitosan reduced the levels of mycotoxins deoxynivalenol and sambucinol in wheat grains. Systemic disease resistance appears to be induced by LSE and chitosan in response to F. graminearum in wheat by inducing defense genes and enzymes.

Fungal species associated with fruit and vegetables transported to the J.G. Mendel station and the influence of UV-C treatment on their fungal community

The aim of this study was to investigate the fungal community associated with fruits and vegetables transported into the Antarctic region and observe qualitative changes of their surface mycobiota after UV-C treatment. This measure is used to prevent the post-harvest diseases of stored fruits and vegetables and reduce the risk of introducing non-native species to the Antarctic environment. In total, 82 strains of filamentous fungi were isolated from the surfaces of 64 pieces of fresh fruits and vegetables before and after their UV-C treatment. They were assigned to the genera Penicillium, Fusarium, Mucor, Cladosporium, and Acremonium. After the UV-C treatment of the examined fruits and vegetables, spores of the genera Fusarium, Cladosporium and Acremonium were not detected, while spores of the genera Penicillium and Mucor were more resistant and stayed viable after the treatment. Penicillium strains prevailed in the examined samples. Their introduction to the Antarctic environment could represent a potential risk for endemic autochthonous organisms.

Influence of Fusarium avenaceum infections on barley malt: Monitoring changes in the albumin fraction of barley during the malting process

Fusarium spp. are ubiquitous field pathogens, which are known to affect quality characteristics of cereals. Infections with Fusarium pathogens in brewing cereals are problematic and augur for a poor malt quality. The negative effects of Fusarium infections are various. Besides causing agronomic losses, kernel discoloration, and the production of several mycotoxins, Fusarium spp. are known to enhance the proteolytic activity of infected barley malt. Enhanced proteolysis can be observed in higher values in free amino nitrogen (FAN) as well as in soluble nitrogen. Previous studies showed that, in recent crop years, the predominant Fusarium spp. detected in European malt was F. avenaceum. This study focuses on the changes in the albumin fraction during the malting process of barley samples artificially infected with F. avenaceum in comparison to uninfected control samples. The barley samples were grown under controlled conditions in a greenhouse, and two different sample types were studied: One was not infected with Fusarium spores whereas the other sample was inoculated during anthesis with a spore suspension of F. avenaceum. Malting trials were carried out in a micromalting facility under defined conditions. To monitor the changes in protein profiles due to Fusarium infection, samples were analyzed at different stages of the malting process: barley (raw grain), poststeeping, postgermination, and postkilning. To evaluate the changes in the protein composition, different fractionation techniques (Osborne fractionation, isoelectric focusing, and capillary gel electrophoresis) were utilized. The albumins of the Osborne fractionation were further analyzed as they represent the main metabolically active proteins. Protein maps of the different malting steps were plotted with a custom-programmed visualization tool for comparing the infected and uninfected samples at each malting step. The results elucidate the changes in the albumin fraction during the malting process and reveal the influence of Fusarium infection on the albumin composition of barley, barley malt, and the intermediate products of malting.

The Effects of Soil Solarization and Compost on Soil Suppressiveness against Fusarium Oxysporum f. sp. Melonis

ABSTRACTSoil suppressiveness against Fusarium was tested using solarized and non-solarized soils combined with composts of three maturation levels, and a non-amended control. The soils were sampled on three dates: after previous year solarization but before current year solarization (0 weeks), at the end of the solarization period of the current year (4 weeks), and 4 weeks later (recovery time). Melon seedlings were inoculated with Fusarium spores and disease severity was assessed. The study showed a reduction of soil suppressiveness capacity against Fusarium oxysporum f. sp. melonis after 1 year of solarization (0 weeks). Fusarium disease severity in artificially inoculated melon plants, expressed by area under the disease progress curve, was higher in solarized soil than in non-solarized soil. Compost addition lowered the disease severity, both in the solarized and in the non-solarized soils. However, suppression was not obtained at the end of the solarization period, whereas compost beneficial effect was found at this time.