A European Database of Fusarium graminearum and F. culmorum Trichothecene Genotypes

. Fusarium species, particularly Fusarium graminearum and F culmorum, are the main cause of trichothecene type B contamination in cereals. Data on the distribution of Fusarium trichothecene genotypes in cereals in Europe are scattered in time and space. Furthermore, a common core set of related variables (sampling method, host cultivar, previous crop, etc.) that would allow more effective analysis of factors influencing the spatial and temporal population distribution, is lacking. Consequently, based on the available data, it is difficult to identify factors influencing chemotype distribution and spread at the European level. Here we describe the results of a collaborative integrated work which aims (1) to characterize the trichothecene genotypes of strains from three Fusarium species, collected over the period 2000-2013 and (2) to enhance the standardization of epidemiological data collection. Information on host plant, country of origin, sampling location, year of sampling and previous crop of 1147 F graminearurn, 479 F culmorum, and 3 F cortaderiae strains obtained from 17 European countries was compiled and a map of trichothecene type B genotype distribution was plotted for each species. All information on the strains was collected in a freely accessible and updatable database (www.catalogueeu.luxmcc.lu), which will serve as a starting point for epidemiological analysis of potential spatial and temporal trichothecene genotype shifts in Europe. The analysis of the currently available European dataset showed that in F. grarninearum, the predominant genotype was 15-acetyldeoxynivalenol (15-ADON) (82.9%), followed by 3-acetyldeoxynivalenol (3-ADON) (13.6%), and nivalenol (NIV) (3.5%). In F culmorum, the prevalent genotype was 3-ADON (59.9%), while the NIV genotype accounted for the remaining 40.1%. Both, geographical and temporal patterns of trichothecene genotypes distribution were identified.</p

Analysis of Small RNAs of Barley Genotypes Associated with Resistance to Barley Yellow Dwarf Virus

Barley yellow dwarf virus (BYDV) causes an often-devastating disease of cereals that is most effectively controlled by using plant genotypes that are resistant or tolerant to the virus. New barley lines Vir8:3 and Vir13:8, with pyramided resistance genes against different pathogens and resistance gene Ryd2 against BYDV, are currently being tested. Because microRNAs (miRNAs) are associated with antiviral plant defense, here we compared the miRNA profiles in these lines and in cultivar Wysor (carrying one resistance gene, Ryd2), with and without BYDV infection and after feeding by virus-free aphids, to determine whether the miRNA profile in the resistant variety bear similarities with the newly developed lines. The BYDV titer for each group was also determined and compared to the titer in sensitive cultivar Graciosa. Among 746 miRNAs identified in barley, 66 were known miRNAs, and 680 were novel. The expression of 73 miRNAs differed significantly after BYDV infection, including the strong, specific upregulation of novel miRNA10778 that was conserved across all the barley genotypes. This miRNA belongs to the H box and ACA box (H/ACA) snoR14 family of RNAs (Rf01280) and is associated with pseudourydilation. The expression of 48 miRNAs also differed depending on the barley genotype. The profile of miRNAs expressed in Vir8:3 and Vir13:8 in response to BYDV was similar and differed from that of Wysor. Insights into the expression patterns of miRNAs in response to BYDV in barley provided here will benefit further studies toward understanding the resistance mechanisms and developing novel strategies against virus infections

Methodology of testing wheat resistance to Fusarium head blight under field conditions

This handbook brings new conclusions and recommendations concerning evaluation of resistance to Fusarium head blight. The presented findings are based on experience gained from the tests of disease resistance performed in the period 2002-2015, on results of monitoring of Fusarium pathogens (2011 – 2014), available literature and special experiments. This methodology is mainly aimed at increasing precision of tests of resistance to Fusarium head blight which will favourably impact on resistance breeding

Methodology of testing wheat resistance to brown leaf spot diseases under field conditions

This handbook brings new conclusions and recommendations concerning mainly the field resistance tests - the choice of fungal isolates, design of experiments, inoculum preparation and inoculation technique, as well as evaluation of disease symptoms and tolerance to the disease. Attention was paid to the pathogens Mycosphaerella graminicola anam. Septoria tritici, Pyrenophora tritici – repentis anam. Drechslera tritici-repentis and Phaeosphaeria nodorum anam. Stagonospora nodorum that showed frequent occurrence in the examined territory. The presented findings are based on experience gained from the ring tests of disease resistance performed in the period 2002-2014, available literature and special experiments with Septoria tritici performed within the research project QJ QJ 1210189 This methodology is mainly aimed at increasing precision of tests of resistance to these diseases which will favourably impact on resistance breeding, variety testing, as well as on adequacy of plant protection measures taken in agricultural practice

The Use of Real-Time PCR for the Pathogen Quantification in Breeding Winter Wheat Varieties Resistant to Eyespot

The reaction of twenty-five winter wheat cultivars frequently grown in the Czech Republic to inoculation with Oculimacula yallundae and Oculimacula acuformis was evaluated in small plot trials from 2019 to 2021. The eyespot infection assessment was carried out visually using symptoms on stem bases and quantitative real-time polymerase chain reaction (qPCR). The cultivars were also tested for the presence of the resistance gene Pch1 using the STS marker Xorw1. Statistical differences were found between cultivars and between years. The lowest mean level of eyespot infection (2019&ndash;2021) was visually observed in cultivar Annie, which possessed resistance gene Pch1, and in cultivar Julie. Cultivars Turandot and RGT Sacramento were the most susceptible to eyespot. The method qPCR was able to distinguish two eyespot pathogens. O. yallundae was detected in higher concentrations in inoculated plants compared with O. acuformis. The relationship between the eyespot symptoms and the pathogen&rsquo;s DNA content in plant tissues followed a moderate linear regression only in 2021. The highest eyespot infection rate was in 2020 due to weather conditions suitable for the development of the disease

Methodology of rearing of viruliferous population of aphid Rhopalosiphum padi, as a vector of Barley yellow dwarf virus (BYDV)

The methodology describes innovative procedures of rearing virulent population of Rhopalosiphum padi aphids, as a vector of Barley yellow dwarf virus (BYDV), for artificial infections of cereals. The method is a modification of existing procedure used in our laboratory for this purpose. The advantage of present methodology includes more abundance of viruliferous aphids within shorter period and effective control against aphid predators than the earlier used methodology

Cereal diseases from sowing to harvest (determination and protection options):Methodology for practice

The fungal and virus diseases are still very actual topics due to the high proportion of cereals in crop rotation and large cultivated area. The cereal crops often decimated by fungal diseases like eyespot, powdery mildew, smuts, rusts, Fusarium head blight and brown leaf spot diseases. The virus diseases include Barley yellow dwarf virus – BYDV, Wheat dwarf virus – WDV and Wheat streak mosaic virus – WSMV are also very important due to the epidemic incidence in some years. This methodology summarizes the current knowledge of these fungal and virus diseases, focuses on the description, symptoms, occurrence, field and laboratory diagnostics and possibilities of crop protection against these diseases. Individual diseases are ranked in the order of their occurrence in the agroecosystem. The methodology can serve the farming communities and agronomist as a key to identifying the diseases infecting wheat crop