Symptoms of clover rot caused by Sclerotinia trifoliorum or S. sclerotiorum are identical, making differentiation and identification of the causal species difficult and time consuming. Polymerase chain reaction (PCR) amplification and nucleotide sequencing were used to examine 40 isolates of S. trifoliorum (29 from Poland, 11 from the United States) and 55 isolates of S. sclerotiorum (26 from Poland, 29 from the United States). We determined that amplification of the β-tubulin and calmodulin genes with TU1/TU2/TU3 and SscadF1/SscadR1 PCR primers and the presence of introns and single-nucleotide polymorphisms (SNP) within the ribosomal DNA (rDNA) as detected with NS1/NS8 and internal transcribed spacer (ITS)1/ITS4 PCR primers are effective for rapidly and accurately differentiating between the two species of Sclerotinia. In addition, our research revealed a lack of intraspecies variation within S. sclerotiorum isolates from the United States and Poland using these same molecular markers. We detected a relatively high degree of intraspecies variability among isolates of S. trifoliorum from the United States and Poland using the presence of introns and SNP within the rDNA. SNP and nuclear small-subunit rDNA analyses revealed distinct groups of S. trifoliorum among the isolates used in this study. The results of this study provide useful information for clover breeders and pathologists looking to develop clover varieties with durable resistance.

A growing interest in soybean cultivation in Poland has been observed in the recent years, however it faces a lot of difficulties resulting from a poorly understood effectiveness of plant nitrogen fertilization and from the introduction of Bradyrhizobium japonicum to the environment. The aim of the study was to evaluate the consistency of response of two soybean cultivars to three different rates of mineral N fertilization and two seed inoculation treatments with B. japonicum in field conditions over four years regardless of previous B. japonicum presence in the soil. A highly-diversified-over-years rainfall and temperature in the growing season do not allow for a definite statement of the differences resulting from seed inoculation and mineral N fertilization applied separately or jointly in soybean. A high sensitivity of the nodulation process to rainfall deficits was noted, which resulted in a decreased amount of B. japonicum DNA measured in qPCR and dry matter of nodules. ‘Annushka’ demonstrated a higher yield of seeds and protein, higher plants and the 1st pod setting. ‘Aldana’, due to a significant decrease in plant density, produced a higher number of pods, seeds per pod and the 1000 seed weight per plant. Both cultivars responded with an increase in the seed yield after seed inoculation with HiStick, also with an application of 30 and 60 kg N, as well as with Nitragina with 60 kg N.

Biscogniauxia nummularia (Bull.) Kuntze is a fungus which induces strip-cankers on beech, commonly referred to as charcoal canker. The symptoms of infection are visible on the host tree’s bark as elongated, blackish bark lesions on the trunk and branches. Recent years have shown that, due to climate change causing local epidemics, the species is increasing its economic impact in Mediterranean regions. Until recently, B. nummularia was considered rare and uncommon in central Europe. However, in the last few years it has been noticed more often, mostly in coniferous trees, which are out of B. nummularia’s host range. A similar situation has been observed with the closely related species Biscogniauxia mediterranea (De Not.) Kuntze, which prior to 2017 had not been observed in central Europe at all. This study shows the genetic diversity of mid-European strains of Biscogniauxia spp. (based on the ITS, TEF1, TUB2 and ACT regions) and, as the first in Europe, presents a molecular investigation of this species isolated from coniferous trees. It is also the first attempt at estimating the potential impact of this pathogenic fungus on European forestry management in the close future.

The internal transcribed spacer (ITS) region is regarded as a formal fungal primary barcode with a high probability of the correct identification for a broad group of fungi. ITS sequences have been widely used to determine many fungal species and analysis of rDNA ITS is still one of the most popular tools used in mycology. However, this region is not equally variable in all groups of fungi; therefore, identification may be problematic and result in ambiguous data, especially in some species-rich genera of Ascomycota. For these reasons, identification based on rDNA ITS is usually complemented by morphological observations and analysis of additional genes. Reliable species identification of Ascomycota members is essential in diagnosing plant diseases, verifying air quality and the effectiveness of agronomic practices, or analyzing relationships between microorganisms. Therefore, the present study aimed to verify, using specific examples, the extent to which ITS sequence analysis is useful in species identification of pathogens and saprobionts from Ascomycota and demonstrate problems related to such identification in practice. We analyzed 105 ITS sequences of isolates originating from air and plant material. Basic local alignment search tool (BLASTn) significantly contributed to the reliable species identification of nearly 80% of isolates such as Arthrinium arundinis, Beauveria bassiana, Boeremia exigua, Cladosporium cladosporioides, Epicoccum nigrum, Nigrospora oryzae, Sclerotinia sclerotiorum, or Sordaria fimicola and members of the genera Alternaria and Trichoderma. However, for most isolates, additional morphological observations, information regarding the isolate origin and, where possible, a PCR with species-specific primers were helpful and complementary. Using our practical approach, we determined that ITS-based species identification and comparative analysis with GenBank sequences significantly helps identifying Ascomycota members. However, in many cases, this should be regarded as suggestive of a taxon because the data usually require the use of additional tools to verify the results of such analysis.