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Four ergot species (Claviceps ripicola, C. quebecensis, C. perihumidiphila, and C. occidentalis) were recognized based on analyses of DNA sequences from multiple loci, including two housekeeping genes, RNA polymerase II second largest subunit (RPB2), and translation elongation factor 1-α (TEF1-α), and a single-copy ergot alkaloid synthesis gene (easE) encoding chanoclavine I synthase oxidoreductase. Morphological features, ergot alkaloid production, and pathogenicity on five common cereal crops of each species were evaluated and presented in taxonomic descriptions. A synoptic key was also provided for identification. [ABSTRACT FROM AUTHOR]

Common reed Phragmites australis (Cav.) Trin. ex Steud. is one of the most widely distributed angiosperms with important ecological functions. In recent decades, it has been affected by a severe decline known as reed die-back syndrome (RDBS), the causal factors of which are still under investigation. Among the biotic factors that influence the dynamic of the reed population, the role of microorganisms is still poorly understood. During surveys carried out on P. australis populations in Central Italy, Claviceps-like sclerotia were detected: is Claviceps infection related to P. australis sexual reproduction and seed production? Could Claviceps infection be involved in the RDBS? These are the questions that we address. We characterized the sclerotia at the morphological, molecular, and chemical level and we demonstrated that they belong to Claviceps arundinis Pažoutová & M. Kolařík. To our knowledge, this is the first report of C. arundinis on P. australis in Italy. Furthermore, the association of C. arundinis with RDBS was evaluated considering a set of macromorphological traits generally related to RDBS, such as P. australis clumping habit, culm height and diameter. No correlation was seen between the occurrence of C. arundinis and the declining status of reed populations. [ABSTRACT FROM AUTHOR]

Ergot alkaloids (EA) are toxins produced mainly by Claviceps fungi and are considered as one of the most important groups of mycotoxins. Rapid and reliable detection techniques are urgently required by producers, importers and market regulators. As a promising alternative to conventional wet chemistry, infrared (IR)-based techniques are non-destructive, rapid and cost-effective. However, very limited studies on the qualitative or quantitative analysis of ergot or EA in food or feed based on IR vibrational spectroscopy have been reported so far. Being a secondary technique, the accuracy of IR method heavily depends on the robustness of chemometrics models. This paper aims to offer a brief overview of the EA issue in food and feed, conventional detection methods, theoretical principles of IR-based techniques and commonly used chemometrics for spectral data processing. In addition, the current application status of IR spectroscopy in ergot research is also considered. [ABSTRACT FROM AUTHOR]

Five methods of harvesting pure secondary conidia were attempted, but only one was successful. The only successful method involved moving air across the surface of water agar plates or moist soil on which secondary sporulation was occurring at 0.2 - 3 m/s. Among the inoculation techniques, brushing the secondary conidia on to the wet stigma gave maximum ergot infection (80%) followed by brushing the secondary conidia on to the dry stigma (77%). Conidia of Claviceps africana produced up to seven generations of sibling conidia. The length and width of secondary conidia showed a reduction in size from 10.92 - 10.13 µm and 5.49 - 5.13 µm, respectively, across generations. However no definite trend in decline in size of secondary conidia was evident. The optimum temperature range for germination of secondary conidia of Australian isolates of C. africana is between 14.6 and 20°C. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to summarize the most relevant and recent information available on ergot alkaloids. This includes information about their occurrence, toxicity, chemistry, statutory limits, and their significance in feed and food. Recently, in 2005, the European Food Safety Authority (EFSA) concluded that validated analytical methods for the quantification of ergot alkaloids in feed materials are needed. For that reason, the major focus of the present paper is to report on the latest developments for the determination of major ergot alkaloids and their epimers in cereals and cereal-derived products. Information about the stability and the availability of calibrants, sampling issues, extraction and clean-up strategies, and a variety of final separation and detection techniques is provided. The recently developed liquid chromatography-tandem mass spectrometric methods (LC-MS/MS) for the simultaneous quantification and identification of ergot alkaloids are given special consideration. [ABSTRACT FROM AUTHOR]

Symptoms of ergot on yellow nut sedge, germination of sclerotia of the causal organism, Claviceps cyperi, and morphology of fresh specimens of the pathogen are described for the first time. The initial symptom of infection was a black sooty layer on inflorescences of infected plants due to colonization of the ergot honeydew by Cladosporium cladosporioides. Sclerotia of C. cyperi started to develop in March and April and could be discerned as small protuberances on inflorescences in the place of seed. Mature sclerotia were purplish-black. They generally remained viable for less than a year and germinated without prior cold treatment, although exposure for 21 d to 5 C before incubation significantly increased the germination rate. Under moist conditions at 24 C in the laboratory, germination commenced within 4-8 wk. Stromata took about 12 d to mature. Mature capitula were distinctly lobulate with a perithecium embedded in each lobe and a collar-like appendage around the base. Although dimensions of sclerotia, stipes, capitula, asci and ascospores were larger than in the original description, the general morphology supports treatment of C. cyperi as a distinct species. [ABSTRACT FROM AUTHOR]

Extensive on-farm disease surveys were conducted from August 1999 until March 2001 in four sorghum-growing states of the Indian Deccan plateau. A total of 965 fields were surveyed covering 228 fields in Andhra Pradesh (AP), 406 in Karnataka (KAR), 290 in Maharashtra (MH) and 41 in Tamil Nadu (TN). Among 14 foliar diseases observed, maize stripe virus (MStV), a tenuivirus transmitted by the delphacid plant hopper (Peregrinus maidis), and among five panicle diseases, ergot or sugary disease (Claviceps sorghi and C. africana) were the most destructive diseases. MStV was prevalent in 28.4% and ergot in 13.4% of the fields surveyed in two years across four states. Yet, the mean incidence of MStV in AP was 6% with 85% mean severity. The values in KAR were 12% incidence and 83% severity, in MH 5% and 67%, and in TN 12% and 76%, respectively. The mean incidence of ergot in AP was 34% with 67% mean severity. The values in KAR were 41% and 79%, in MH, 30% and 67%, and in TN 100% and 100%, respectively. Variation in frequency of occurrence of MStV was observed between 1999 and 2001. Variations in frequency could be due to weather factors, vector survival, cropping pattern, and host specificity. The frequency of ergot also was varying among years, locations, seasons and cultivars. An ergot epidemic was observed during the 1999 rainy season in Maachinenipalli village (16°35′N; 78°3′E), Andhra Pradesh. In September 2000, the disease had spread to 13 neighboring administrative zones damaging about 130,000 ha. This paper elucidates the distribution of diseases observed between 1999 and 2001 but does not imply that the diseases are restricted necessarily to a particular zone or location. [ABSTRACT FROM AUTHOR]

The article focuses on the studies of the ergot fungus Claviceps cynodontis on Cynodon dactylon (C. dactylon). The fungal isolates collected from ergotized C. dactylon in Mexico and Texas with an African isolate of Claviceps cynodontis were compared. It uses a conodial morphology, rDNA sequence, and random amplified polymorphic DNA in identifying the ergot on C. dactylon. It shows that the rDNA sequences obtained from isolates from Africa, Mexico, and Texas were identical.

The potential of corn earworm moths Helicoverpa zea, an important pest of sorghum in Texas, as a passive vector of sorghum ergot, Claviceps africana was assessed. Laboratory-reared (females and males) and field-moths trapped in sex pheromone traps were confined in screen cages with potted male-sterile sorghum line AT×623 that had been artificially infected with sorghum ergot and was producing massive amounts of honeydew that contained spores of the fungus. In the cages, moths were observed feeding on the honeydew. When laboratory-reared moths contaminated with C. africana spores were released for 12 or 48 h in cages containing healthy greenhouse- or field-grown male-sterile sorghum plants at anthesis, the levels of ergot severities on the panicles ranged from 0.5-90%, per panicle. The levels of ergot infection on greenhouse- and field-grown AT×623 exposed to ergot contaminated fieldtrapped males for 48 h ranged from 0-81.7%. Mean external contamination of laboratory-reared and field-trapped moths placed in a soapy wash was 1.4 × 10[sup 5] and 4.7 × 10[sup 4] conidia/ml, respectively. This study demonstrated that contaminated adult corn earworm could transmit the sorghum ergot from diseased to healthy panicles when environmental conditions are favorable for infection. Thus, migrating moths and other highly mobile pest species have the potential to transport C. africana over relatively large distances. [ABSTRACT FROM AUTHOR]