Effect of chemical alternatives to methyl bromide on soil-borne disease incidence and fungal populations in Spanish strawberry nurseries: A long-term study

Impacts of the Ban on the Soil-Applied Fumigant Methyl Bromide

The loss of the soil fumigant methyl bromide (MeBr) and adoption of soil fumigant alternatives has been challenging for farmers, particularly for those crops in which pathogens previously controlled by MeBr have emerged as significant problems, but it has resulted in some unanticipated benefits for the scientific community and the environment. Applauded as one of the most effective environmental agreements to date, the universally accepted Montreal Protocol on Ozone Depleting Substances has had a significant impact on the environment, reducing the release of halogenated compounds from anthropogenic sources enough to mitigate global warming by an estimated 1.1°C by 2021. The funding associated with various MeBr transition programs has increased collaboration across scientific disciplines, commodity groups, industry, and regulatory agencies. Chemical alternatives and improved application strategies, including the development of gas-retentive agricultural films, coupled with sound efficacy data and grower ingenuity have resulted in the sustained production of many of the impacted crops; although there has been some loss of acreage and value, particularly for Florida fumigated crops, for some, value has continued to increase, allowing production to continue. The loss of a single, broad-spectrum tool for pest control has led to a deeper understanding of the specific pest complexes impacting these at-risk crops, as well as the development of new, biologically based management tools for their control while increasing our understanding of the role of the soil microbiome in pest control and crop production.

Description of Gut Mycobiota Composition and Diversity of Caprinae Animals

The fungal community, also known as mycobiota, plays pivotal roles in host nutrition and metabolism and has potential to cause disease. However, knowledge of the gut fungal structure in Caprinae is quite limited. In this study, the composition and diversity of the gut mycobiota of Caprinae animals from different geographical locations (Anhui, Jilin, Guangxi, Shandong, Shanxi, and Tibet) were comprehensively characterized by analyzing the internal transcribed spacer 2 (ITS-2) sequences of the fungal community. The results showed that Ascomycota and Basidiomycota were the dominant phyla, which, respectively, accounted for 90.86 to 95.27% and 2.58 to 7.62% of sequences in samples from each region. Nonetheless, the structure of the gut mycobiota was largely different in Caprinae animals in the different provinces. Therein, Sporormiaceae and Thelebolaceae were the dominant fungal families in the samples from Tibet, whereas their abundance was generally low in other regions. The intestinal diversity of individuals from Guangxi was higher than that in other regions. In addition, there were 114 differential genera among all regions. Finally, the co-occurrence network revealed 285 significant correlations in cross-family pairs in the guts of Caprinae animals, which contained 149 positive and 136 negative relationships, with 96 bacterial and 86 fungal participants at the family level. This study has improved the understanding of the mycobiota of ruminants and provided support for the improvement in animal health and productivity. IMPORTANCE In this study, we elucidated and analyzed the structure of the gut mycobiota of Caprinae animals from different regions. This study revealed differences in the structure of the gut mycobiota among Caprinae animals from different geographical environments. Based on previous findings, correlations between fungal and bacterial communities were analyzed. This study adds to previous research that has expanded the present understanding of the gut microbiome of Caprinae animals.

Dual purpose: Predatory hoverflies pollinate strawberry crops and protect them against the strawberry aphid, Chaetospihon fragaefolii

BACKGROUND

Predatory syrphids are an important functional group due to their potential for providing multiple ecosystem services. Adults feed on nectar and pollen, and can be effective pollinators, while larvae are voracious predators that can reduce aphid pressure. Still, little research has addressed their potential dual function in agroecosystems. In this study, we assessed the potential of two predatory hoverflies, Eupeodes corollae and Sphaerophoria rueppellii, for delivering concurrent pollination and biological control of Chaetospihon fragaefolii in greenhouse strawberries.

RESULTS

Both hoverfly species effectively pollinated strawberry flowers of two different varieties ('Elsanta' and 'Sonsation'), resulting in an increase in high-quality marketable fruits, a reduction of fruit deformities, and higher number of seeds per fruit compared to pollinator-excluded fruits. S. ruepellii had a significantly longer flower handling time than E. corollae, which translated to a more efficient pollination expressed as higher seed numbers per fruit after a single flower visit. By contrast, flowers that were open to multiple visits were more effectively pollinated by E. corollae, suggesting that E. corollae is potentially a better cross-pollinator than S. rueppellii. In addition, both hoverfly species suppressed aphid populations in strawberry (var. 'Sonata'), with S. rueppellii and E. corollae reducing aphid populations by 49% and 62%, respectively.

CONCLUSION

Predatory syrphids can concurrently contribute to pollination and biological control in strawberry in a greenhouse setting. © 2022 Society of Chemical Industry.

The Arbuscular Mycorrhizal Fungus Glomus viscosum Improves the Tolerance to Verticillium Wilt in Artichoke by Modulating the Antioxidant Defense Systems

Verticillium wilt, caused by the fungal pathogen Verticillium dahliae, is the most severe disease that threatens artichoke (Cynara scolymus L.) plants. Arbuscular mycorrhizal fungi (AMF) may represent a useful biological control strategy against this pathogen attack, replacing chemical compounds that, up to now, have been not very effective. In this study, we evaluated the effect of the AMF Glomus viscosum Nicolson in enhancing the plant tolerance towards the pathogen V. dahliae. The role of the ascorbate-glutathione (ASC-GSH) cycle and other antioxidant systems involved in the complex network of the pathogen-fungi-plant interaction have been investigated. The results obtained showed that the AMF G. viscosum is able to enhance the defense antioxidant systems in artichoke plants affected by V. dahliae, alleviating the oxidative stress symptoms. AMF-inoculated plants exhibited significant increases in ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), and superoxide dismutase (SOD) activities, a higher content of ascorbate (ASC) and glutathione (GSH), and a decrease in the levels of lipid peroxidation and hydrogen peroxide (H₂O₂). Hence, G. viscosum may represent an effective strategy for mitigating V. dahliae pathogenicity in artichokes, enhancing the plant defense systems, and improving the nutritional values and benefit to human health.