Fungi and oomycetes encompass many pathogens affecting crops worldwide. Their effective control requires screening pathogens across the local and international trade networks along with the monitoring of pathogen inocula in the field. Fundamentals to all of these concerns are their efficient detection, identification, and quantification. The use of molecular markers showed the best promise in the field of plant pathogen diagnostics. However, despite the unquestionable benefits of DNA-based methods, two significant limitations are associated with their use. The first limitation concerns the insufficient level of sensitivity due to the very low and uneven distribution of pathogens in plant material. The second limitation pertains to the inability of widely used diagnostic assays to detect cryptic species. Targeting mtDNA appears to provide a solution to these challenges. Its high copy number in microbial cells makes mtDNA an attractive target for developing highly sensitive assays. In addition, previous studies on different pathogen taxa indicated that mitogenome sequence variation could improve cryptic species delimitation accuracy. This review sheds light on the potential application of mtDNA for pathogen diagnostics. This paper covers a brief description of qPCR and DNA barcoding as two major strategies enabling the diagnostics of plant pathogenic fungi and oomycetes. Both strategies are discussed along with the potential use of mtDNA, including their strengths and weaknesses.

Fusarium head blight (FHB) of cereals is the major head disease negatively affecting grain production worldwide. In 2016 and 2017, serious outbreaks of FHB occurred in wheat crops in Poland. In this study, we characterized the diversity of Fusaria responsible for these epidemics using TaqMan assays. From a panel of 463 field isolates collected from wheat, four Fusarium species were identified. The predominant species were F. graminearum s.s. (81%) and, to a lesser extent, F. avenaceum (15%). The emergence of the 15ADON genotype was found ranging from 83% to 87% of the total trichothecene genotypes isolated in 2016 and 2017, respectively. Our results indicate two dramatic shifts within fungal field populations in Poland. The first shift is associated with the displacement of F. culmorum by F. graminearum s.s. The second shift resulted from a loss of nivalenol genotypes. We suggest that an emerging prevalence of F. graminearum s.s. may be linked to boosted maize production, which has increased substantially over the last decade in Poland. To detect variation within Tri core clusters, we compared sequence data from randomly selected field isolates with a panel of strains from geographically diverse origins. We found that the newly emerged 15ADON genotypes do not exhibit a specific pattern of polymorphism enabling their clear differentiation from the other European strains.

Soybean is an important, high protein source of food and feed. However, like other agricultural grains, soybean may pose a risk to human and animal health due to contamination of the grains with toxigenic Fusaria and associated mycotoxins. In this study, we investigated the diversity of Fusaria on a panel of 104 field isolates obtained from soybean grains during the growing seasons in 2017–2020. The results of species-specific PCR analyses showed that Fusarium avenaceum was the most common (n = 40) species associated with soybean grains in Poland, followed by F. equiseti (n = 22) and F. sporotrichioides (11 isolates). A set of isolates, which was not determined based on PCR analyses, was whole genome sequenced. Multiple sequence analyses using tef-1α, top1, rpb1, rpb2, tub2, pgk, cam and lsu genes showed that most of them belonged to Equiseti clade. Three cryptic species from this clade: F. clavum, F. flagelliforme and FIESC 31 (lacking Latin binomial) were found on soybean for the first time. This is the first report demonstrating the prevalence of Fusaria on soybean grains in Poland.

Legumes are amongst the most promising crops to satisfy the increasing demand for protein-rich food and feed. Today, however, their cultivation in Europe is low, while European agriculture faces a deficit of protein-rich feed, of which the largest part is met by imported soybean. It has been suggested that some legumes can at least partially substitute for soybean in different types of feed. Despite their benefits, legumes may also remain a significant concern to human and animal health, especially regarding grain contamination with Fusaria and their mycotoxins. In this study, we determined the species composition of Fusarium field isolates recovered from diseased grains of various legumes. Our results showed that Fusarium avenaceum was mainly responsible for grain deterioration of common vetch, faba bean, and blue lupine. Besides, we found that F. equiseti also appeared to be a major pathogen of common vetch. This study is the first ever to report common vetch as a host for F. tricinctum, F. equiseti, and F. graminearum sensu stricto. Our results indicate that the composition of toxigenic Fusaria associated with grains of legumes is different than that previously observed in cereal grains.

Suburbanizacja, jako składowa procesu metropolizacji, a jednocześnie jeden z etapów cyklu życia aglomeracji miejskich, dotyczy obecnie prawie wszystkich głównych ośrodków miejskich naszego kraju, stanowiąc podstawowy problem związany z ich rozwojem. Przydatnym narzędziem badania zróżnicowania natężenia suburbanizacji w strefach podmiejskich czy szerzej - na obszarach metropolitalnych - mogą być statystyczne metody klasyfikacji danych, takie jak analiza skupień. Metody te pozwalają na grupowanie jednostek terytorialnych danego obszaru (np. powiatów, gmin, miejscowości statystycznych) we względnie jednorodne klasy pod kątem natężenia zjawisk suburbanizacyjnych. Podstawą takiego grupowania jest podobieństwo pomiędzy poszczególnymi badanymi obiektami (np. gminami) w zakresie wartości zmiennych przyjmowanych za wskaźniki zaawansowania suburbanizacji.