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Rapid and reliable detection of Monilinia latent infections is needed to prevent and control dispersion of Monilinia spp. in infected localities and non-infected countries. A fast multiplex quantitative real-time PCR method (qPCR) for the detection and identification of Monilinia spp. latent infections in blossoms and fruit of nectarine trees (Prunus persica var. nucipersica) was tested in an inter-laboratory trial. The test performance study involving five laboratories was conducted to validate the sensitivity and specificity of several real-time PCR platforms for the detection of low amounts of Monilinia DNA (latent infections), using a common protocol, and to identify possible difficulties when these tests were implemented by diagnostic laboratories or national reference centres. The method has two hydrolysis probes distinguishing between Monilinia fructicola and M. fructigena/M. laxa. Validation included test performance accuracy, analytical specificity and sensitivity, repeatability, and reproducibility, as defined by standard PM7/98 of the European Plant Protection Organization (EPPO). All qPCR platforms detected Monilinia latent infections and mycelium samples with both hydrolysis probes, and healthy flowers and fruit samples gave negative results. The method specificity was consistent between different laboratories, despite different equipment used, and there were no laboratories with z-scores in the unacceptable region. Monilinia fructicola latent infection samples were correctly detected by all laboratories, but some M. laxa samples were cross-detected as if they were M. fructicola. Monilinia laxa cross-detection could be compensated by including the allelic discrimination step in qPCR runs, which permitted differentiating between M. fructicola and M. laxa samples. The inter-laboratory comparison demonstrated the robustness of the developed method and confirmed in-house validation data. This method could be used to detect latent infections of Monilinia in asymptomatic nectarine fruit and flowers. © 2017 Author(s).

Coniothyrium-like fungi are common wood and soil inhabitants and hyperparasites on other fungi. They belong to different fungal genera within the Pleosporales. Several isolates were obtained on wood of different Prunus species (plum, peach and nectarine) from South Africa, on Actinidia species from Italy and on Laurus nobilis from Turkey. Morphological and cultural characteristics as well as DNA sequence data (5.8S nrDNA, ITS1, ITS2, partial SSU nrDNA) were used to characterise them. The isolates belonged to three species of the recently established genus Paraconiothyrium. This is the first report of Paraconiothyrium brasiliense on Prunus spp. from South Africa. Two new species are described, namely Paraconiothyrium variabile sp. nov. on Prunus persica and Prunus salicina from South Africa, on Actinidia spp. from Italy and on Laurus nobilis from Turkey, and Paraconiothyrium africanum sp. nov. on Prunus persica from South Africa. Although other known species of Paraconiothyrium commonly produce aseptate conidia, those of P. africanum and P. hawaiiense comb. nov. are predominantly two-celled.

Tilletia indica, the fungus that causes Karnal bunt of wheat, is listed as a I/AI quarantine pest for the European Union (EU) (Anon., 2000a). This means that it is considered absent from the EU, is potentially damaging and so its entry into the EU is banned. This listing was the result of a Pest Risk Analysis (PRA) (Sansford, 1996, 1998), which considered the potential for the pathogen to enter, establish and cause unacceptable impacts in the UK/EU following the first reports of the disease in the USA in 1996 (Ykema et al., 1996). This PRA was updated in 2004 (Sansford, 2004) and recently fully revised (Sansford et al., 2006) for the EU. This new EU-PRA continues to support the view that T. indica has the potential to enter, establish and cause unacceptable economic impacts throughout much of the wheat-growing area of the EU. Two recent papers (Jones, 2007a,b) have challenged these tenets and the new EU-PRA. In this letter, we summarise the work of a 4-year collaborative study and address the key points made by Jones (2007a,b) and refute his conclusions, particularly regarding (i) past opportunities for entry to Europe; (ii) the climatic requirements for the completion of the lifecycle of T. indica, leading to the disease Karnal bunt; (iii) inoculum thresholds; (iv) the potential economic damage caused by the disease in Europe; and (v) the cost of control. The full findings of the study can be accessed online (http://karnalpublic.pestrisk.net/) together with published accounts of teliospore survival and germination in Europe (Inman et al., 2008) and susceptibility of European wheat cultivars to T. indica (Riccioni et al., 2008).