Search

Durum wheat production in Italy is of great importance from an economic point of view. In Italy, Fusarium graminearum is the main fusarium head blight (FHB) causal agent in wheat, reducing both grain quality and yield. F. graminearum produces trichothecene mycotoxins such as deoxynivalenol (DON) and nivalenol (NIV) that are toxic for humans and animals. A population of F. graminearum sensu stricto strains was collected from symptomatic durum wheat heads and grains from several naturally infected fields in different Italian regions such as Emilia Romagna, Lazio, Marche, Piemonte, Sardegna, Umbria and Veneto. A multiplex PCR in the Tri12 region of the trichothecene gene cluster was used to assign a strain to one of trichothecene chemotype profiles: NIV, 3-acetyldeoxynivalenol (3ADON) and 15-acetyldeoxynivalenol (15ADON). In order to evaluate possible mycotoxin contamination risks it is very important to know which chemotype is the prevalent in a F. graminearum population. Our research showed that the15ADON chemotype was the most frequent. This work, performed for the first time in Italy, allowed us to better understand the distribution of the F. graminearum chemotypes.

Fusarium graminearum is one of the main causal agents of fusarium head blight (FHB) in Italy. A population of 74 F. graminearum strains was collected from symptomatic durum wheat spikes from different fields around Bologna (Emilia-Romagna, northern Italy) between 2006 and 2008. The data obtained showed that the F. graminearum population is variable in an homogeneous restricted geographical area. F. graminearum sensu stricto strains were examined using specific primers for chemotypes based on the production of the trichothecenes deoxynivalenol (DON) and nivalenol (NIV). The strains were analyzed by multiplex PCR in the Tri12 sequence of the trichothecene gene cluster and assigned to one of three profiles of trichothecene chemotypes. All three fungal chemotypes were found. The 15-acetyldeoxynivalenol (15ADON) chemotype was the most frequent (87.2%), followed by the 3-acetyldeoxynivalenol (3ADON) (8.1%) and NIV (2.7%) chemotypes. The variability of the strains in such a restricted area leads us to hypothesize that there is similar variability of F. graminearum throughout Italy.

Fusarium head blight (FHB) of wheat is a very insidious disease caused by several fungal species prevalently belonging to the Fusarium genus. In Italy it has been permanently present since 1995. The most frequent species of Fusarium in wheat ears are F. graminearum and F. culmorum, but the composition of the population of Fusarium associated to this disease in the Emilia Romagna region, Northern Italy, has changed during the years. Our study has revealed the increased frequency of other Fusaria such as F. poae. The Fusarium species involved are responsible for yield losses and decreasing in grain quality characteristics, including the accumulation of mycotoxins, capable of harming the health of humans and animals. The F. graminearum strains were examined using specific primers for chemotypes based on the production of the trichothecenes, deoxynivalenol (DON) (15ADON and 3ADON) and nivalenol (NIV). The F. poae strains are also able to produce an extensive range of mycotoxins. In this work we found F. poae strains able to produce T-2 toxin, which is the most dangerous among all the trichothecenes of the classes A and B, and its derivative HT-2. The aim of the present work was to characterize the Fusarium strains for their ability to produce different mycotoxins and to test for their interaction by experimental trials, in order to control Fusarium head blight and limit the contamination of grains with mycotoxins.

Durum wheat is an important crop in Europe for its impact on agriculture and can be affected by fusarium head blight (FHB). Several are the species of Fusarium involved in this disease, in Italy the most frequent are: F. graminearum, F. culmorum, F. avenaceum and F. poae. Another causal agent is Microdochium nivale var. majus and var. nivale synonim of F. nivale. Some Fusarium species associated to FHB are responsible for losses in seed quality characteristics including the accumulation of mycotoxins. The fusarium toxins, deoxynivalenol - DON, nivalenol - NIV, zearalenone - ZEN, are a serious problem in Europe and in the world and their presence is related to agronomic and environmental conditions. Our study on FHB durum wheat heads collected in fields in Emilia-Romagna, Italy, since 1995, revealed three main species of Fusarium: F. graminearum (mean value 32.1%), F. culmorum (mean value 25.2%) and F. poae (mean value 17.9%). A population of F. graminearum was examined for chemotypes based on the production of the trichothecenes DON and NIV. Three chemotypes - 15-AcDON, 3-AcDON and NIV - were observed and the most representative was 15-AcDON. Some fungicides, Bromuconazole (Granit®), prochloraz (Sportak®45 EW) and tebuconazole (Horizon®), applied in experimental trials, reduced disease incidence and severity. The use of these products, other than controlling the disease, reduced fusarium infected kernels and DON content in durum wheat chain in the global market (i.e. semolina, bran). Therefore in terms of technologies and food safety, it is important to set up strategies to control FHB not only with chemical products but also with an integration of a series of correct agronomic practices, which reduce the primary inoculum, since these toxins represent a known and potential hazard to human and animal health, through the consumption of contaminated food.

An unusual disease, named elephantiasis for its typical symptoms, has been seen in orchards of kiwifruit cv. Hayward in Emilia-Romagna (northern Italy) since 2001. Phialophora-like isolates were obtained from the necrotic wood and were studied in vitro for phenotype and tissue colonization ability. We used primers amplifying the internal transcribed spacer (ITS) region of the ribosomal DNA (rDNA) for molecular identification. Phaeoacremonium strains were further identified with b-tubulin-specific primers. Strains of Cadophora, Lecythophora and Phaeoacremonium were classified and characterized. The isolates differed in their ability to colonise tissue. P. aleophilum and C. melinii showed the highest colonization index. To our knowledge, this is the first report of Cadophora melinii isolated from kiwifruit plants.

Zymoseptoria tritici, a globally distributed pathogen, is responsible of Septoria tritici blotch (STB), one of the most damaging wheat diseases. In Italy the incidence of STB has increased during the past few years. The presence of Z. tritici on flag leaves of susceptible durum wheat plants, cultivar San Carlo, after a single artificial inoculation with two inoculum concentrations at different vegetative stages has been evaluated in the plain of Bologna (North of Italy), in a two year field study (2012–2013). The pathogen presence was also assessed in natural infection conditions after a fungicide application in the second year (2013). The results obtained, by visual examination (Incidence, Disease Severity) and DNA quantification by Real time PCR, demonstrated that BBCH 39 (flag leaf stage) is the most susceptible vegetative stage, independently of inoculum concentration and climatic conditions. A good correlation between Disease Severity and DNA quantity was observed in either sampling methods, entire flag leaves and flag leaf discs. Thereafter the most suitable period to obtain the best crop protection with only one fungicide treatment is the flag leaf stage.

Root and crown rot of wheat, caused by Fusarium culmorum (Fc), is a serious disease worldwide, particularly in Iran. Currently, the mechanisms underlying resistance to Fusarium-caused diseases are still unknown. Methyl jasmonate (MeJA) has been identified as a vital cellular regulator, and the effect of exogenous MeJA application during wheat-Fc interaction has not been studied previously at the molecular level. This study, using real-time quantitative PCR, was carried out to determine the expression of seven host defense-associated genes consisting of PR3, PR4, PR5, TaPERO, LOX, PAL and cytochrome P450 gene (CYP709C1) at 48, 72 and 96 h after Fc-inoculation (hai) and to investigate the relationship between the induced resistance by MeJA application and the gene expression patterns. The results showed that several genes were induced earlier (48 hai) and to higher levels in the resistant cv. Sumai3 than in susceptible cv. Falat. Many Fc-induced genes were also activated and induced by MeJA particularly during the later stages of infection; however, in contrast to defense-gene induction by the pathogen, there was not a general trend of higher induction in Sumai3 compared to Falat following this chemical treatment. The chemically induced protection significantly reduced the development of necrotic symptoms in both cultivars over a 3-week period after inoculation; however, this reduction was greater in Falat than in Sumai3 relative to the controls. Surprisingly, the expression of these genes was also expressed in crown tissue that had not yet been in contact with the fungus, signifying that a form of systemic response was taking place in this interaction. This is the first work reporting the effect of timing application of MeJA during Fc infection and comparing the defense-related gene expression between root and crown tissues of wheat genotypes. Moreover, soil-drench application of MeJA resulted in strong induction, verifying the success of this application method in systemically activating JA signaling for the first time. These results provided important intimations for designing strategies to curtail diseases caused by Fusarium.

Wheat is one of the most important crops in Syria, for both local consumption and export commodity and can be infected by Fusarium Head Blight (FHB) a world-widespread disease. Fusarium Head Blight reduces yield, grain quality and causes accumulation of deoxynivalenol (DON). The most promising and effective management strategy is to avail cultivars resistant to FHB. Ten Syrian durum wheat cultivars and "Simeto", one of the most susceptible Italian cultivars, were artificially infected, under growth chamber and field conditions. They were inoculated with Syrian and Italian strains of Fusarium culmorum, one of the main agents of FHB, to screen their tolerance toward FHB infection, FHB spread, kernel infection and mycotoxin levels. Jory was the most tolerant cultivar in the growth chamber and field, while Sham 9, was the most susceptible.

Fusarium culmorum is a soilborne fungal pathogen, agent of crown and root rot disease (FCRR), responsible of major economic losses in wheat plants. This host-pathogen interaction, following methyl jasmonate (MeJA) application at the beginning of the necrotrophic stage of infection, has not been previously studied at molecular level. In this study, using real-time quantitative PCR, the emerging role of MeJA in the basal resistance of two bread wheat cultivars against F. culmorum has been investigated. MeJA treatment was dispensed 6 hours after pathogen inoculation (6 hai) to detect the defense response at the beginning of the necrotrophic stage. The expression of phenylalanine ammonia-lyase (PAL), lipoxygenase (LOX), cytochrome P450 (CYP709C1) genes and of some pathogenesis related (PR) genes, including PR3, PR4 and PR9, was examined in both root and crown tissues of the susceptible wheat cultivar Falat and the tolerant cultivar Sumai3. The pathogen responsive defense genes were induced in both cultivars, with a higher level of induction in Sumai3 than in Falat. MeJA treatment reduced the symptoms in cv Falat, whereas no significant effects have been detected in cv Sumai3. In fact, MeJA treatment caused a striking difference in defense gene induction. The genetic change was present in root and crown tissues of both wheat cultivars, demonstrating a systemic signaling pathway. The chemically induced protection correlated with induction of the F. culmorum-responsive genes supports a possible role of jasmonate signaling in regulating basal resistance in wheat-F. culmorum interaction.

Dipartimento di Scienze Agrarie e Ambientali, Universita degli Studi di Perugia, Borgo XX Giugno, 74, 06121 Perugia, Italy (Received on June 24, 2011; Revised on October 13, 2011; Accepted on October 16, 2011)Chemotype composition of Fusarium graminearumstrains, isolated from durum wheat kernels fromnaturally FHB infected fields in Northern and CentralItaly, was investigated by multiplex PCR. The differentclimatic and environmental conditions of the twoexamined areas separated by the Apennines affected thecomposition of chemotypes. 15Ac-DON chemotype waspredominant in both the sub areas. Nivalneol chemo-type was more frequent in the warmer sub area.Keywords :chemotype, durum wheat, Fusarium graminearum,Fusarium head blightFusarium graminearum (teleomorph Gibberella zeae(Schwein.) Petch.) is the major pathogen responsible ofFusarium head blight (FHB), an economically crucial andcomplex etiology disease on cereal crops worldwide(Goswami and Kistler, 2004). FHB has received moreattention because of its effect on yield (Parry et al., 1995),grain quality (Liggitt et al., 1997) and grain contaminationby mycotoxins (Visconti et al., 2000). FHB resistantcultivars are considered one of the solutions for the problemrelated to mycotoxin contamination in wheat grains (Lemmenset al., 2004), but unfortunately to date no resistant cultivar iscommercially available for durum wheat. Most attention inthe analysis of grain affected by FHB was placed oncontamination by deoxynivalenol (DON), acetylated formsof DON (3Ac-DON and 15Ac-DON) and nivalenol (NIV).DON is a mycotoxin that disturbs and/or inhibits DNA,RNA and protein synthesis by binding to the ribosomalpeptidyltransferase site leading to a decrease of cell pro-liferation (Shifrin and Anderson, 1999). It is also known asvomitoxin and it is responsible for hemorrhagic andanorexic syndromes, neurotoxic and immunotoxic effectsin mammals (Visconti et al., 2004). DON contaminationlevels in food and feed were found to be much higher thanthose observed for NIV (Boutigny et al., 2011), beingprobably the most negligible toxin due to the small amountusually detected (Yazar and Omurtag, 2008), but withconsistent levels in many Asian countries, New Zealandand Brazil (Placinta et al., 1999). However, NIV has shownto have a higher toxicity than DON, for example, in humanblood cells (Minervini et al., 2004). This toxin has alsoshown higher activity than DON in inhibiting DNA, and itmay account for various toxic phenomena such as inductionof cell death (Poapolathep et al., 2002). Based on the production of type B trichothecenes, DONand NIV, three F. graminearum chemotypes have beendescribed: 3Ac-DON, 15Ac-DON and NIV. Chemotypeidentification is broadly used to characterize F. graminearumfor its toxigenic potential (Pasquali et al., 2009). There wasa correlation between the presence of F. graminearumchemotype and wheat grain mycotoxin content. DON andNIV contents can be successfully predicted by quantifyingthe fungal biomass of DON and NIV producers with a real-time PCR quantification method (Brandfass and Karlovsky,2006; Burlakoti et al., 2007; Pasquali et al., 2009). The dominant chemotypes of F. graminearum varywithin geographical areas, i.e. different countries and/orcontinents (Prodi et al., 2009b), but some host preferencemay affect the composition of chemotypes of F. grami-nearum population. Within the same country, the differentgeographical areas (i.e. plain, mountains, valleys, etc.) anddistances from the sea, may also affect the composition ofchemotypes of a fungal population. Mountains may play animportance role as natural obstacles by inhibiting the

Septoria tritici blotch (STB) is one of the most damaging disease of wheat caused by Zimoseptoria tritici (formerly known as Mycosphaerella graminicola / Septoria tritici) and worldwide spread. SBT is the most important foliar disease of wheat in America, Asia, Northern, Central Europe and it is a major disease, particularly on durum wheat, in North Africa. In Italy the average severity of STB infection, detected from 2000 up to 2015 on durum wheat varieties, has shown an exponential growth trend, that reached its peak between 2007-2010 with a further peak in 2013 and a slight decline in the last two marketing years. In the plain area environment of Bologna (Emilia Romagna region - North of Italy) the infection is due to Z. tritici with yield losses of 30% in years with high inoculum pressure. The aim of this study has been to evaluate, in the plain of Bologna, in two years field trial, the presence of Z. tritici on the flag leaf in San Carlo, a susceptible Italian durum wheat cultivar, after a single artificial inoculation at different vegetative stages (BBCH 31, 35, 39, 60) with two different inoculum concentration (105 and 106 conidia/ml). Visual assessments (Incidence, Disease severity -DS) and DNA quantification by Real time PCR, using the primer pair ST-rRNA F/R (Guo et al., 2006; Presymptomatic and quantitative detection of Mycosphaerella graminicola development in wheat using Real Time PCR. FEMS Microbiol Lett 262:223-229), were set up. The results demonstrate that the BBCH 39 is the most susceptible stage, independently by the concentration of inoculum and climatic conditions: the year 2012 was characterized by a low infection pressure of the pathogen, while year 2013 was characterized by a high infection pressure. In the 2013 a good correlation between DS and DNA quantity was observed. The results obtained point out that the most suitable period to obtain the best crop protection could be the flag leaf stage, even if Northern Italian farmers perform the fungicide treatment against STB earlier, at BBCH31 in association with the herbicide treatment, because cost-effective.

During 2011, Fusarium rot of stored garlic was detected on bulbs of ‘Aglio Bianco’ (white garlic) in Piacenza, Ferrara and Rovigo districts. Bulbs, harvested in July, were asymptomatic. During conservation in the drying sheds, approximately thirty percent of bulbs appeared emptied and softened. Fusarium proliferatum was consistently recovered from infected bulbs. The morphological identification was confirmed by Translation Elongation Factor 1-alpha gene sequencing. Koch postulates were checked through pathogenicity tests. The disease has already been reported in Serbia, Germany, Spain, United States, China and India, but to our knowledge, this is the first report of F. proliferatum garlic bulb rot in Italy.

Fusarium Head Blight caused by phytopathogenic Fusarium spp. with Fusarium graminearum as main causal agent is a major disease of durum wheat (Triticum durum Desf.). Mycotoxins in wheat are dominated by trichothecenes B. Fumonisins have only occasionally been reported from wheat; their occurrence was attributed to Fusarium proliferatum and Fusarium verticillioides. We investigated kernels of durum wheat grown in Italy in 2008 - 2010 for colonization with Fusarium spp. and for the content of Fusarium mycotoxins. Fungal biomass was determined using species-specific qPCR and mycotoxins were quantified by HPLC-MS/MS. Fusarium graminearum and Fusarium culmorum were dominating Fusarium species, followed by Fusarium poae, Fusarium tricinctum, and Fusarium proliferatum. No Fusarium verticillioides DNA was found. Toxicologically relevant levels of deoxynivalenol and nivalenol but no trichothecenes A were detected. Enniatins, fumonisin B1 and beauvericin were present in grain in all three years. Based on these results and on the evaluation of previous published reports, we hypothesize that low levels of fumonisins commonly occur in wheat grains produced in warm climate; they may remain undetected as long as mycotoxin monitoring programs for wheat do not include fumonisins. The only relevant source of fumonisins in wheat grain appears to be Fusarium proliferatum., Journal of Applied Botany and Food Quality, Vol 88 (2015): Journal of Applied Botany and Food Quality

Fusarium proliferatum is an emerging, spreading worldwide pathogen of garlic, causing bulb rot. During the whole crop cycle, fungal presence is not associated to characteristic symptoms. During storage, infected bulbs, conversely, undergo to a slow deterioration process: at first brown depressed water soaked spots and, in extremely severe infections, the entire bulbs rot, reducing the garlic shelf-life. The disease leads to appreciable loss of product. This fungus is well known to produce fumonisins. White garlics, cultivated in different northern Italian regions are subjected to mycological and HPLC analysis, to detect the pathogen and quantify the mycotoxins. Basal plate of garlics were dissected and cultured in PDA Petri dishes amended with streptomycin and neomicyn sulphate. Strains morphologically belonging to F. proliferatum species were tested by PCR with specific primers and with primers for Fum1 gene involved in fumonisin production. For mycotoxin analysis, cloves were dried for one week at 40°C, grinded in fine powder and analyzed by IAC/HPLC. F. proliferatum is present in all the tested bulbs and all the strains collected show the presence of FUM1 gene. The Fumonisin levels in cloves ranged from 0,05 ppm to 0.68 ppm for B1 and up to 0.1 for B2. These quite low levels are reached within a short period of conservation in comparison to the time from storage to consumption. Mycotoxin levels should be checked in different food chain steps and on garlic derived products, therefore it is necessary to consider the influence of the conservation time at home, by consumers to better evaluate the possible risk in human health.

A rapid decay of Poplars AF2 clone, Populus x canadiensis, selected for biomass production addressed to produce energy and with an elevated tolerance to several harshnesses, has been observed in year 2013 in three fields (41.5ha) in Bologna Province. These fields were set in March 2010, pruning in two of the three fields was not done at the due time, since plants showed a scarce growth, with an incidence over 80%. Observations and samplings were done on plants of plots (10x10m) of each field. Trunk cross sections of all tested plants showed a central area, at 8cm from the soil, completely necrotic surrounded by a typical reddish ring extended up to 60%. Fungal colonies with fluffy grey mycelium were isolated from woody fragments, plated on agar medium. Their identification through sequencing of partial rDNA ITS region was performed comparing sequences in the NCBI database by BLASTn search algorithm. The nucleotide search comparison showed 98% identity with Cryptosphaeria lignyota (Fr.) Auersw. This fungus has been reported in literature as responsible of wood decay of some plant species, i.e. genus Populus and especially those with rapid growth. It can kill young trees within a year from infection and contributes to natural thinning of trunk formations. It seems that the host death might be due to massive invasion of the sapwood, that prevents it from transporting water and nutrients, and not to annular extension of the canker. The fungus is responsible of a great economic loss being all the infected plants highly compromised.

Fusarium Head Blight (FHB), or scab, is a cereal disease widespread throughout the world and it has been studied mainly in wheat. FHB can cause significant yield losses and quality reductions, especially if during fungal infection dangerous mycotoxins for the human and animal health are produced. In the last years, in Italy, barley production for malting industry has undergone a positive trend that it shifts major attention to the barley diseases. FHB symptoms in barley differ in part from those in wheat. In wheat, premature death or bleaching of spikelets is a typical symptom, particularly clear on emerged immature heads. Pink to salmon-orange spore masses of the fungus are often formed on the infected spikelets and glumes during prolonged wet weather. In barley, symptoms of infection are shown by a bleached appearance too, but also a browning or water-soaked appearance or even a little brown spots on the glume are noticed. Salmon-orange spore masses of the fungus can be rarely observed. In wheat the severity index of the FHB is calculated with the rating scale proposed by Parry et al. (1984) that evaluates the percentage area infected on individual ears with values among 0% and 90%. The aim of this work is to set up a FHB scale for barley, similar to that used by Parry, taking as reference tow-row barley cultivar artificially inoculated in an experimental field. This rating scale can be useful also to the breeders to evaluate the different susceptibility of barley cultivars.

Durum wheat production in Italy is economically of great importance. Fusarium graminearum is the main fusarium head blight (FHB) causal agent in wheat, reducing both yield and grain quality. F. graminearum produces several mycotoxins and, among trichothecenes, deoxynivalenol (DON) and nivalenol (NIV) are the most studied for their toxicity towards humans and animals. DON-producing isolates can be further distinguished on the basis of the predominant acetyl-DON derivative in 3-acetyldeoxynivalenol (3-ADON) or 15-acetyldeoxynivalenol (15-ADON). In order to evaluate possible mycotoxin contamination risks in food, it is very important to know which chemotype is the prevalent in a F. graminearum population. F. graminearum sensu stricto strains were collected from symptomatic durum wheat heads and grains of several naturally infected fields located mostly in Emilia - Romagna, The Marche, Lazio, Tuscany and Umbria. A multiplex PCR in the region of genes Tri12, located in the terminal gene cluster of trichothecenes, was used to characterize 187 single-spore isolates of F. graminearum as NIV, 3-ADON and 15-ADON chemotypes. All the three chemotypes were present in the F. graminearum population studied. The most frequent chemotype was 15-ADON (83.4%), followed by 3-ADON (10.7%) and NIV (5.9%). NIV-producing isolates were found only in Emilia-Romagna (3.5%), Umbria (33.3%) and The Marche (5.7%).

Recenti infezioni a carico di rucola coltivata e selvatica in Italia sono state causate da Fusarium oxysporum f. sp. raphani. Considerando che i miceti riferibili alla specie F. oxysporum sono agenti di deperimenti o marciumi radicali su centinaia di ospiti vegetali, distinti sulla base di risposte ospite specifiche in formae speciales e che la specie è ubiquitaria e cosmopolita, risulta difficile effettuare una identificazione tempestiva e certa con il solo approccio morfologico. L’esatta identificazione degli agenti causali è punto cruciale nella valutazione della sanità delle sementi e nella gestione di questa problematica. Nel presente lavoro sono stati analizzati 39 lotti di semente, di cui 31 di rucola selvatica e 8 di rucola coltivata, su substrato semiselettivo (Komada’s medium) per la ricerca di Fusarium spp. Da questi lotti sono stati reperiti 24 isolati, che, unitamente a 2 ceppi di riferimento, sono stati saggiati biologicamente tramite prove di patogenicità differenziali in ambiente controllato e caratterizzati molecolarmente sulla base dello studio dei geni ITS e EF-1. Nessun isolato da seme, analizzato in questa indagine, risulta appartenere a F. oxysporum f. sp. raphani e la maggioranza dei ceppi fungini isolati appartiene a Gibberella fujikuroi Complex.

The economical importance of “ready to use” fruit and vegetable products (4th range), greatly increased in the last ten years; to date Lactuca sativa, Cichorium spp., Eruca sativa, Diplotaxis spp and Valerianella locusta cover a great part of the vegetable market. The final products quality can be achieved using healthy seeds and appropriate agronomic techniques. One of the most important pathogens of these species is Fusarium oxysporum: infected plants are usually stunted, leaves turn pale green to golden yellow and later wilt, wither, die and drop off progressively upward from the stem base. Browning occur in vascular tissue (xylem) of roots and lower stem, while roots may decay and seedlings sometimes wilt and die. Surviving seeds can act as source of primary inoculum. In the present work more than 100 seed lots of Diplotaxis spp., Eruca sativa, Lactuca spp. and Valerianella locusta have been analyzed, in order to assess the incidence of F. oxysporum on commercial seeds. Our data highlight the very low frequency of F. oxysporum infection and the presence of other Fusarium species belonging to Gibberella fujikuroi complex.

Fusarium head blight (FHB) is a very important cereal fungal disease. In Italy, it has been permanently present in wheat since 1995. The most frequent species of Fusarium causing the disease are F. graminearum, F. culmorum and recently F. poae. These species are responsible for yield losses and decreasing grain quality characteristics, including the accumulation of mycotoxins responsible of serious health effects to humans and animals. The most dominant F. graminearum mycotoxins are the trichothecenes, with deoxynivalenol and nivalenol being the most prevalent derivatives. F. poae is able to produce an extensive range of mycotoxins and, in some cases T-2 toxin and its derivative HT-2. T-2 toxin is the most dangerous among all trichothecenes of classes A and B, with an LD50 value 20-times lower than deoxynivalenol. F. graminearum and F. poae strains, producing different mycotoxins, were tested for their interaction in vitro and in vivo trials. The strains were inoculated singularly or mixed in a durum wheat cultivar sensible to FHB. The incidence and the severity of the disease were also evaluated. In the flour obtained from the grains, real-time PCR and HPLC-MS were used to estimate the biomass of F. graminearum/F. poae and determine the amounts of mycotoxins, respectively. The aim of this work was to investigate the direct interaction between F. graminearum and F. poae, which might substantially contribute to the population dynamic of these species in the field. The interest of the scientific community in F. poae has been steadily growing due to its potential to produce dangerous mycotoxins. In order to control Fusarium head blight and limit the contamination of grain with mycotoxins, we need to better understand the role of F. poae in the disease and its ecology including interaction with other pathogens colonizing wheat ears.

Fusarium head blight (FHB) is the main worldwide wheat disease. In Emilia-Romagna region (Northern Italy), the most frequent species responsible of FHB on durum wheat were Fusarium graminearum and F. culmorum since 1995. FHB can cause losses in production (0.6-2.7 t/Ha) and seed quality, due to kernel infection and micotoxin accumulation. From 2000 to 2006, some DMI commercial fungicides were evaluated for their efficacy in controlling FHB incidence and severity, percentage of infected kernels and deoxynivalenol (DON) content in kernels. DMI were applied at anthesis stage (GS 60-61), in several cultivars of durum wheat, inoculated artificially with a mixture of F. graminearum and F. culmorum toxigenic isolates. Trials, on fourteen cultivars with bromuconazole, prochloraz and tebuconazole were performed from 2000 to 2002 and on four cultivars with epoxiconazole + prochloraz, cyproconazole + prochloraz, metconazole (not yet registered in Italy) from 2005 to 2006. These fungicides significantly reduced incidence and severity of FHB compared with the untreated control. The results showed an average efficacy in reducing the tested parameters of 53% and 68% respectively in the first experiment, 64% and 59% in the second. From 2000 to 2002 on six durum wheat cultivars, bromuconazole, prochloraz and tebuconazole significantly reduced the percentage of F. graminearum and F. culmorum infected kernels by averagely 63% and DON content of 66%, when compared with the untreated control. The knowledge of DMI efficacy in reducing FHB incidence and severity, infected kernels and DON content is very important for setting up disease control strategies.

Fusarium oxysporum f. sp. raphani è stato definito come agente causale del deperimento della rucola coltivata (Eruca sativa) e della rucola selvatica (Diplotaxis spp.) in Italia (Garibaldi et al., 2003). La principale fonte di diffusione, a lunga e a breve distanza, di questa tracheomicosi sembra essere il seme (Garibaldi et al., 2005). L’esatta identificazione degli agenti causali è punto cruciale nella valutazione della sanità delle sementi e nella gestione di questa problematica. Considerando che i miceti riferibili alla specie F. oxysporum sono agenti di deperimenti o marciumi radicali su centinaia di ospiti vegetali, distinti sulla base di risposte ospite specifiche in “formae speciales”, che la specie è ubiquitaria e cosmopolita, risulta difficile effettuare una identificazione tempestiva e certa con il solo approccio morfologico. Nel presente lavoro sono stati analizzati 49 lotti di semente, di cui 37 di rucola selvatica e 12 di rucola coltivata, su substrato semiselettivo (Komada’s medium) per la ricerca di F. oxysporum. Per l’individuazione di F. oxysporum f. sp. raphani, i 21 isolati collezionati, unitamente a 2 ceppi di riferimento, sono stati saggiati biologicamente tramite prove di patogenicità differenziali in ambiente controllato e caratterizzati molecolarmente sulla base dello studio dei geni ITS e TEF. Nessun isolato da seme analizzato in questa indagine risulta appartenere a F. oxysporum f.sp. raphani.

F. semitectum is a filamentous fungus showing remarkable characteristics, like the adaptability to a great range of hosts and environments and the unique metabolites production pattern. Its importance is proved by the crescent number of scientific papers published in the last years regarding this species. F. semitectum infections were reported in cotton, banana, alfalfa, melon, soybean. This fungus was also isolated from rice, but its pathogenicity still has to be proved. F. semitectum can produce fibrinolytic enzymes, mycotoxins (type A trichotecenes, zearalenone), antibiotics (equisetin, epi-equisetin) and a broad range of metabolites with antifungal (fusapyrone, deoxyfusapyrone) or zootoxic (beauvericin) activity. In the present work we set up a new laboratory protocol for the molecular identification of this fungus. RAPD (Random Amplified Polymorphic DNA) technique was used to identify a species-specific amplification product. RAPD was combined with a fast DNA extraction method that generated reproducible band patterns. The selected fragment was cloned, sequenced and a primer pair (Fs1, Fs2) was developed to specifically detect F. semitectum using conventional PCR. The new SCAR marker was used to perform a mycological screening on rice, a species of great economical importance in Northern Italy.

Fusarium graminearum is one of the main causal agents of fusarium head blight (FHB) of wheat. F. graminearum population can be divided into two chemotypes based on the production of the trichothecenes deoxynivalenol (DON) and nivalenol (NIV). DON-producing isolates can be further distinguished on the basis of the predominant acetyl DON derivative that produce: 3-acetyl DON (3-AcDON) or 15-acetyl DON (15-AcDON). In this investigation, the isolates, collected between 2006 and 2007 from symptomatic spikes of durum wheat in several fields located in North of Italy, around Bologna (Emilia-Romagna region), were tested with a multiplex version of the chemotype-specific PCR proposed by Ward et al., 2002. We observed, during our studies, all the three chemotypes in particular 79% of the 66 isolates belonged to the 15-AcDON chemotype, 15 % to the 3-AcDON and 6% to NIV. 15-AcDON chemotype was the most representative. This is the first time that a population of F. graminearum, exclusively isolated from durum wheat from the area under investigation, was examined for chemotype. Taking into consideration the variability of Italian environmental characteristics, it is interesting to monitore fields from all over the country, especially where the durum wheat is more cultivated, to better understand the distribution of the chemotypes in Italy.

L’Actinidia è soggetta a varie malattie a carico del legno e fra queste l’elefantiasi, il cui sintomo caratterizzante è un’ipertrofia del tronco. I frutti prodotti da queste piante hanno forma rotondeggiante e taglia ridotta, parametri che possono limitarne la commercializzazione. Fino ad ora gli studi su questa malattia sono stati rivolti alla individuazione degli agenti causali, mentre le caratteristiche dei frutti sono state scarsamente indagate. In questo lavoro, le modificazioni strutturali e ultrastrutturali nei frutti, da piante con elefantiasi, sono state ricercate mediante le tecniche DRIFT, FT-Raman, NMR e SEM. Le principali variazioni riguardano la componente polisaccaridica.

Fusarium isolates obtained from Iran and Italy were identified by morphological characters and confirmed by using species-specific PCR assays. The genetic chemotyping for each strain, as a preliminary assessment for trichothecene production, was defined using PCR. Subsequently, artificial infection on durum wheat (cv. Normanno) was carried out in the greenhouse to study the pathogenicity and aggressiveness of Iranian, Italian and Syrian F. culmorum strains, the causal agent of crown and root rot of wheat. All F. culmorum strains from Iran and Italy belonged to the 3-acetyl-deoxynivalenol (3Ac-DON) chemotype, while F. culmorum strains from Syria, previously characterized, belonged to the 3Ac-DON and nivalenol (NIV) chemotypes. All of the strains were pathogenic and caused typical Fusarium crown rot (FCR) symptoms. Italian and Iranian strains showed similar mean aggressiveness levels (19.1 and 18.7% respectively), while the mean aggressiveness level for Syrian strains was 11.8%. There were statistically significant differences among the strains. Two Italian strains, F383 and F1126, had the greatest level of aggressiveness while FC9 (Italian) and F961 (Syrian) were the least aggressive strains. No significant differences relating to agro-ecological origin were detected among Iranian, Italian and Syrian strains. This is the first genetic chemotyping characterization and comparison of F. culmorum strains, isolated from different agro-ecological countries, Iran, Syria (Middle East) and Italy (Europe), which has estimated their potential for producing mycotoxins, and the aggressiveness levels of F. culmorum for development of FCR. These results support the increasing concerns about the risk of FCR in many wheat producing countries, particularly in Iran and Syria.