Seed-borne diseases of wheat such as Fusarium head blight (FHB), a fungal disease caused by several species of Fusarium, results in reduced yield and seed quality. The aim of this study was to identify the Fusarium species, the effect of Fusarium-infected seeds on germination and vigor indices and to determine the location of Fusarium spp. in seeds, as well as to investigate the pathogenicity and variability of aggressiveness of the isolates obtained from pre-basic seeds wheat fields in Iran. According to morphological and molecular characters, the species F. graminearum, F. culmorum, F. avenaceum and F. poae were identified. Among the isolates, F. graminearum was the predominant species with the highest frequency and relative density of 92.9% and 70.9%, respectively. We observed that germination and vigor indices were decreased due to increased Fusarium-infected seeds. Results indicated significant differences among cultivars and seed-borne Fusarium levels. While a higher infection level of Fusarium spp. most commonly occurred in the seed coat, only F. graminearum was observed in embryos. Our study about pathogenicity showed that 77.3% of the Fusarium spp. isolates were not pathogenic and 22.7% isolates of Fusarium spp. were pathogenic or weakly pathogenic. Our results indicated that variability in aggressiveness among isolates of a species and positive correlation may be determined by pathogenicity tests. This is the first time the location of Fusarium spp. in seeds has been identified. It is also the first time that Fusarium-infected seeds in pre-basic seeds wheat fields of Iran have been evaluated.

Fusarium head blight (FHB) is one of the most important diseases that occurs in cereal regions worldwide and causes serious economic damage. This disease can be caused by several Fusarium species with Fusarium graminearum sensu stricto being the most common pathogen isolated from several crops. The aim of this study was to report the occurrence of F. graminearum sensu stricto on rye grains collected from field samples in Argentina and to determine the potential ability to produce deoxynivalenol (DON), nivalenol (NIV) and zearalenone (ZEA). Based on morphological characteristics, the isolate was identified as F. graminearum sensu stricto. To confirm molecularly, portions of the RED and TRI genes were sequenced and showed 99% similarity with the F. graminearum sensu stricto sequences available in the NCBI database. The potential to produce DON, 15-acetyldeoxynivalenol (15-ADON) and ZEA was determined. Moreover, Koch´s postulates were carried out. To our knowledge, this is the first report of F. graminearum sensu stricto associated with rye kernels in Argentina.

The effect of crude extracts of neem (Azadirachta indica) leaf, neem seed and garlic (Allium sativum) at concentrations ranging from 5% to 30% of the material in 100 ml of Potato Dextrose Agar on mycelial growth of Fusarium oxysporum f. sp. lycopersici was assessed. All the extracts inhibited mycellial growth at various levels. Dry neem seed extract gavel 100% inhibition of mycelial growth. Fresh neem leaf extract reduced mycelial growth with increasing concentration while in garlic there were no differences in growth inhibition among the various concentrations used. However garlic extracts decreased sporulation with increasing concentration and cultures grown on extract amended agar plates remained viable.

Potato (Solanum tuberosum L.), an important food crop in the world, is susceptible to many fungal pathogens including Alternaria solani and Fusarium oxysporum causing Fusarium wilt and early blight diseases. Mycoparasitic fungi like Trichoderma encode chitinases, cell wall degrading enzymes, with high antifungal activity against a wide range of phytopathogenic fungi. In this study, a binary vector harboring endochitinase gene of ~1,000 bp was constructed and used to transform potato nodes through Agrobacterium-mediated transformation. Out of several primary transformants, two transgenic potato lines were verified for transgene insertion and integration by Southern blot. In a pot experiment for Fusarium resistance, the transgenic potato lines didn’t show any symptoms of disease, instead they remained healthy post infection. The transgenic potato lines exhibited 1.5 fold higher mRNA expression of endochitinase at 7 days as compared to 0 day post fungus inoculation. It was evident that the mRNA expression decreased over days of inoculation but was still higher than at 0 day and remained stable upto 30 days post inoculation. Similarly, for A. solani infection assay, the mRNA expression of the endochitinase gene was 3 fold higher 7 days post inoculation compared to expression at 0 day. Although the expression decreased by1.2 fold during subsequent days post infection, it remained stable for 30 days, suggesting that protection in transgenic potato plants against fungal pathogens was achieved through an increase in endochitinase transcript.

This paper presents a preliminary report of Fusarium wilt of Roselle in the Nigerian savanna. Soil and plant samples were collected from eight experimental plots where plants showed Roselle wilt symptoms. Samples were analyzed for the presence of nematodes and wilt pathogens. The wilt causative organism Fusarium oxysporum was isolated together with nematodes of different genera. However, nematodes of the genus Helicotylenchus, Scutellonema and Hoplolaimus appeared to occur in higher densities than the others.

Ability of five strains of Trichoderma pseudokoningii (antagonists) to suppress radial growth of Fusarium verticillioides (Sacc.) Nirenberg (= Fusarium moniliforme Sheldon) was examined in vitro These were T. pseudokoningii strai n1 (IMI 380933), strain 2 (IMI 380937), strain 3 (IMI 3809 39), strain 4 (IMI 380940) a nd strain 5 (IMI 380941). Each strain was paired with pathogen by inoculating at opposite ends of 9 cm petri plates using three pairing methods. Gradings were assigned to varied growth inhibition of pathogen by antagonists and analysed using GLM procedure (SAS). Growth suppression of F. verticillioides by all strains of T. pseudokoningii was significantly different (R² = 0.98, p = 0.05) from control in all pairing methods. It differed significantly (p > 0.0003) among the strains in all pairing methods. Growth suppression also differed significantly among (p>0.0001) and within (p > 0.018) pairing methods. Growth suppression was best when antagonists were inoculated before pathogen. Suppression mechanisms include mycoparasitism and competition for space and nutrients. T. pseudokoningii strains 3 and 4 had the best (p = 0.05) growth suppression of F. verticillioides and could be used as biocontrol agents for endophytic F. verticillioides in maize plant. This experiment was conducted in the search for resedent microorganisms that might be capable of checking F. verticillioides within maize plant by competitive exclusion in subsequent experiment.

Highly active antagonistic actinomycete Streptomyces griseoviridis and entomopathogenic fungus Beauveria bassiana were applied to the soil separately and together (in association) in the laboratory experiments. We assessed survival rate, insecticidal and fungistatic activity of these strains. We also tested the influence of synthetic insecticide Regent 25® (fipronil 25g/l) on investigated parameters. Additionally, insecticidal activity of both strains was compared with insecticidal activity of Regent. It was shown that both strains, especially S. griseoviridis, good survived in soil. Population density of S. griseoviridis in the association with B. bassiana increased 2–3 times compared to initial density. Regent considerably reduced population density of S. griseoviridis and B. bassiana. Insecticidal efficiency of S. griseoviridis was comparable with the effect of synthetic incecticide Regent and reached 89.2% and 86.8% respectively. Fungistatic activity towards Fusarium oxysporum showed only S. griseoviridis and it was observed that this activity decreased in time course.

This research was conducted to investigate the natural, quantitative composition of the most common Fusarium species directly in fields of northeastern Poland. The concentration of Fusarium spp. and grain quality traits (yield, 1,000 kernel weight, test weight, grain moisture, ergosterol content, protein content, gluten content and starch content) were compared in four wheat varieties (Mandaryna, Struna, Kandela and Arabella). Obtained results indicated a relation between grain moisture, test weight, ergosterol content, yield and fungi concentration. Protein, starch and gluten content was similar in all wheat varieties. Fusarium culmorum was the most common pathogen in Mandaryna and Struna and F. graminearum in Kandela and Arabella. Fusarium avenaceum and F. poae occurred in low amounts in all wheat varieties except Mandaryna. Fusarium oxysporum was found in comparable concentrations in Struna, Kandela and Arabella. Struna despite medium Fusarium spp. colonization possessed the most desirable grain quality compared to other varieties. We carried out real-time PCR detection of Fusarium spp. which is an efficient, cost effective and time saving method in evaluating the development of fungal diseases which are not visible in standard observations.

Three plant extracts viz. bulbs of Allium sativum L. (Liliaceae), seeds of Annona squamosa L. (Annonaceae) and leaves of Vitex negundo L. (Verbenaceae) were evaluated against cowpea wilt pathogen, Fusarium oxysporum f. sp. ciceris by mycelial dry weight method under laboratory condtions. The mean mycelium dry weights of F. oxysporum of methanol and benzene extracts of A. sativum obtained from 125 g of crused dry plant material (bulbs) were 0.0113 and 0.0174 mg, respectively. This was followed by methanol and petroleum ether extracts of A. squamosa (0.2396 and 0.2381 mg). They effectively controlled mycelial growth of cowpea wilt pathogen, however V. negundo extracts did not cause any significant mycelium growth inhibition when compared to other plant extracts tested. Among the three plant extracts, methanol extracts of A. sativum bulbs could possibly be used for controlling F. oxysporum.

Influence of Fusarium oxysporum f. sp. cubense (E.F. Smith) Snyder and Hansen on 2,4-diacetylphloroglucinol (DAPG) production in the rhizosphere of banana cultivar Rasthali by Pseudomonas fluorescens was investigated. The purified extracts of Pfm strain of P. fluorescens isolated from banana rhizosphere inhibited the growth and spore germination of F. oxysporum f. sp. cubense under laboratory conditions. DAPG extracted from the cultures of the strain was observed as distinct spots in thin layer chromatographic plates at Rf value of 0.88. The extracts of soil inoculated with P. fluorescens and challenge inoculated with F. oxysporum f. sp. cubense eluted at retention time ranges from 20.00 min to 21.30 min. The quantity of DPAG production was less in the extracts of soil inoculated with P. fluorescens and challenge inoculated with F. oxysporum f. sp. cubense as compared to P. fluorescens alone inoculated soil. The talc formulation of Pfm strain also reduced vascular discolouration due to the pathogen in banana plants when inoculated at 15 g/plant.

Stem base health of spring barley cultivated under organic, integrated and conventional systems and fungal communities were studied. A worst plant health status was observed in the organic system. The macroscopic and subsequent mycological analyses revealed the occurrence of Bipolaris sorokiniana and Fusarium spp. The incidence of B. sorokiniana on stem bases was clearly dependent on a farming system, and the highest incidence of this pathogen was observed in the organic system. Also, in that system, Fusarium spp. were isolated more numerously in the beginning of tillering, but in dough stage B. sorokiniana was the most prevalent pathogen, and Fusarium spp. were more numerous in integrated and conventional systems. It is worth to note that organic conditions could be favourable to Gliocladium spp. Because of growing interest in ecology, excluding the use of pesticides and increasing popularity of biological disease control, these antagonistic fungi could be useful in organic systems.

Essential oils from four plants , i.e. geranium, rosa, lemon and mint were tested for their activity in vitro and in vivo against Rhizoctonia solani and Fusarium oxysporum f. sp. phaseoli, the cause of root rot and wilt of beans. In vitro, they were found to have an inhibitory effect against the mycelial growth of R. solani and F. oxysporum f. sp. phaseoli. Complete inhibition in fungal growth was observed at a concentration of 4% of each essential oil and Topsin M at 400 ppm as well. In greenhouse the four essential oils were tested as seed coating and/or foliar spray. Results of seed coating at a concentration of 1% clearly demonstrate a good protection of emerged bean seeds against invasion of R. solani and F. oxysporum f. sp. phaseoli compared with the fungicide treatment. A similar trend was observed in a lower extent when the essential oils were applied as bean seeds coating followed by seedlings foliar spray under field conditions. Obvious yield increase as bean green pods, in all treatments, was significantly higher than in the control.

Although Syrian high-yielding wheat cultivars grown under Mediterranean conditions include acceptable levels of resistance to biotic constraints, little is known about their susceptibility to Fusarium head blight (FHB), a harmful disease of wheat cultivation worldwide. The capacity of 16 fungal isolates of four FHB species to confer the disease on spikes and spikelets of six widely grown old and modern Syrian durum and bread wheat cultivars with known in vitro quantitative resistance to FHB was evaluated. Quantitative traits were visually assessed using spray and point inoculations for determining disease development rates, disease incidence (DI) and disease severity (DS) under controlled conditions. Differences in pathogenicity and susceptibility among wheat cultivars were observed, emphasizing the need for breeders to include aggressive isolates or a mixture of isolates representative of the FHB diversity in their screenings for selection of disease resistant cultivars. Bread wheat cultivars showed lower levels of spike and spikelet damage than durum cultivars regardless of the date of cultivar release. Overall, the six wheat cultivars expressed acceptable resistance levels to initial fungal infection and fungal spread. Quantitative traits showed significant correlation with previous standardized area under disease progress curve (AUDPCstandard) data generated in vitro. Thus, the predictive ability of AUDPCstandard appears to be crucial in assessing pathogenicity and resistance in adult wheat plants under controlled conditions. While in the Mediterranean countries the risk of disease is progressively increasing, the preliminary data in this report adds to our knowledge about four FHB species pathogenicity on a Syrian scale, where the environment is quite similar to some Mediterranean wheat growing areas, and show that Syrian cultivars could be new resistant donors with favorable agronomical characteristics in FHB-wheat breeding programs.

Fusarium crown rot (FCR), caused by Fusarium culmorum (Wm.G.Sm) Sacc., is an important disease of wheat both in Iraq and other regions of wheat production worldwide. Changes in environmental conditions and cultural practices such as crop rotation generate stress on pathogen populations leading to the evolution of new strains that can tolerate more stressful environments. This study aimed to investigate the genetic diversity among isolates of F. culmorum in Iraq. Twenty-nine samples were collected from different regions of wheat cultivation in Iraq to investigate the pathogenicity and genetic diversity of F. culmorum using the repetitive extragenic palindromic (REP-PCR) technique. Among the 29 isolates of F. culmorum examined for pathogenicity, 96% were pathogenic to wheat at the seedling stage. The most aggressive isolate, from Baghdad, was IF 0021 at 0.890 on the FCR severity index. Three primer sets were used to assess the genotypic diversity via REP, ERIC and BOX elements. The amplicon sizes ranged from 200–800 bp for BOX-ERIC2, 110–1100 bp for ERIC-ERIC2 and 200–1300 bp for REP. A total of 410 markers were polymorphic, including 106 for BOX, 175 for ERIC and 129 for the REP. Genetic similarity was calculated by comparing markers according to minimum variance (Squared Euclidean). Clustering analysis generated two major groups, group 1 with two subgroups 1a and 1b with 5 and 12 isolates, respectively, and group 2 with two subgroups 2a and 2b with 3 and 9 isolates, respectively. This is the first study in this field that has been reported in Iraq.