Colletotrichum species are among the most devastating plant pathogens in a wide range of hosts. Their accurate identification requires a polyphasic approach, including geographical, ecological, morphological, and genetic data. Solanaceous crops are of significant economic importance for Bulgarian agriculture. Colletotrichum-associated diseases pose a serious threat to the yield and quality of production but are still largely unexplored. The aim of this study was to identify and characterize 26 pathogenic Colletotrichum isolates that threaten solanaceous crops based on morphological, pathogenic, and molecular data. DNA barcodes enabled the discrimination of three main taxonomic groups: C. acutatum, C. gloeosporioides, and C. coccodes. Three different species of acutatum complex (C. nymphaeae, C. godetiae, and C. salicis) and C. cigarro of the gloeosporioides complex were associated with fruit anthracnose in peppers and tomatoes. The C. coccodes group was divided in two clades: C. nigrum, isolated predominantly from fruits, and C. coccodes, isolated mainly from roots. Only C. salicis and C. cigarro produced sexual morphs. The species C. godetiae, C. salicis, and C. cigarro have not previously been reported in Bulgaria. Our results enrich the knowledge of the biodiversity and specific features of Colletotrichum species, which are pathogenic to solanaceous hosts, and may serve as a scientific platform for efficient disease control and resistance breeding.

Wheat (Triticum aestivum L.) is a crucial global food crop. The intensive crop farming, monoculture cultivation, and impact of climate change affect the susceptibility of wheat cultivars to biotic stresses, mainly caused by soil fungal pathogens, especially those belonging to the genus Fusarium. This situation threatens yield and grain quality through root and crown rot. While conventional chemical fungicides face resistance issues and environmental concerns, biological alternatives like seed priming with natural metabolites are gaining attention. Polyamines, including putrescine, spermidine, and spermine, are attractive priming agents influencing plant development and abiotic stress responses. Spermine in particular shows potential for in vitro antifungal activity against Fusarium. Optimising spermine concentration for seed priming is crucial to maximising protection against Fusarium infection while ensuring robust plant growth. In this research, we explored the potential of the polyamine spermine as a seed treatment to enhance wheat resilience, aiming to identify a sustainable alternative to synthetic fungicides. Our findings revealed that a six-hour seed soak in spermine solutions ranging from 0.5 to 5 mM did not delay germination or seedling growth. In fact, the 5 mM concentration significantly stimulated root weight and length. In complementary in vitro assays, we evaluated the antifungal activity of spermine (0.5–5 mM) against three Fusarium species. The results demonstrated complete inhibition of Fusarium culmorum growth at 5 mM spermine. A less significant effect on Fusarium graminearum and little to no impact on Fusarium oxysporum were found. The performed analysis revealed that the spermine had a fungistatic effect against the pathogen, retarding the mycelium growth of F. culmorum inoculated on the seed surface. A pot experiment with Bulgarian soft wheat cv. Sadovo-1 was carried out to estimate the effect of seed priming with spermine against infection with isolates of pathogenic fungus F. culmorum on plant growth and disease severity. Our results demonstrated that spermine resulted in a reduced distribution of F. culmorum and improved plant performance, as evidenced by the higher fresh weight and height of plants pre-treated with spermine. This research describes the efficacy of spermine seed priming as a novel strategy for managing Fusarium root and crown rot in wheat.

Legumes contain variable amounts of bioactive substances, including protease inhibitors, which have a protective role against herbivorous insects and bacterial, fungal, and viral pathogens. However, their potential for application in agricultural and medicinal practices requires additional investigation. Bitter vetch (Vicia ervilia (L.) Willd.) is an ancient crop that is now underutilized, and its potential for various applications has recently been reevaluated. In this study, we report the purification, characterization, and bioactive properties of a protease inhibitor against trypsin/chymotrypsin-type proteases (vPI) from bitter vetch seeds. The inhibitor was purified by extraction under acidic conditions, ammonium sulfate fractionation, and size-exclusion chromatography. Its inhibitory specificity, thermostability, pH stability, and antioxidant and antimycotic activity against Alternaria alternata, Alternaria solani, Aspergillus fumigatus, Aspergillus niger, Candida albicans, Fusarium solani, Mucor michei, Penicillium griseofulvum, and Rhizopus oryzae were evaluated. Purified vPI presented superoxide anion scavenging power and antifungal activity in response to all tested strains except M. michei. It had the strongest effect on F.solani and A. solani, and a moderate effect on P. griseofulvum and C. albicans. The treatment of A. alternata, R. oryzae, A. fumigatus, and A. niger demonstrated high efficacy within the initial 24h but declined thereafter. The usefulness and limitations of the vPI application in practice are discussed.

This paper presents new records and noteworthy data on the following taxa in SE Europe and adjacent regions: fungi Calvatia cyathiformis, Gastrosporium simplex, Hypomyces chlorinus, and Schenella pityophila, mosses Buxbaumia viridis, Didymodon de­sertorum, Heterocladium wulfsbergii, Leucobryum glaucum, Microbryum floerkeanum, Sphagnum obtusum, and Ptychostomum schleicheri var. latifolium, dicots Corylus colurna, Galatella linosyris, Menyanthes trifoliata, and Polygonum albanicum, and mono­cots Dactylorhiza saccifera, Epipactis helleborine subsp. distans, Ophrys apifera, and Orchis × hybrida