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The evolution of the global scenario, which involves such converging crises as the climate crisis, the COVID-19 pandemic and its aftermath, and the Russia-Ukraine and Israel-Palestine wars, has underscored the fragility of the current food systems and the interdependence of human, animal, plant, and environmental health. Plant health is an important element in all these crises as plants provide food and feed, fix CO2, produce oxygen, and stabilize the soil. As a result of the Covid 19 pandemic, the One Health concept has finally obtained the attention of scientists and funding agencies. However, despite their role in global nutrition, the economy, and in climate crisis, plants are often excluded from the One Health efforts and funding streams. This paper advocates the need for an updated and more holistic view of plant health as public goods within the context of the evolving global challenges and explores opportunities within the Circular Health paradigm.

Women first began to take a stance in science over 50 years ago, and since then, they have produced a great number of publications. However, the first step towards science was a matter of accrediting women as rightful members of the scientific community. During the late nineteenth and early twentieth centuries, women started to enter into graduate programmes, and such a step helped them to make a difference. In many cases and many countries, botanists and mycologists were, in some way, pioneering in the plant pathology discipline. This manuscript considers some of the women who led the way in plant pathology, with a special focus on those who also dealt with the early aspects of plant disease management. Women who were active in different geographical areas are featured, and an attempt has also been made to provide some less well-known stories. Moreover, the importance of women behind the scenes, as is the case for many lab and field technicians, whose lives have not been chronicled, is acknowledged. Finally, some suggestions are given on how to improve the present situation and increase the number of women in science as well as in technical positions, with special emphasis on the positive effect of female mentors and role models.

Curvularia americana and C. tropicalis are described as causes of leaf and crown necroses on Bermuda grass (Cynodon dactylon x Cynodon transvaalensis) in Veneto, Northern Italy. These pathogens were characterized using morphological characters, and a multilocus molecular phylogenetic analysis based on the nuclear ribosomal internal transcribed spacer (ITS) region, the partial glyceraldehyde-3-phosphate dehydrogenase (gapdh) and translation elongation factor-1α (tef1-α) genes. Pathogenicity tests and the fulfilment of Koch’s postulates confirmed C. americana and C. tropicalis as foliar pathogens of Bermuda grass. This is the first report of C. americana and C. tropicalis as pathogens of Bermuda grass, and the first record these two fungi in Europe.

Colletotrichum ocimi causes black spot of basil (Ocimum basilicum) and is a serious threat to basil cultivation as it compromises leaf production. The pathogen also infects seeds, which could become primary sources of inoculum for spread of black spot. A SYBR Green real-time PCR assay was developed to detect Colletotrichum ocimi in basil leaves and seeds, based on the partial β-tubulin (tub2) gene sequence. Two primer sets were designed and tested. The selected primer pairs produced amplicons of 130 bp. The real-time PCR assay was validated for analytical specificity, sensitivity, selectivity, repeatability and reproducibility. The assay was specific for C. ocimi with respect to ten Colletotrichum spp. and to another 12 pathogens of basil plants. Sensitivity was 1 pg µL-1 of genomic fungal DNA and amplification analyses were not influenced by basil genomic DNA. The assay detected and quantified C. ocimi in artificially inoculated basil leaves. This is the first specific primer set for C. ocimi, which allows rapid detection and quantification of the pathogen is a useful tool for diagnostics in plants. Detection in seeds would also be possible, but will require an optimized extraction method. The qPCR detection of C. ocimi in planta can contribute to adoption of effective preventive disease management strategies.

Highbush blueberry is an increasingly important crop due to its economic value and demonstrated health benefits of blueberries. Leaf spots are considered as minor diseases of blueberry plants, but they adversely affect blueberry productivity, causing reduced photosynthetic activity, flower bud formation and berry production. Surveys of blueberry crops were conducted in Piedmont, Northern Italy, during 2019-2020. Fungi isolated from leaf spots of the blueberry cultivar ‘Blue Ribbon’ were identified as Colletotrichum helleniense through a robust multi-locus phylogeny. Eight genomic loci were considered: tub, gapdh, act, cal, his3, chs-1, ApMat and gs. Morphological characters of a representative strain were assessed. Pathogenicity was confirmed on four blueberry cultivars, although with different levels of aggressiveness to the cultivars. This study shows the importance of a polyphasic approach to investigate species of Colletotrichum, and the relevance of molecular tools for the species-level characterization within the ‘Kahawae’ clade. This is the first report of Colletotrichum helleniense causing leaf anthracnose on Vaccinium corymbosum.

Twelve trials, in closed soilless culture under controlled conditions, were carried out to evaluate the efficacy of resistance inducers (based on K-phosphite and K-silicate used alone or in combination), and of experimental biocontrol agents (Trichoderma sp. TW2, a mixture of Pseudomonas FC 7B, FC 8B, and FC 9B, Fusarium solani FUS25, Pseudomonas sp. PB26), and a commercial formulation of Trichoderma gamsii + T. asperellum, against diseases caused by Phytophthora capsici of sweet pepper. The products were applied using three different protocols, and effects on incidence of Phytophthora crown, stem and root rots (% dead plants), disease development (area under the disease progress curve; AUDPC), and plant fresh weights were evaluated. Potassium phosphite, applied directly at standard P2O5:K2O, 1.30 + 1.05 g L-1) and at half standard rates, onto growing media, or via nutrient solution, and before infestation of peat plant growing medium with P. capsici, provided the best disease management in a dose-dependent manner, with an 80% reduction of Phytophthora crown, stem and root rots for the standard dosage and for both types of application. These treatments also reduced proportions of dead plants by 47% from the standard rate and by 62% at the half standard rate, when applied via the nutrient solution or directly to the substrate. K-silicate alone partially reduced the percentage of dead plants, with efficacy of 20–23%. No improvement in disease control was observed when K-silicate was applied in combination with phosphite, while K-silicate alone or combined with K-phosphite reduced disease development, compared to untreated controls. Biocontrol agents (BCAs), applied preventively, reduced Phytophthora crown, stem and root rots, with similar or better results than those from the commercial mixture of Trichoderma asperellum + T. gamsii. Among the tested BCAs, Fusarium solani FUS25 provided the most consistent disease reduction (60–65%) and gave increased plant fresh weights. All the tested BCAs reduced disease development, with a similar trend for different disease pressures. The least AUDPC values, compared to the non-treated controls, were from Fusarium solani FUS25, followed by the tested Pseudomonas strains and Trichoderma sp. TW2. These results indicate the potential for potassium phosphite and biocontrol agents in management of Phytophthora crown, stem and root rots of pepper grown in soilless systems.

Potted plants of Mammillaria painteri (Cactaceae) showing symptoms of stem rot were collected from a nursery in Imperia province, Liguria region, Italy. Isolations from internal rotting tissues allowed gave constantly similar fungal colonies. Morphological characteristics of the isolates identified them as Fusarium oxysporum. Molecular analyses of the elongation factor 1α (EF1α) and RPB2 genes confirmed the identification. Analysis of part of the intergenic spacer (IGS) region of the ribosomal DNA identified the pathogen as F. oxysporum f. sp. opuntiarum. In pathogenicity tests, stems of M. painteri plants were inoculated with representative F. oxysporum f. sp. opuntiarum isolates. Approx. 30 d after the inoculation, yellowing appeared around the inoculated wounds. The inoculated stems then rotted developing symptoms similar to those observed in greenhouse-grown plants. This is the first report of F. oxysporum f. sp. opuntiarum on M. painteri.

Fusarium equiseti, a member of the Fusarium incarnatum-equiseti species complex (FIESC), has recently been reported in Italy as the causal agent of a leaf spot diseases on previously unrecorded plant hosts. This emerging disease has affected leafy vegetable hosts including lettuce, lamb’s lettuce, wild rocket, cultivated rocket, spinach and radish, and has caused symptoms that have not been previously described on those plants. Fifty-two fungal isolates obtained from symptomatic plants and different plant organs were identified according to their morphology as belonging to the FIESC. The present study aimed to characterize these isolates by identifying their FIESC phylogenetic species, and to evaluate their pathogenicity and host ranges. Six phylogenetically different species of FIESC were identified using MLST analyses of four loci (tef1, cmdA, tub2, and IGS). Most of the isolates were found to belong to F. compactum or F. clavum, while the other four FIESC species were represented by only a few isolates. All the fungal isolates were capable of inducing leaf spot diseases as single isolates with fulfilling Koch’s postulates for these fungi. The intraspecies diversity of the FIESC, the seed-originated isolates of four FIESC identified species, and enhanced range of experimental hosts were observed in the FIESC emerging diseases of these vegetable hosts in Italy. Strict seed inspection procedures, and suitable alteration of environmentally friendly fungicides and biological control agents should achieve efficient management of the FIESC leaf spot diseases on vegetable crops, and prevent further spread of these pathogens to new hosts and new geographical areas.

Phytophthora capsici Leonian (PHC) is a filamentous pathogen oomycete that causes root, fruit, foliar and crown rot over a wide host range, including the economically and nutritionally important summer squash (Cucurbita pepo var. cylindrica L.) crop. PHC chemical control strategies are difficult to adopt, due to the limited number of registered chemicals that are permitted and the scalar harvest system. For these reasons, other strategies, such as the use of waste-based composts that can act as suppressive agents against several soilborne pathogens, have been studied intensively. It is well known that compost’s microbiota plays an important role to confer its suppressive ability. In this study, four different composts were analyzed with both 16S rRNA gene and 18S rRNA gene real-time PCR amplification and with 26S gene amplicon-based sequencing; the total abundance of the bacterial and fungal communities was found to be higher compared to literature, thus confirming that the four composts were a good inoculum source for agricultural applications. The core mycobiota was mainly composed of 31 genera; nevertheless, it was possible to observe a clear predominance of the same few taxa in all the composts. The four composts were then tested, at different concentrations (1–10–20% v/v), to establish their ability to confer suppressiveness to the Phytophthora capsici (PHC) – Cucurbita pepo pathosystem in controlled greenhouse pot trials. A total of 12 compost mixtures were considered, and of these, one (Trichoderma-enriched compost at 10% v/v) was able to statistically reduce the disease incidence caused by PHC (by 50% compared to the untreated control). Hence, the microbiota composition of the most effective compost treatment was investigated and compared with untreated and chemical (metalaxyl) controls. Mycobiota sequencing showed genera differences between the three treatments, with relative abundances of several fungal genera that were significantly different among the samples. Moreover, PCA analyses clustered the compost treatment differently from the chemical and the untreated controls. These findings suggest that suppressive activity of a compost is strictly influenced by its microbiota and the applied dosage, but the ability to induce a shaping in the rhizosphere microbial composition is also required.

Viticulture is a cropping system in which treatment against fungal diseases (in particular powdery and downy mildews) can be extremely frequent. Accordingly, a reduction in antimicrobial treatments and the application of environmentally-friendly compounds are becoming increasingly important for a more sustainable viticulture. In addition to their effect against pathogens, the impact of these products on the quality of the grapes is very important for the oenological industries, but unfortunately at present few data are available. We evaluated the effect of the application of biocontrol products and resistance inducers in the vineyard on the mechanical properties, microbial ecology, technological and phenolic maturity of Vitis vinifera “Nebbiolo” grapes at harvest. The yield and vigor of vines were not influenced by the treatments, nor were the production of primary and secondary metabolites. However, the active ingredients influenced the mechanical properties of the skin (hardness and thickness). A significant hardening of the skin was detected when laminarin and chito-oligosaccharides were used, and sulfur induced a thickening of the skin with potential consequences for wine quality. Furthermore, the yeast community present on grape berries was influenced by the treatments. The abundance of Aureobasidium pullulans, the dominant species on the grape berry, changed in response to the compounds used. In addition, Alternaria sp. was reduced in some treatments with a potentially positive effect on the quality and the safety of the grapes. This study provides an overview of the effect of biocontrol products and resistance inducers on microbial ecology and “Nebbiolo” grape quality, contributing to the establishment of more sustainable and effective defense strategies in viticulture.

Effects of anaerobic soil disinfestation (ASD) on Rhizoctonia solani basal rot of lettuce were assessed considering: two soil types; different C-sources; different temperature regimes; two treatment durations; and two lettuce crop cycles, in the presence of a high disease incidence from artificial infestation with the pathogen. C-source, temperature, and incubation period, and their interaction, affected the efficacy of the ASD treatment for the lettuce–R. solani pathosystem, with differences depending on the soil type. Brassica carinata pellets, used as a C-source, reduced incidence of Rhizoctonia basal rot in the first crop cycle by 50 to 69% in a peat soil after 3 weeks of treatment at 21°C, and by 52 to 60% after 3 weeks of treatment at 26 or 31°C, compared to the inoculated and untreated experimental controls without anaerobic conditions. The best disease reduction was provided by B. carinata pellets applied, under anaerobic conditions, to peat soil (79% efficacy) and a sandy loam soil (100% efficacy) kept at 31°C for 6 weeks. Generally, ASD based on B. carinata pellets provided greater disease reduction in the first crop cycle than the second, with the only exception being for results achieved in both soils incubated for 6 weeks at 21, 26 and 31°C. Wild rocket used as a C-source provided the greatest disease reduction (78–83%) on plants grown in peat soil at the first crop cycle after 6 weeks of the ASD treatment at 31°C, while wild rocket provided disease reduction of 29 and 50% when mixed with the sandy-loam soil under the same conditions for 6 weeks. The efficacy of the ASD treatment with compost was improved in the second crop cycle, compared to the first, resulting in the greatest disease reduction (52 and 66% efficacy) reached in the sandy-loam soil incubated for 3 weeks at 21°C, and 63% efficacy in peat soil previously treated for 6 weeks at 26 and 31°C. However, slight reductions in lettuce plant development was generally evident in the first crop cycle, which could be due to differences in efficacy of the tested ASD treatments and to phytotoxicity. The greatest yield from sandy loam soil was obtained for the B. carinata pellets and wild rocket at 26 and 31°C in the second cultivation cycle. Partial efficacy of ASD does not justify the adoption of this method against R. solani on lettuce under intensive crop systems. However, ASD based on Brassicaceae and compost as carbon source applied in a sandy-loam soil may be valuable for reducing R. solani incidence, at lower temperatures than those required for soil solarisation or biosolarisation.

The effect of simulated climate changes by applying different temperatures and CO₂ levels was investigated in the Blumeria graminis f. sp. tritici/wheat pathosystem. Healthy and inoculated plants were exposed in single phytotrons to six CO₂+temperature combinations: (1) 450 ppm CO₂/18–22°C (ambient CO₂ and low temperature), (2) 850 ppm CO₂/18–22°C (elevated CO₂ and low temperature), (3) 450 ppm CO₂/22–26°C (ambient CO₂ and medium temperature), (4) 850 ppm CO₂/22–26°C (elevated CO₂ and medium temperature), (5) 450 ppm CO₂/26–30°C (ambient CO₂ and high temperature), and (6) 850 ppm CO₂/26–30°C (elevated CO₂ and high temperature). Powdery mildew disease index, fungal DNA quantity, plant death incidence, plant expression of pathogenesis-related (PR) genes, plant growth parameters, carbohydrate and chlorophyll content were evaluated. Both CO₂ and temperature, and their interaction significantly influenced powdery mildew development. The most advantageous conditions for the progress of powdery mildew on wheat were low temperature and ambient CO₂. High temperatures inhibited pathogen growth independent of CO₂ conditions, and no typical powdery mildew symptoms were observed. Elevated CO₂ did not stimulate powdery mildew development, but was detrimental for plant vitality. Similar abundance of three PR transcripts was found, and the level of their expression was different between six phytotron conditions. Real time PCR quantification of Bgt was in line with the disease index results, but this technique succeeded to detect the pathogen also in asymptomatic plants. Overall, future global warming scenarios may limit the development of powdery mildew on wheat in Mediterranean area, unless the pathogen will adapt to higher temperatures.

Fusarium fujikuroi, causing bakanae disease, is one of the most important seedborne pathogens of rice, the detection of which is paramount for seed certification and for preventing field infections. Molecular tests—qPCR and loop-mediated isothermal amplification (LAMP)—are replacing the blotter test in seed health procedures, due to higher sensitivity, specificity, fast turnaround results delivery, on-site application and the possibility of quantifying endophytic seed infections. A LAMP test, which had been previously developed with primers designed to target the elongation factor 1-α sequence of F. fujikuroi, was validated according to the international validation standard (EPPO, PM7/98) on thirty-four rice seed lines of different levels of susceptibility to the disease, thus comparing it to the blotter test and with two different DNA extraction procedures. The use of crude extracted DNA provided more sensitive results than the DNA extracted with the commercial kit Omega E.Z.N.A® Plant DNA kit. The results showed that the endophytic infection of F. fujikuroi is essential for the development of the disease in the field and that the minimum amount of the pathogen necessary for the development of the disease corresponds to 4.17 × 104 cells/µL. This study confirms the applicability of the LAMP technique on-site on rice seeds with fast and quantitative detection of the pathogen.

Abstract Background Bakanae disease, caused by seed-borne Fusarium species, mainly F. fujikuroi, is a rice disease whose importance is considerably increasing in several rice growing countries, leading to incremental production losses. Results A germplasm collection of japonica rice was screened for F. fujikuroi resistance, allowing the identification of accessions with high-to-moderate levels of resistance to bakanae. A GWAS approach uncovered two genomic regions highly associated with the observed phenotypic variation for response to bakanae infection on the short arm of chromosome 1 (named as qBK1_628091) and on the long arm of chromosome 4 (named as qBK4_31750955). High levels of phenotypic resistance to bakanae were associated to the cumulated presence of the resistant alleles at the two resistance loci, suggesting that they can provide useful levels of disease protection in resistance breeding. A fine comparison with the genomic positions of qBK1_628091 and qBK4_31750955 with respect to the QTLs for bakanae resistance reported in the literature suggests that the resistant loci here described represent new genomic regions associated to F. fujikuroi resistance. A search for candidate genes with a putative role in bakanae resistance was conducted considering all the annotated genes and F. fujikuroi-related DEGs included in the two genomic regions highlighting several gene functions that could be involved in resistance, thus paving the way to the functional characterization of the resistance loci. Conclusions New effective sources for bakanae resistance were identified on rice chromosomes 1 and 4 and tools for resistance breeding are provided.

A disease is recognized as emerging if it is new, it occurs in a new host, there is an unexpected outbreak, its economic importance increases, if it attracts public opinion and the scientific community regardless of economic importance, or if it appears in an area for the first time (referred to as geographic emergence). This review deals with major driving factors of the emergence of plant diseases caused by soil-borne fungi and oomycetes (here indicated as “fungi”), in Italy during recent years. These factors include: accidental introduction of alien pathogens by human activities; effect of climate change; unusually severe weather events; favourable environmental and ecological conditions; pathogen genetic variation; host shifts and expansion of host ranges; introduction or expansion of the geographic range of a susceptible plant species or variety; limited availability of fungicides or development of fungicide-resistance pathogen strains; changes of cropping systems; and/or increased pathogen in soil as a consequence of intensive monoculture of crops. Although in most cases more than a single driving factor contributes to the emergence of an infectious disease, there are examples where a determinant may prevail over others. The case studies reviewed include pathogens belonging to major genera of soil-inhabiting fungi and oomycetes, including Armillaria, Calonectria, Coniella, Fusarium sensu lato, Ilyonectria, Monosporoascus, Plectosphaerella, Rhizoctonia, Rosellinia, Sclerotinia, Sclerotium, Verticillium, Pythium and Phytophthora. The examples encompass natural and forest ecosystems, economically important agricultural crops including citrus, fruit trees, olive, legumes, vegetables, and ornamentals, as well as exotic or expanding minor crops, such as avocado, goji berry, and pomegranate. Whatever the prevailing driving factor(s) these case studies all show that the large-scale emergence of soil-borne fungal diseases of plants is the consequence of human activities.

Severe outbreaks of Alternaria leaf spot have occurred in Northern Italy on leafy vegetable and ornamental hosts. This disease is mainly controlled by two classes of respiration inhibitor fungicides, QoIs (including azoxystrobin) and SDHIs (including boscalid). Thirty-six Alternaria strains were isolated from five leafy vegetable crops, and subjected to molecular characterization. Multilocus phylogenetic analyses assigned most of the strains (86%) to A. alternata, while the rest were A. arborescens and other Alternaria spp. In vitro sensitivity assays showed that 3% of the strains were of intermediate resistance, and 11% of reduced sensitivity to azoxystrobin, while 8% of the strains were resistant to boscalid. Sequencing of cytochrome b in an intermediately resistant strain of Alternaria revealed the G143A mutation. This strain was also resistant to boscalid. None of the tested Alternaria strains had amino acid mutations associated with boscalid resistance coded by the SdhB and SdhC genes. This is the first report of azoxystrobin resistance in A. alternata in Italy, as well as the first record of resistance of Alternaria spp. found on leafy vegetables. As boscalid resistance was not associated with any frequently reported mutations, further investigations of the additional resistance mechanisms are necessary. These results demonstrate the need for well-organized chemical control of emerging Alternaria diseases, to prevent the increase of resistance to QoI and SDHI fungicide classes, and the possibility of double fungicide resistance in these pathogens.

This study represents the first survey studying the occurrence, genetic diversity, and pathogenicity of Botryosphaeriaceae species associated with symptomatic citrus species in citrus-production areas in five European countries. Based on morphological features and phylogenetic analyses of internal transcribed spacer (ITS) of nuclear ribosomal DNA (nrDNA), translation elongation factor 1-alpha (TEF1) and β-tubulin (TUB2) genes, nine species were identified as belonging to the genera Diplodia, Dothiorella, Lasiodiplodia, and Neofusicoccum. Isolates of Neofusicoccum parvum and Diplodia pseudoseriata were the most frequently detected, while Dothiorella viticola had the widest distribution, occurring in four of the five countries sampled. Representative isolates of the nine Botryosphaeriaceae species used in the pathogenicity tests caused similar symptoms to those observed in nature. Isolates assayed were all re-isolated, thereby fulfilling Koch’s postulates. Isolates of Diplodia pseudoseriata and Diplodia olivarum are recorded for the first time on citrus and all species found in our study, except N. parvum, are reported for the first time on citrus in Europe.

This study was aimed at identifying Alternaria species associated with heart rot disease of pomegranate fruit in southern Italy and characterizing their mycotoxigenic profile. A total of 42 Alternaria isolates were characterized. They were obtained from pomegranate fruits with symptoms of heart rot sampled in Apulia and Sicily and grouped into six distinct morphotypes based on macro- and microscopic features. According to multigene phylogenetic analysis, including internal transcribed spacer (ITS), translation elongation factor 1-α (EF-1α), glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and a SCAR marker (OPA10-2), 38 isolates of morphotypes 1 to 5 were identified as Alternaria alternata, while isolates of morphotype 6, all from Sicily, clustered within the Alternaria arborescens species complex. In particular, isolates of morphotype 1, the most numerous, clustered with the ex-type isolate of A. alternata, proving to belong to A. alternata. No difference in pathogenicity on pomegranate fruits was found between isolates of A. alternata and A. arborescens and among A. alternata isolates of different morphotypes. The toxigenic profile of isolates varied greatly: in vitro, all 42 isolates produced tenuazonic acid and most of them other mycotoxins, including alternariol, alternariol monomethyl ether, altenuene and tentoxin.

The airborne mycobiota has been understudied in comparison with the mycobiota present in other agricultural environments. Traditional, culture-based methods allow the study of a small fraction of the organisms present in the atmosphere, thus missing important information. In this study, the aerial mycobiota in a rice paddy has been examined during the cropping season (from June to September 2016) using qPCRs for two important rice pathogens (Pyricularia oryzae and Bipolaris oryzae) and by using DNA metabarcoding of the fungal ITS region. The metabarcoding results demonstrated a higher alpha diversity (Shannon–Wiener diversity index H′ and total number of observed species) at the beginning of the trial (June), suggesting a higher level of community complexity, compared with the end of the season. The main taxa identified by HTS analysis showed a shift in their relative abundance that drove the cluster separation as a function of time and temperature. The most abundant OTUs corresponded to genera such as Cladosporium, Alternaria, Myrothecium, or Pyricularia. Changes in the mycobiota composition were clearly dependent on the average air temperature with a potential impact on disease development in rice. In parallel, oligotyping analysis was performed to obtain a sub-OTU identification which revealed the presence of several oligotypes of Pyricularia and Bipolaris with relative abundance changing during monitoring.

Aspergillus flavus and A. parasiticus are two species able to produce aflatoxins in foodstuffs, and in particular in hazelnuts, at harvest and during postharvest phase. As not all the strains of these species are aflatoxin producers, it is necessary to develop techniques that can detect aflatoxigenic from not aflatoxigenic strains. Two assays, a LAMP (loop-mediated isothermal amplification) and a real time PCR with TaqMan® probe were designed and validated in terms of specificity, sensitivity, reproducibility, and repeatability. The capability of the strains to produce aflatoxins was measured in vitro and both assays showed to be specific for the aflatoxigenic strains of A. flavus and A. parasiticus. The limit of detection of the LAMP assay was 100–999 picograms of DNA, while the qPCR detected 160 femtograms of DNA in hazelnuts. Both techniques were validated using artificially inoculated hazelnuts and naturally infected hazelnuts. The qPCR was able to detect as few as eight cells of aflatoxigenic Aspergillus in naturally infected hazelnut. The combination of the LAMP assay, which can be performed in less than an hour, as screening method, with the high sensitivity of the qPCR, as confirmation assay, is able to detect aflatoxigenic strains already in field, helping to preserve the food safety of hazelnuts.

Penicillium spp. are emerging as producers of mycotoxins and other toxic metabolites in nuts. A HPLC-MS/MS method was developed to detect 19 metabolites produced by Penicillium spp. on chestnuts, hazelnuts, walnuts and almonds. Two extraction methods were developed, one for chestnuts and one for the other three nuts. The recovery, LOD, LOQ and matrix effect were determined for each analyte and matrix. Correlation coefficients were always >99.99%. In walnuts, a strong signal suppression was observed for most analytes and patulin could not be detected. Six strains: Penicillium bialowiezense, P. brevicompactum, P. crustosum, P. expansum, P. glabrum and P. solitum, isolated from chestnuts, were inoculated on four nuts. Chestnuts favored the production of the largest number of Penicillium toxic metabolites. The method was used for the analysis of 41 commercial samples: 71% showed to be contaminated by Penicillium-toxins. Cyclopenin and cyclopenol were the most frequently detected metabolites, with an incidence of 32% and 68%, respectively. Due to the risk of contamination of nuts with Penicillium-toxins, future studies and legislation should consider a larger number of mycotoxins.

Black spot is a major foliar disease of sweet basil (Ocimum basilicum) present in a typical cultivation area of northern Italy, including the Liguria and southern Piedmont regions, where this aromatic herb is an economically important crop. In this study, 15 Colletotrichum isolates obtained from sweet basil plants with symptoms of black spot sampled in this area were characterized morphologically and by nuclear DNA analysis using internal transcribed spacers (ITS) and intervening 5.8S nrDNA as well as part of the β-tubulin gene (TUB2) regions as barcode markers. Analysis revealed all but one isolate belonged to the recently described species C. ocimi of the C. destructivum species complex. Only one isolate was identified as C. destructivum sensu stricto (s.s.). In pathogenicity tests on sweet basil, both C. ocimi and C. destructivum s.s. isolates incited typical symptoms of black spot, showing that although C. ocimi prevails in this basil production area, it is not the sole causal agent of black spot in northern Italy. While no other hosts of C. ocimi are known worldwide, the close related species C. destructivum has a broad host range, suggesting a speciation process of C. ocimi within this species complex driven by adaptation to the host.

Venturia inaequalis, an agent of apple scab, is the most important pathogen of Malus x domestica. Control measures against this pathogen rely on intensive phytosanitary programs based on predictive models to identify the meteorological conditions conducive to the primary infection. The detection of the pathogen in field, both in naturally infected symptomatic and asymptomatic leaves, is desirable. Loop-mediated isothermal amplification (LAMP) assays are profitable molecular diagnostic tools for the direct detection of pathogens in field. A LAMP assay for V. inaequalis has been designed on the elongation factor 1-alpha sequence. The validation of the LAMP assay was carried out following the international EPPO standard PM 7/98 in terms of specificity, sensitivity, repeatability and reproducibility. Specificity testing was performed using target and non-target species, such as phylogenetically related Venturia species and other pathogens commonly found in apple, resulting in positive amplification only for the target with a time to positive ranging from 20 to 30 min. Sensitivity testing was performed with serial dilutions of DNA of the target and by artificial inoculation of young apple leaves. The reliability of the LAMP assay as an early-detection tool and its user-friendly application make it suitable for the diagnosis of apple scab in the field.

Fungi belonging to the genus Alternaria are common pathogens of fruit and vegetables with some species able to produce secondary metabolites dangerous to human health. Twenty-eight Alternaria isolates from rocket and cabbage were investigated for their mycotoxin production. Five different Alternaria toxins were extracted from synthetic liquid media and from plant material (cabbage, cultivated rocket, cauliflower). A modified Czapek-Dox medium was used for the in vitro assay. Under these conditions, more than 80% of the isolates showed the ability to produce at least one mycotoxin, generally with higher levels for tenuazonic acid. However, the same isolates analyzed in vivo seemed to lose their ability to produce tenuazonic acid. For the other mycotoxins; alternariol, alternariol monomethyl ether, altenuene and tentoxin a good correlation between in vitro and in vivo production was observed. In vitro assay is a useful tool to predict the possible mycotoxin contamination under field and greenhouse conditions.

[This corrects the article DOI: 10.1371/journal.pone.0200569.].

Aspergillus fumigatus, the causal agent of human aspergilloses, is known to be non-pathogenic in plants. It is present as saprophyte in different types of organic matter and develops rapidly during the high-temperature phase of the composting process. Aspergilloses are treated with demethylation inhibitor (DMI) fungicides and resistant isolates have been recently reported. The present study aims to estimate the abundance, genetic diversity and DMI sensitivity of A. fumigatus during the composting process of orange fruits. Composting of orange fruits resulted in a 100-fold increase in A. fumigatus frequency already after 1 week, demonstrating that the degradation of orange fruits favoured the growth of A. fumigatus in compost. Most of A. fumigatus isolates belonged to mating type 2, including those initially isolated from the orange peel, whereas mating type 1 evolved towards the end of the composting process. None of the A. fumigatus isolates expressed simultaneously both mating types. The 52 investigated isolates exhibited moderate SSR polymorphisms by formation of one major (47 isolates) and one minor cluster (5 isolates). The latter included mating type 1 isolates from the last sampling and the DMI-resistant reference strains. Only few isolates showed cyp51A polymorphisms but were sensitive to DMIs as all the other isolates. None of the A. fumigatus isolates owned any of the mutations associated with DMI resistance. This study documents a high reproduction rate of A. fumigatus during the composting process of orange fruits, requesting specific safety precautions in compost handling. Furthermore, azole residue concentrations in orange-based compost were not sufficient to select A. fumigatus resistant genotypes.

Species of Colletotrichum are considered important plant pathogens, saprobes, and endophytes on a wide range of host plants. In Italy, several Colletotrichum species have been reported in glasshouse environments. In this study, we have explored the occurrence, diversity, and pathogenicity of Colletotrichum spp. associated with aromatic and ornamental plants belonging to the Lamiaceae family. Surveys were carried out during the 2011−2018 period in Liguria and Piedmont, Italy. A total of 19 Colletotrichum isolates were collected from symptomatic leaves and seeds of Ocimum basilicum (basil), Origanum vulgare (oregano) and different Salvia spp. A multi-locus phylogeny was established based on the basis of four genomic loci (ITS, GAPDH, ACT and TUB2). The aggressiveness of selected, representative isolates were tested. Colletotrichum isolates were identified as being members of three major species complexes: C. acutatum, C. destructivum, and C. gloeosporioides. Colletotrichum fioriniae, C. bryonicola, and C. fructicola were found in association with leaf lesions on Salvia leucantha, S. nemorosa, and S. greggii, respectively. Colletotrichum nigrum was isolated from twig lesions of S. greggii. Moreover, C. fioriniae and C. ocimi were found to be responsible for causing leaf anthracnose of oregano and basil, respectively. All the tested isolates were pathogenic and reproduced identical symptoms to those observed in commercial glasshouses. The present study improves our understanding of Colletotrichum species associated with several hosts belonging to the Lamiaceae family, which are cultivated extensively throughout Italy for different purpose, and provides information that may be useful for an effective disease management program.

The most common technique used to detect ochratoxin A (OTA) in food matrices is based on extraction, clean-up, and chromatography detection. Different clean-up cartridges, such as immunoaffinity columns (IAC), molecular imprinting polymers (MIP), Mycosep™ 229, Mycospin™, and Oasis® HLB (Hydrophilic Lipophilic balance) as solid phase extraction were tested to optimize the purification for red wine, beer, roasted coffee and chili. Recovery, reproducibility, reproducibility, limit of detection (LOD) and limit of quantification (LOQ) were calculated for each clean-up method. IAC demonstrated to be suitable for OTA analysis in wine and beer with recovery rate >90%, as well as Mycosep™ for wine and chili. On the contrary, MIP columns were the most appropriate to clean up coffee. A total of 120 samples (30 wines, 30 beers, 30 roasted coffee, 30 chili) marketed in Italy were analyzed, by applying the developed clean-up methods. Twenty-seven out of 120 samples analyzed (22.7%: two wines, five beers, eight coffees, and 12 chili) resulted positive to OTA. A higher incidence of OTA was found in chili (40.0%) more than wine (6.6%), beers (16.6%) and coffee (26.6%). Moreover, OTA concentration in chili was the highest detected, reaching 47.8 µg/kg. Furthermore, three samples (2.5%), two wines and one chili, exceeded the European threshold.

Plectosphaerella cucumerina that has recently been described as causing a leaf spot on wild rocket (Diplotaxis tenuifolia) in Italy, but has not yet been recorded on this host in other countries. This fungus has the potential to cause severe economic losses to the salad-producing industry, especially in Italy. This paper describes the development of a real-time PCR assay based on internal transcribed spacer (ITS) sequence, to aid diagnosis of this pathogen in culture and in plant material. The assay showed no cross reaction with closely related Plectosphaerella species or with 18 other commonly found fungi, and was able to detect 10 fg of Pa. cucumerina DNA per reaction. The assay was more specific than previously available molecular methods. A comparison of molecular and isolation methods indicated that the real-time PCR method is suitable for detection of the pathogen on plant material.

The Intergovernmental Panel on Climate Change in its recent fourth assessment report predicts that, because of higher concentrations of greenhouse gases in the atmosphere, until 2100 the global mean temperature would rise between 0.6 and 4°C, in combination with changes in precipitation and an increased frequency of extreme weather events. Despite this trend, the extent and mechanisms through which elevated CO2 affects plant diseases remain uncertain. Increases in CO2 and temperatures are also expected to induce complex effects on plant pathogens. Although re- 10 search on the effects of climate change continues to be limited, new tools are permitting to study the effects of climate variables on infection rates in the case of some pathosystems. The shortage of critical epidemiological data on individual plant diseases needs to be addressed using experimental approaches. A useful tool for such types of studies is represented by phytotrons. Hereby, a new phytotron typology, built with the specific aim of studying the effect of climate change on plant disease, is described. Beginning from a general plant overview, key mechanical and electrical systems are described (i.e. air temperature and relative humidity control, lighting and CO2 control system etc.) as environmental parameters and operation cycle are summarized. In particular both parameters which could be set and monitored and those measured and stored are reported. After a suitable testing period, several operation cycles were performed in order to assess the control system’s stability and to optimize the management of all systems involved and the first experimental trials were carried out. The effect of three different simulated climatic conditions: 450 ppm of CO2 with standard temperature (ranging from 18 to 24°C or 18 to 26°C), elevated CO2 (800 ppm) with standard temperature and elevated CO2 (800 ppm) with elevated temperature (4°C higher than standard) on the development of grape powdery and downy mildew were tested.

A collection of 356 isolates of Aspergillus spp. collected during 2006 and 2007 from grapevines in northern Italy were identified through Internal Transcribed Spacer based Restriction Fragment Length Polymorphism (ITS-RFLP) and tested for ochratoxin A (OTA) production. Restriction endonuclease digestion of the ITS products using the endonucleases HhaI, HinfI and RsaI, distinguished five different RFLPs. From each pattern, three samples were sequenced and the nucleotide sequences showed different species corresponding to Aspergillus niger, A. carbonarius, A. tubingensis, A. japonicus and A. aculeatus. By comparing the sequences of the ITS regions, also the uniseriate species A. japonicus and A. aculeatus could be differentiated by HinfI digestion of the ITS products. Among the aspergilli, A. niger was the major species associated with grapes during 2006 (57.4%), while A. carbonarius was the major species during 2007 (46.6%). All the strains of Aspergillus were tested for their ability to produce OTA on Yeast extract sucrose medium (YES), as it was tested as an optimal substrate for the evaluation of OTA production by black aspergilli. Out of 356 isolates, 63 (17.7%) isolates produced OTA ranging from 0.05 to 3.0 µg mL−1. Most of the ochratoxigenic isolates were A. carbonarius (46) in both years, but also some strains of A. tubingensis (11) and A. japonicus (6) produced lower amounts of OTA.

Chestnut drying is used to prevent postharvest losses and microorganism contamination during storage. Several studies reported the contamination by aflatoxins (AFs) produced by Aspergillus spp. in chestnuts. The effect of drying temperatures (from 30 to 50 °C) was evaluated on the growth of A. flavus and the production of aflatoxins in chestnuts. The influence of the treatment on the proximate composition, the total phenol content and antioxidant activity of chestnuts was considered. Fungal colonization was observed on the nuts dried at 30, 35, and 40 °C; the incidence was lower at 40 °C. The highest concentrations of AFB1 and AFB2 were produced at 40 °C. No aflatoxins were detected at 45 or 50 °C. At 40 °C A. flavus was under suboptimal conditions for growth (aw 0.78), but the fungus was able to synthesize aflatoxins. As the temperatures applied increased, the total phenol content increased, while the antioxidant activity decreased. A drying treatment at 45 °C for seven days (aw 0.64) could be a promising method to effectively control both the growth of aflatoxigenic fungi and the production of aflatoxins. This study provides preliminary data useful to improve the current drying conditions used in chestnut mills, to reduce both fungal growth and aflatoxin production.

The primary production of fresh soft fruits was considered to be a suspected critical point for the contamination of frozen berries that were responsible for the large 2013–2014 Hepatitis A virus (HAV) outbreak in Europe. In this study, an Italian berries’ production area was studied for its agro-technical characteristics, and the fresh fruits were analyzed for the presence of enteric viruses (HAV and Norovirus (NoV) genogroup I and genogroup II (GGI and GGII)), the enumeration of hygienic quality parameters, and the prevalence of bacterial pathogens. A total of 50 producers were sampled, who specialized in the exclusive or shared cultivation of berries. Escherichia coli was detected in two blackberry samples, whereas HAV and Norovirus were not detected. The samples were negative for Salmonella spp., Listeria monocytogenes, and Shiga toxin-producing Escherichia coli (STEC). The farms’ attributes were not associated with positive samples, apart from the presence of E. coli and the aerobic mesophilic bacteria for blackberry that were statistically correlated. In blueberries, the high aerobic mesophilic count could likely be associated with the resistance of the outer layer to handling. However, the two pathogens (Salmonella spp. and STEC) and the targeted viruses (HAV, NoV GGI and GGII) were not detected, highlighting the low risk of foodborne pathogens and viral contamination at the primary production stage of the berry food chain in the area considered in this pilot study.

Integrated Pest Management (or IPM) is a decision-making process that prevents pest activity and infestation by combining several strategies to achieve long-term solutions. Components of an IPM program may include education, proper waste management, structural repair, maintenance, biological and mechanical control techniques, and pesticide application. These tactics should meet economic, public health and environmental goals. In this paper new methods and strategies of pest control in cereal chain are reported.

analysis based on the ITS region confirmed the pathogen as Fusarium oxysporum. In order to identify the forma specialis, thirteen isolates obtained from infected tissues were used for phylogenetic analysis based on four polygalacturonase genes (Pg1, Pg5, Pgx1 and Pgx4) together with the translation elongation factor 1-alpha (EF-1alpha) gene. Sequences generated in this study were aligned with other formae speciales of Fusarium oxysporum from GenBank to construct phylogenetic trees. Eleven isolates of a new forma specialis, Fusarium oxysporum f. sp. crassulae described on Crassula ovata, were added to the analysis based on Pg5 and Pgx1 genes. The results obtained for each genomic region showed that the isolates derived from E. agavoides are in a unique group well separated from other formae speciales already described. The first report of F. oxysporum on E. agavoides together with the results obtained in this study suggest a new forma specialis, here named F. oxysporum f. sp. echeveriae.

Symptoms of a new vascular wilt were observed on several plants of Papaver nudicaule cultivated at the Regional Institute for Floriculture in Sanremo and in a nursery near Ventimiglia, Liguria region, Northern Italy. Morphology and ITS sequence analysis characterize the pathogen as Fusarium oxysporum. To identify the forma specialis, eight isolates obtained from infected tissues were used for a phylogenetic analysis based on translation elongation factor 1-α (EF-1α) gene and four polygalacturonase genes (Pg1, Pg5, Pgx1 and Pgx4). After amplification by PCR, the gene sequences were aligned with corresponding sequences from other formae speciales of Fusarium oxysporum obtained from GenBank databases in order to build phylogenetic trees. Results obtained for each genomic region showed that the isolates derived from P. nudicaule form a unique group well separated from other formae speciales. To our knowledge, this is the first report of F. oxysporum on P. nudicaule and together with the phylogenetic analysis and positive pathogenicity tests permits us to introduce a new forma specialis named F. oxysporum f. sp. papaveris.

The efficacy of thyme and savory essential oils were investigated against Botrytis cinerea on apple fruit. Apples treated with thyme and savory essential oils showed significantly lower gray mold severity and incidence. Thyme essential oil at 1% concentration showed the highest efficacy, with lower disease incidence and smaller lesion diameter. The expression of specific pathogenesis-related (PR) genes PR-8 and PR-5 was characterized in apple tissues in response to thyme oil application and B. cinerea inoculation. After 6 h of pathogen inoculation, thyme essential oil induced a 2.5-fold increase of PR-8 gene expression compared to inoculated fruits. After 24 h of inoculation, PR-8 was highly induced (7-fold) in both thyme oil-treated and untreated apples inoculated with B. cinerea. After 48 h of inoculation, PR-8 expression in thyme-treated and inoculated apples was 4- and 6-fold higher than in inoculated and water-treated apples. Neither thyme oil application nor B. cinerea inoculation markedly affected PR-5 expression. These results suggest that thyme oil induces resistance against B. cinerea through the priming of defense responses in apple fruit, and the PR-8 gene of apple may play a key role in the mechanism by which thyme essential oil effectively inhibits gray mold in apple fruit.

The effect of biofumigation, through slow-release diffusors, of thyme and savory essential oils (EO), was evaluated on the control of postharvest diseases and quality of peaches and nectarines. EO fumigation was effective in controlling postharvest rots. Naturally contaminated peaches and nectarines were exposed to EO vapors for 28 days at 0 °C in sealed storage cabinets and then exposed at 20 °C for five days during shelf-life in normal atmosphere, simulating retail conditions. Under low disease pressure, most treatments significantly reduced fruit rot incidence during shelf-life, while, under high disease pressure, only vapors of thyme essential oil at the highest concentration tested (10% v/v in the diffusor) significantly reduced the rots. The application of thyme or savory EO favored a reduction of brown rot incidence, caused by Monilinia fructicola, but increased gray mold, caused by Botrytis cinerea. In vitro tests confirmed that M. fructicola was more sensitive to EO vapors than B. cinerea. Essential oil volatile components were characterized in storage cabinets during postharvest. The antifungal components of the essential oils increased during storage, but they were a low fraction of the volatile organic compounds in storage chambers. EO vapors did not influence the overall quality of the fruit, but showed a positive effect in reducing weight loss and in maintaining ascorbic acid and carotenoid content. The application of thyme and savory essential oil vapors represents a promising tool for reducing postharvest losses and preserving the quality of peaches and nectarines.

The severity of F. oxysporum f.sp. conglutinans on rocket plants grown under simulated climate change conditions has been studied. The rocket plants were cultivated on an infested substrate (4 log CFU g-1) and a non-infested substrate over three cycles. Pots were placed in six phytotrons in order to simulate different environmental conditions: 1) 400-450 ppm CO2, 18-22°C; 2) 800-850 ppm CO2, 18-22°C; 3) 400-450 ppm CO2, 22-26°C, 4) 800-850 ppm CO2, 22-26°C, 5) 400-450 ppm CO2, 26-30°C; 6) 800-850 ppm CO2, 26-30°C. Substrates from the infested and control samples were collected from each phytotron at 0, 60 and 120 days after transplanting. The disease index, microbial abundance, leaf physiological performances, root exudates and variability in the fungal profiles were monitored. The disease index was found to be significantly influenced by higher levels of temperature and CO2. Plate counts showed that fungal and bacterial development was not affected by the different CO2 and temperature levels, but a significant decreasing trend was observed from 0 up to 120 days. Conversely, the F. oxysporum f.sp. conglutinans plate counts did not show any significantly decrease from 0 up to 120 days. The fungal profiles, evaluated by means of polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE), showed a relationship to temperature and CO2 on fungal diversity profiles. Different exudation patterns were observed when the controls and infested plants were compared, and it was found that both CO2 and temperature can influence the release of compounds from the roots of rocket plants. In short, the results show that global climate changes could influence disease incidence, probably through plant-mediated effects, caused by soilborne pathogens.

Aflatoxins are a group of secondary metabolites produced by members of Aspergillus Section Flavi that are dangerous to humans and animals. Nuts can be potentially contaminated with aflatoxins, often over the legal threshold. Food processes, including roasting, may have different effects on mycotoxins, and high temperatures have proven to be very effective in the reduction of mycotoxins. In this work, two different roasting methods—traditional static hot air roasting and infra-red rays roasting—were applied and compared for the detoxification of hazelnuts from Italy and Turkey. At the temperature of 140 °C for 40 min of exposure, detoxification was effective for both roasting techniques. Residual aflatoxins after infra-red rays treatments were lower compared to static hot air roasting. On Italian hazelnuts, residual aflatoxins were lower than 5%, while for Turkish hazelnuts they were lower than 15% after 40 min of exposure to an infra-red rays roaster. After roasting, the perisperm was detached from the nuts and analyzed for aflatoxin contents. Residual aflatoxins in the perisperm ranged from 80% up to 100%. After roasting, the lipid profile and the nutritional quality of hazelnuts were not affected. Fatty acid methyl esters analyses showed a similar composition for Italian and Turkish hazelnuts.

Aflatoxins, produced by Aspergillus flavus and A. parasiticus, can contaminate different foodstuffs, such as nuts. Cold atmospheric pressure plasma has the potential to be used for mycotoxin detoxification. In this study, the operating parameters of cold atmospheric pressure plasma were optimized to reduce the presence of aflatoxins on dehulled hazelnuts. First, the effect of different gases was tested (N2, 0.1% O2 and 1% O2, 21% O2), then power (400, 700, 1000, 1150 W) and exposure time (1, 2, 4, and 12 min) were optimized. In preliminary tests on aflatoxin standard solutions, this method allowed to obtain a complete detoxification using a high power for a few minutes. On hazelnuts, in similar conditions (1000 W, 12 min), a reduction in the concentration of total aflatoxins and AFB1 of over 70% was obtained. Aflatoxins B1 and G1 were more sensitive to plasma treatments compared to aflatoxins B2 and G2, respectively. Under plasma treatment, aflatoxin B1 was more sensitive compared to aflatoxin G1. At the highest power, and for the longest time, the maximum temperature increment was 28.9 °C. Cold atmospheric plasma has the potential to be a promising method for aflatoxin detoxification on food, because it is effective and it could help to maintain the organoleptic characteristics.

Effects of increased CO2 and temperature on powdery mildew (Podosphaera xanthii) of zucchini (Cucurbita pepo), were evaluated under controlled conditions. Zucchini plants were grown in phytotrons under four different simulated climatic conditions: 450 ppm of CO2 at standard (18°C night, 24°C day) and elevated temperatures (22°C night, 28°C day), elevated CO2 (800 ppm) with standard temperature and elevated CO2 (800 ppm) with elevated temperature (4°C higher than standard). Physiological responses of zucchini and pathogen development were studied. Under elevated CO2 both healthy and infected zucchini plants grew better when temperature was lower. Elevated CO2 generally caused no significant differences in pathogen development or disease severity, whereas elevated temperature stimulated the development of the pathogen. A combination of elevated CO2 and temperature always stimulated the development of the pathogen and disease severity compared to standard conditions.

Sclerotinia homoeocarpa F.T. Bennett is one of the most important pathogens affecting high maintenance turfgrass in Italy. Control of this pathogen still relies on the use of fungicides. Twenty nine isolates of S. homoeocarpa collected from 13 different golf courses in northern and central Italy were tested in vitro for their sensitivity to propiconazole, tebuconazole and iprodione, fungicides registered for use on turfgrass in Italy. Three isolates from untreated turfgrasses were use as reference isolates. The tests were carried out on an agar medium amended with 0, 0.01, 0.03, 0.1, 0.3, 1, 3, 10, 30, 100, 300 µg mL–1 of the active ingredient of each fungicide. Most of the isolates showed reduced sensitivity to the tested fungicides, while maintaining their virulence when inoculated on potted Agrostis stolonifera L. Fungicide resistance in this pathogen has increased in Italy compared with the situation 10 years previously.

In recent years a postharvest disease of kiwifruit, characterized by skin pitting appearing after 3 or more months of storage, and caused by C. luteo-olivacea, has been reported in most Italian packinghouses. Forty-four strains isolated from kiwifruit harvested in Italy during the period 2001-2009 were tested for their pathogenicity on kiwifruit, apple and pear. The pathogenicity tests showed that different isolates of C. luteo-olivacea were pathogenic on the three fruit species stored at 1°C for 120 days with various degree of virulence. A PCR-based method to identify the pathogen species in kiwifruit was developed. Sequencing of the internal transcribed spacer (ITS1, 5.8S gene and ITS2) region of the rDNA (ITS) showed high similarity with the species C. malorum, agent of side rot of apples and pears. Variation within the ITS was used to design one reverse primer common to both species and two species specific forward primers to specifically identify isolates of C. luteo-olivacea and C. malorum. Both SCAR (sequence characterized amplified region) primer pairs showed to be specific for either Cadophora species when cross-tested and assessed on other species of Cadophora or on species of typical postharvest pathogens of kiwifruit, apple and pear.

The effect of silicon on powdery mildew, caused by Oidium neolycopersici, was evaluated in five trials using two cultivars of tomato, ‘Ikram’ or ‘Cuore di bue’, grown in hydroponic systems. Silicon, as potassium silicate, was added at 100 mg L-1 of nutrient solution at three levels of electrical conductivity; 1.8–2 mS cm-1 (EC1), 3.9–4 mS cm-1 (EC2, 0.87 g L-1 NaCl) and 5–5.5 mS cm-1 (EC3, 1.74 g L-1 NaCl). Tomato plants were first inoculated with O. neolycopersici conidia 15–20 days after transplanting, with a maximum of five inoculations before final disease assessment. Drip or sub-irrigation methods, compared in two of the five trials, did not affect powdery mildew incidence and severity on leaves, 60 or 90 days after the first inoculation. The addition of NaCl to the nutrient solution generally reduced the incidence and severity of powdery mildew, with 0.87 or 1.74 g L-1 NaCl providing a similar effects. The addition to the nutrient solution of potassium silicate resulted in a signifi cant reduction of powdery mildew incidence and severity at the EC2 conductivity tested in all trials. The addition of potassium silicate to the control nutrient solution resulted in a similar or better level of powdery mildew management than the use of a nutrient solution with higher conductivity but no added with potassium silicate. The possibility and benefits of applying potassium silicate amendments in practice are discussed.

Twenty-nine strains of Fusarium oxysporum isolated from wilted lamb’s lettuce plants (Valerianella olitoria) along with eight ATCC reference strains were examined for differences in the nucleotide sequences of the ribosomal DNA (rDNA) intergenic spacer (IGS) region, which is about 2.5 kb long in these strains. A phylogenetic (neighbour-joining) analysis was performed on the strains and identified four phylogenetic groups, I, II, III, and IV. Most F. oxysporum isolates recovered from wilted lamb’s lettuce plants cultivated in northern Italy clustered in group I and were very similar to F. oxysporum f. sp. raphani. All the isolates, including the 8 control strains, were tested for pathogenicity on lamb’s lettuce cv. Trophy cultivated in the glasshouse. Most isolates from northern Italy were pathogenic on lamb’s lettuce, displaying varying degrees of virulence, and their IGS sequence were similar to the forma specialis raphani. However, four isolates were not pathogenic on lamb’s lettuce. Among the control strains, six showed moderate virulence; these belonged to the formae speciales raphani and conglutinans; and two, belonging to the forma specialis matthioli (ATCC16602 and ATCC16603) were not pathogenic on lamb’s lettuce. In conclusion, analysis of the IGS sequences indicated that the isolates studied had different origins, and that phylogeny and pathogenicity were related; non-pathogenic isolates differed genetically from isolates that were poorly, moderately or highly virulent. To the best of our knowledge, this is the first report on the differences between formae speciales of F. oxysporum on lamb’s lettuce plants as determined by IGS sequence analysis.

Aspergillus carbonarius colonizes grapes and its derived products and produces ochratoxin A (OTA). In previous studies we screened 107 strains of A. carbonarius isolated from grapes for production of OTA, and we selected three high OTA-producing strains for this study (AC05, AC06, and AC07). The effect of different values of three conditions [temperature 15, 25, 30, 35°C; water activity (aw) 0.98, 0.95, 0.90, 0.88; and pH 4.0, 7.0, 9.0, 10.0] on A. carbonarius growth and OTA production was examined. A. carbonarius AC07 produced higher levels of OTA than AC06 and AC05 at all the variables tested. At 30°C the strains of A. carbonarius produced more OTA than at the other temperatures. A water activity of aw 0.98 produced the greatest mycelial growth and OTA accumulation for all three A. carbonarius strains. A pH of 4.0 produced the highest levels of OTA in all the strains. No growth was seen at aw 0.88 or at pH 10.0 in any strain, except AC07, which grew at pH 10.0. The optimal conditions for growth and production of OTA by A. carbonarius strains were 30°C, aw 0.98 and pH 4.0. When all the three factors (aw, pH, T) were combined, aw 0.98, pH 4.00 and 30ºC produced the highest levels of OTA in all the strains. Maximum amounts of OTA were found 7–9 ays after inoculation in all the strains. Temperature, water activity, and pH had a great impact on OTA production by A. carbonarius and these factors should be taken into account when developing management practices for future research programmes.

The importance of a shift toward agricultural systems, which are more complex in terms of biodiversity in emerging countries such as China, where most of the population (about 60%) lives in rural areas, in poor conditions and still relies on agriculture as the main source of income, is discussed. In China the problems caused by shifting to more intensive and polluting agricultural production patterns to address the demand for food of the growing population and by the need of higher incomes of rural communities are serious. The experience gained in the framework of the Sino-Italian Cooperation Program for Environment Protection jointly launched by the Italian Ministry for the Environment and Territory (IMET) and the State Environment Protection Administration of China (SEPA) in the year 2000, through the implementation of several cooperation projects in different rural areas of China is critically discussed.

Seven glasshouse experiments were set up in 1995–1999 to evaluate the efficacy of various treatments in reducing the incidence of “stanchezza” (soil sickness) of sweet basil, an emerging phytopathological problem in the main basil-growing areas of Italy. Complete or partial replacement of the soil was generally effective in increasing plant size and fresh weight of both roots and aerial parts. Steam disinfestation of the soil abolished the symptoms of “stanchezza” during the first growth cycle, but its effect was reduced on the second crop. Leaching the substrate with water and deep tilling had no or only limited effect on plant growth. Amendment with a commercial biostimulating product containing organic phenolic compounds had only partial efficacy. Bench solarization was the most effective means of control of the syndrome and its effect continued for the second crop cycle. No significant reduction of “stanchezza” was achieved with broad-spectrum antibiotic or fungicide mixtures. No significant differences were detected between bacterial and fungal populations in a soil with “stanchezza” and a non-cultivated soil. Further investigation is now required to shed light on the mechanisms underlying this emerging phytopathological problem.