Invasive weeds of the Asteraceae family are widespread in the world. Arbuscular mycorrhiza (AM) is one of the main factors contributing to the successful distribution of these species that is most clearly manifested in the subfamily Asteroideae. The benefits of plant-AMF symbiosis are most significant under unfavorable biotic and abiotic conditions. The specificity of the relationship between arbuscular mycorrhizal fungi (AMF) communities and plants and is determined at the presymbiotic stage. The AMF colonization level is higher in invasive species than in native ones, but AMF communities associated with Asteraceae invasive species are less diverse. AMF communities of Asteraceae invaders often include fewer common species (e.g., species belonging to Diversisporales). Invaders also reduce native AMF species richness in new areas. Arbuscular mycorrhizal fungi can form mycorrhizal networks that allow the redistribution of nutrients in plant communities. The most significant influence of AMF associated with invasive Asteraceae plants is seen in the formation of soil and rhizosphere microbiota, including the suppression of beneficial soil bacteria and fungi. This review could be useful in the development of practical recommendations for the use of AMF-based fertilizers.
The search for stress-tolerant producer strains is a key factor in the development of biological mycoherbicides. The aim of the study was to assess the herbicidal potential of phoma-like fungi. Morphological and physiological features of two Antarctic psychrotolerant strains 20-A7-1.M19 and 20-A7-1.M29 were studied. Multilocus sequence analysis was used to identify these strains. They happened to belong to Phoma herbarum Westend. The psychrotolerant properties of these strains were suggested not only by ecology, but also by their capability to grow in a wide temperature range from 5 °C to 35 °C, being resistant to high insolation, UV radiation, aridity, and other extreme conditions. It was shown that treatment with their cell-free cultural fugate, crude mycelium extract, and culture liquid significantly reduced the seed germination of troublesome weeds such as dandelion and goldenrod. Cell-free cultural fugate and culture liquid also led to the formation of chlorosis and necrotic spots on leaves. Thus, psychrotolerant strains P. herbarum 20-A7-1.M19 and 20-A7-1.M29 demonstrate high biotechnological potential. Our next step is to determine the structures of biologically active substances and to increase their biosynthesis, as well as the development of biological and biorational mycoherbicides. New mycoherbicides can reduce the chemical load on agroecosystems and increase the effectiveness of applied chemicals.