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The meso-and micro-scale characteristics of an early spring convective weather event in southwest of Hubei on February 14, 2020 is analyzed comprehensively by using multi-source detection data such as Doppler weather radar, wind profile radar, micro rain radar, two-dimensional video disdrometer and three-dimensional lightning monitoring network, and then the application of the classified severe convective weather identification and warning algorithm is discussed. The results show that: (1) Because of the blocking effect of the mountains in southwest of Hubei, the cold front moves southward slowly in the north of Yichang, and an unstable stratification of upper dry and lower wet, induced by the intersection of the low trough of North China, the warm shear line in the north of the 850 hPa vortex and the cold air infiltrating in front of the cold front, forms in southwest of Hubei. Due to the combination of the warm and humid air of the mid- and low-level southwesterly flow transported along the lower frontal zone, the 850 hPa low level shear line, the surface cold front and the warm inverted trough, the convection is triggered and intensified, and the strong hail occurs at the intersection of the cold front and the warm inverted trough. (2) The wind profile radar data indicate that the southwest of Hubei is located in the warm inverted trough in front of the surface cold front. The continuous enhancement of the middle-upper level southwesterly jet and the incessant infiltration of cold air in front of the cold front jointly stimulate the occurrence and development of strong convection. (3) Disdrometer results illustrate that the raindrop pattern captured the accompanying precipitation process, with the particle diameter mostly within 1 mm and the maximum diameter close to 6 mm. (4) According to the characteristics of raindrop vertical distribution detected by the micro rain radar, due to the low environmental humidity in the early stage of precipitation, remarkable evaporation is existing; but in heavy precipitation period, the effect of coalescence and growth of raindrops near the ground is obvious. (5) The lightning frequency obtained by three-dimensional lightning monitoring network is positively correlated with the intensity variation of hailstorms, and the initial ground flash of two hailstorms is about 30 min and 33 min in advance of hailstone falling, respectively. (6) Doppler radar detected typical hail echo characteristics such as bounded weak echo area and hook-like echo, while the existence of mesocyclone, middle radial convergence and upper divergence area indicates that strong updraft is maintained in convective clouds, which is conducive to the generation and growth of hailstones.

Arbuscularmycorrhizal fungi (AMF) are a class of beneficial microorganisms that are widely distributed in soil ecosystems and can form symbionts with 80% of terrestrial higher plants, and improve the nutritional status of plants. The use of AMF as a biocontrol method to antagonize soil-borne pathogens has received increasing interest from phytopathologists and ecologists. In this paper, the mechanisms of resistance to diseases induced by AMF and the application of AMF to plant fungal, bacterial, and nematode diseases have been summarized. This study aimed to enhance the potential use of AMF as a biological control method to prevent plant diseases in the future. Root morphological alteration characteristics were explained, including the influence of AMF on root structure, function, and the regulation of AMF via secondary metabolites. AMF can improve the rhizosphere environment by influencing the physical and chemical proprieties of soil, enhancing the growth of other beneficial microorganisms, and by competing with pathogenic microorganisms. Two microorganism types may compete for the same invasive sites in root systems and regulate nutrition distribution. AMF can induce the host plant to form defense systems, including improving phytohormone concentrations, inducing signal substrate production, gene expression regulation, and enhancing protein production.

Newcastle disease (ND) is a highly contagious viral disease that constantly threatens poultry production. The velogenic (highly virulent) form of ND inflicts the most damage and can lead to 100% mortality in unvaccinated village chicken flocks. This study sought to characterize responses of local chickens in Ghana after challenging them with lentogenic and velogenic Newcastle disease virus (NDV) strains. At 4 wk of age, chicks were challenged with lentogenic NDV. Traits measured were pre- and post-lentogenic infection growth rates (GR), viral load at 2 and 6 d post-lentogenic infection (DPI), viral clearance rate and antibody levels at 10 DPI. Subsequently, the chickens were naturally exposed to velogenic NDV (vNDV) after anti-NDV antibody titers had waned to levels ≤1:1,700. Body weights and blood samples were again collected for analysis. Finally, chickens were euthanized and lesion scores (LS) across tissues were recorded. Post-velogenic exposure GR; antibody levels at 21 and 34 days post-velogenic exposure (DPE); LS for trachea, proventriculus, intestines, and cecal tonsils; and average LS across tissues were measured. Variance components and heritabilities were estimated for all traits using univariate animal models. Mean pre- and post-lentogenic NDV infection GRs were 6.26 g/day and 7.93 g/day, respectively, but mean post-velogenic NDV exposure GR was -1.96 g/day. Mean lesion scores ranged from 0.52 (trachea) to 1.33 (intestine), with males having significantly higher (P < 0.05) lesion scores compared to females. Heritability estimates for the lentogenic NDV trial traits ranged from moderate (0.23) to high (0.55) whereas those for the vNDV natural exposure trial were very low (≤ 0.08). Therefore, in contrast to the vNDV exposure trial, differences in the traits measured in the lentogenic challenge were more affected by genetics and thus selection for these traits may be more feasible compared to those following vNDV exposure. Our results can form the basis for identifying local chickens with improved resilience in the face of NDV infection for selective breeding to improve productivity., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Newcastle disease (ND) is a global threat to domestic poultry, especially in rural areas of Africa and Asia, where the loss of entire backyard local chicken flocks often threatens household food security and income. To investigate the genetics of Ghanaian local chicken ecotypes to Newcastle disease virus (NDV), in this study, three popular Ghanaian chicken ecotypes (regional populations) were challenged with a lentogenic NDV strain at 28 days of age. This study was conducted in parallel with a similar study that used three popular Tanzanian local chicken ecotypes and after two companion studies in the United States, using Hy-line Brown commercial laying birds. In addition to growth rate, NDV response traits were measured following infection, including anti-NDV antibody levels [pre-infection and 10 days post-infection (dpi)], and viral load (2 and 6 dpi). Genetic parameters were estimated, and two genome-wide association study analysis methods were used on data from 1,440 Ghanaian chickens that were genotyped on a chicken 600K Single Nucleotide Polymorphism (SNP) chip. Both Ghana and Tanzania NDV challenge studies revealed moderate to high (0.18 - 0.55) estimates of heritability for all traits, except viral clearance where the heritability estimate was not different from zero for the Tanzanian ecotypes. For the Ghana study, 12 quantitative trait loci (QTL) for growth and/or response to NDV from single-SNP analyses and 20 genomic regions that explained more than 1% of genetic variance using the Bayes B method were identified. Seven of these windows were also identified as having at least one significant SNP in the single SNP analyses for growth rate, anti-NDV antibody levels, and viral load at 2 and 6 dpi. An important gene for growth during stress, CHORDC1 associated with post-infection growth rate was identified as a positional candidate gene, as well as other immune related genes, including VAV2, IL12B, DUSP1, and IL17B. The QTL identified in the Ghana study did not overlap with those identified in the Tanzania study. However, both studies revealed QTL with genes vital for growth and immune response during NDV challenge. The Tanzania parallel study revealed an overlapping QTL on chromosome 24 for viral load at 6 dpi with the US NDV study in which birds were challenged with NDV under heat stress. This QTL region includes genes related to immune response, including TIRAP, ETS1, and KIRREL3. The moderate to high estimates of heritability and the identified QTL suggest that host response to NDV of local African chicken ecotypes can be improved through selective breeding to enhance increased NDV resistance and vaccine efficacy., (Copyright © 2020 Walugembe, Amuzu-Aweh, Botchway, Naazie, Aning, Wang, Saelao, Kelly, Gallardo, Zhou, Lamont, Kayang and Dekkers.)

The implementation of strategies to detect, prevent, and control highly pathogenic avian influenza (HPAI) in developing countries presents several challenges, one of which is the presence of other diseases in poultry populations. Training workshops in developing countries using the Avian Flu School have revealed that in areas with heavy Newcastle disease burdens, smallholder poultry keepers do not recognize HPAI as an immediate threat. We have developed a strategy to address the more proximal needs and priorities of communities with free-ranging poultry flocks as a means to create value in poultry, and thus to improve disease detection and prevention overall. To this end, we have created the Poultry Health and Well-Being for Development project, which trains graduate veterinarians and paraprofessionals in poultry disease diagnosis, control, and treatment. These trainees then serve their local communities to improve poultry health and to implement disease detection and management programs.