Identification of Pathogenic Fusarium spp. Responsible for Root Rot of Angelica sinensis and Characterization of their Biological Enemies in Dingxi, China

Root rot is a serious disease in plantations of A. sinensis, severely affecting yield and quality and threatening sustainable production. Fusarium isolates (n=32) were obtained from field samples of root rot tissue, leaves and infected soil. Isolates were identified by comparing the sequences of their internal transcribed spacer (ITS) region and translation elongation factor 1-ɑ (TEF-1ɑ) to sequences of known species in the NCBI-database. These Fusarium isolates include F. tricinctum (43.75%), F. equiseti (31.25%), F. solani (9.37%), F. oxysporum (6.25%), F. acuminatum (6.25%), and F. incarnatum (3.12%). For pathogenicity testing under greenhouse conditions, seven isolates were selected based on a phylogenetic analysis, including four strains of F. tricinctum and one strain each of F. solani, F. oxysporum, and F. acuminatum. The seven isolates were all pathogenic but differed in their ability to infect: the four F. tricinctum strains were capable pathogens causing root rot in A. sinensis at 100% incidence and the highly aggressive. Furthermore, the symptoms of root rot induced by those seven isolates were consistent with typical root rot cases in the field, but their disease severity varied. Observed histopathological preparations of F. tricinctum-infected seedlings and tissue-slides results showed this fungal species can penetrate epidermal cells and colonize the cortical cells where it induces necrosis and severe plasmolysis. Plate confrontation experiments showed that isolated rhizosphere bacteria inhibited the Fusarium pathogens that cause root rot in A. sinensis. Our results provide timely information for informing the use of biocontrol agents for suppression of root rot disease.

An eco-friendly way to protect wheat seeds from phytopathogens

Protecting wheat seed from phytopathogens is a popular topic for plant breeders. The objects requiring close attention and control on wheat are smut infections, pathogens of root rot. And if the pathogens of smut we have learned to fight quite effectively with, then microorganisms that infect underground parts of plants are controlled with less success and many questions in the system of protection against them remain controversial. The issue of reducing the pesticide load on agrocenoses, starting with the protection of seeds, also remains relevant. The article presents the results of field trials of means of protecting spring wheat seeds from root rot in 2019–2020, carried out within the framework of the state assignment at the Kurgan SRIA — branch of FSBSI UrFASRC, according to generally accepted methods. The aim of the research was to assess the biological, economic efficiency of the combined use of a chemical seed dressing agent and a biofungicide based on Bacillus subtilis in protecting wheat from soil-seed infections, to determine the competitiveness of an ecologized method of protecting seeds (reduced consumption rate of a chemical seed dressing agent in combination with biological fungicide). The obtained research results indicate that with a high level of damage to wheat by root rot (Fusarium, B. sorokiniana), the use of seed treatment with the studied preparations ensured the preservation of 10–12% of the yield, more efficiency was noted in the variants with the Oplot 0.5 l/t and the Oplot 0.3 l/t + Nodix Premium 0.3 l/t . The technical effectiveness of fungicides against wheat root rot ranged 44% for Nodix Premium to 85–86% for chemical protection and mixed use. An environmentally friendly method of protecting wheat seeds, which consists in using a 40% lower rate of a chemical dressing agent with a biopesticide, turned out to be competitive.

Biochemical Characterization, Antifungal Activity, and Relative Gene Expression of Two Mentha Essential Oils Controlling Fusarium oxysporum, the Causal Agent of Lycopersicon esculentum Root Rot

Tomato (Lycopersicon esculentum Mill.) is important food in daily human diets. Root rot disease by Fusarium oxysporum caused huge losses in tomato quality and yield annually. The extensive use of synthetic and chemical fungicides has environmental risks and health problems. Recent studies have pointed out the use of medicinal plant essential oils (EOs) and extracts for controlling fungal diseases. In the current research, Mentha spicata and Mentha longifolia EOs were used in different concentrations to control F. oxysporum. Many active compounds are present in these two EOs such as: thymol, adapic acid, menthol and menthyl acetate. These compounds possess antifungal effect through malformation and degradation of the fungal cell wall. The relative expression levels of distinctly upregulated defense-related WRKY genes (WRKY1, WRKY4, WRKY33 and WRKY53) in seedling root were evaluated as a plant-specific transcription factor (TF) group in different response pathways of abiotic stress. Results showed significant expression levels of WRKY, WRKY53, WRKY33, WRKY1 and WRKY4 genes. An upregulation was observed in defense-related genes such as chitinase and defensin in roots by application EOs under pathogen condition. In conclusion, M. spicata and M. longifolia EOs can be used effectively to control this plant pathogen as sustainable and eco-friendly botanical fungicides.

CDC Hickie yellow field pea

CDC Hickie, a yellow cotyledon field pea (Pisum sativum L.) cultivar, was released in 2021 by the Crop Development Centre, University of Saskatchewan for distribution to Select seed growers through the Variety Release Committee of the Saskatchewan Pulse Growers. CDC Hickie has good lodging resistance, medium time to maturity, medium-sized, round seeds, mean seed protein concentration of 24.4%, and good yielding ability. It is resistant to powdery mildew and moderately susceptible to mycosphaerella blight and Fusarium root rot. CDC Hickie is adapted to the field pea growing regions of western Canada.

CDC Lewochko yellow field pea

CDC Lewochko, a yellow cotyledon field pea (Pisum sativum L.) cultivar, was released in 2018 by the Crop Development Centre, University of Saskatchewan for distribution to Select seed growers through the Variety Release Committee of the Saskatchewan Pulse Growers. CDC Lewochko has good lodging resistance, medium time to maturity, medium-sized, round seeds, mean seed protein concentration of 21.0%, and good yielding ability. It is resistant to powdery mildew and moderately susceptible to mycosphaerella blight and Fusarium root rot. CDC Lewochko is adapted to the field pea growing regions of western Canada.

CDC Tollefson yellow field pea

CDC Tollefson, a yellow cotyledon field pea (Pisum sativum L.) cultivar, was released in 2021 by the Crop Development Centre, University of Saskatchewan for distribution to Select seed growers through the Variety Release Committee of the Saskatchewan Pulse Growers. CDC Tollefson has good lodging resistance, medium time to maturity, medium-sized, round seeds, mean seed protein concentration of 23.9%, and good yielding ability. It is resistant to powdery mildew and moderately susceptible to mycosphaerella blight and Fusarium root rot. CDC Tollefson is adapted to the field pea growing regions of western Canada.