Rapid Detection of Airborne Inocula of Grapevine Mildews Using PCR and LAMP Assay

Grapes powdery mildew and downy mildew caused by Erysiphe necator and Plasmopara viticola respectively are the most devastating diseases worldwide resulting in significant loss of yield and quality. Epidemics of grapevine mildews are caused by airborne inocula such as conidia and sporangia. Rapid detection of airborne inocula will help to face up timely management strategies under field conditions. The aim of the current study was to design a suction spore trap to trap the airborne mildew inocula and their early detection by molecular methods of PCR and LAMP assay. A total of twelve airborne inocula samples were collected the weekly intervals from 3 to 14 standard weeks of 2021 during the cropping season. The presence of airborne inocula of E. necator was detected on standard weeks 3,6,10 and 13 through PCR assay which yielded an amplicon of 470 bp. Similarly, airborne inocula of P.viticola were detected on standard week 6 only through PCR which yielded an amplicon of 520 bp. A rapid, highly specific , sensitive Loop mediated isothermal amplification (LAMP) assay was performed to detect the E. necator and P. viticola using six sets of LAMP primers constructed by targeting rDNA region of ITS and the 5S rRNA and CesA4 a gene, respectively. LAMP assay efficiently detected the presence of airborne inocula of E.necator in most of the samples collected from standard week 3 – 14 except 7, 8, and 9. However, the presence of airborne inocula of P.viticola from standard week 3 – 14 was confirmed by LAMP assay. The LAMP assay is absolutely the best in identifying airborne inocula of grapevine mildews compared to PCR and phenotypic microscopic observation.

550Short-term exposure to grass pollen is associated with lower lung function and increased airway inflammation

Background The association between grass pollen exposure and lung function changes and airway inflammation is limited. We investigated these associations in a community-based sample, and whether any such associations were modified by current asthma, current hay fever, pollen sensitization and age. Methods Cross-sectional analyses of data from the Melbourne Atopy Cohort Study (MACS) participants (n = 936). Lung function was assessed using spirometry. Airway inflammation was assessed by fractional exhaled nitric oxide (FeNO), and exhaled breath condensate pH and nitrogen oxides (NOx). Daily pollen counts were collected using a volumetric spore trap. The associations were examined by linear regression. Results Higher ambient levels of grass pollen 2 days before (lag 2) were associated with lower mid-forced expiratory flow (FEF25-75%) and FEV1/FVC ratio (Coef. [95% CI] = -119 [-226, -11] mL/s and -1.0 [-3.0, -0.03] %, respectively) and also 3 days before (lag 3). Increased levels of grass pollen a day before (lag 1) was associated with increased FeNO (4.35 [-0.1, 8.7] ppb) and also at lag 2. Adverse associations between pollen and multiple outcomes were greater in adults with current asthma, hay fever and pollen sensitization. Conclusions Grass pollen exposure was associated with eosinophilic airway inflammation 1-2 days after exposure and airway obstruction 2-3 days after exposure. Key messages There is a more delayed effect on lung function compared to airway inflammation. Adults with current asthma, hay fever and grass pollen sensitisation are especially vulnerable.

The Relationship between Metrological Parameters and Total Airborne Pollen Concentration in Atmosphere of Khartoum City During 2018

This study is aimed to find out the effect and relationship between metrological parameters and total airborne pollen concentration in atmosphere in Khartoum city (Sudan). For that purpose, one-year data during 2018 of Total Airborne Pollen Concentration (TAPC) and meteorological parameters is utilized. Pollen concentration in the atmosphere was measured using Non-volumetric air sampler (Vertical cylinder spore trap). The descriptive statistic of TAPC and metrological parameters were presented. The result showed TAPC in 2018 reached to their maximum in August (37.5/m³), and the minimum in June (14/ m³). Analysis of the relationship between TAPC and meteorological parameters showed that variations in the pollen concentrations were mainly affected by maximum temperature. In addition, there were substantial differences in these relationships in different seasons. In Autumn, they were affected by the rain falls, maximum temperature and relative humidity; in summer, they were affected by maximum temperature; and in winter, they were affected by maximum temperature and relative humidity. Temperature, rain falls and relative humidity promote plant growth and blooming. As well as the results show wind direction was significant on seasonally TAPC especially in Autumn. The results found significant effects between the meteorological on TAPC, were it is showed 72 % are affecting on TAPC refer to meteorological parameters and 28 % refer to another factors.

Monitoring spore dispersal and early infections of Diplocarpon coronariae causing apple blotch using selected spore traps and a new qPCR method

Apple blotch (AB) is a major disease of apples in Asia and recently also emerging in Europe and the USA. It is caused by the fungus Diplocarpon coronariae (Dc) (formerly: Marssonina coronaria; teleomorph: Diplocarpon mali) and leads to severe defoliation of apple trees in late summer and thus to reduced yield and fruit quality. To develop effective crop protection strategies, a sound knowledge of the pathogen's biology is crucial. However, especially data on the early phase of disease development is scarce, and no data on spore dispersal for Europe is available. In this study, we assessed different spore traps for their capacity to capture Dc spores, and we developed a highly sensitive TaqMan qPCR method to quantify Dc conidia in spore trap samples. With these tools, we monitored the temporal and spatial spore dispersal and disease progress in spring and early summer in an extensively managed apple orchard in Switzerland in 2019 and 2020. Our results show that Dc overwinters in leaf litter and that spore dispersal and primary infections occur already in late April and beginning of May. We provide the first results on early-season spore dispersal of Dc, which, combined with the observed disease progress, helps to understand the disease dynamics and improve disease forecast models. Using the new qPCR method, we finally detected Dc in buds, on bark and on fruit mummies, suggesting that these apple organs may serve as additional overwintering habitats for the fungus.

Sustainable use of plant protection products in heroic viticulture areas. Reducing risks to the environment and winemaking.

Objective: The aim and objective of this article is to focus on the importance of the rational use of plant protection products to combat vine fungi and at the same time reduce their risks to human health and the environment. The integrated management of fungal diseases aims to achieve the development of healthy crops with the minimum alteration of agro-ecosystems and the promotion of natural mechanisms. Material and methods: The study was carried out in one vineyard in Ribeira Sacra (North-West Spain) during 2018. Souto vineyard is located at 438 m above mean sea level (42° 24' 27.67" N 7° 28' 20.06" W; northwest-southeast orientation) in the lower terraces of the river Sil's banks, following the contour lines and with gradients of up to 80%. The variety studied was Godello, for sampling the reproductive structures in the air (spores of Botrytis and Erysiphe and sporangia of Plasmopara), a Lanzoni VPPS-2000® spore trap (Lanzoni s.r.l., Bologna, Italy) was used. Results: The Botrytis Seasonal Spore Integral (SSIn) was markedly higher than for the other pathogens under consideration. Taking into account the maximum daily values, a clear dominance of Botrytis spores was also found, with a maximum of 397 spores/m3 at the beginning of June, while Erysiphe and Plasmopara were recorded at around 26 and 227 spores/m3, respectively, at the beginning of august and mid-July. The statistical analysis of the spore concentrations and the main meteorological variables showed for Erysiphe that the highest Spearman's r correlation coefficient corresponded to the rainfall, as for Plasmopara airbone sporangia, but with a negative sign, while for Botrytis spores, no significant correspondence was found for any meteorological parameter. Conclusion: The use of plant protection products can be much more effective if fungicides are applied at the right time, at the precise doses and combined with agricultural techniques of management of the vineyards. There are sustainable and profitable alternatives that can improve vine yields while protecting the environment in areas of heroic viticulture where the vineyard, is a fundamental element of the wine-growing landscape, combining as it does historical, cultural and landscape characteristics.

Airborne Pollens and their Association with Meteorological Parameters in the Atmosphere of Shiraz, Southwest Iran

Airborne pollen is considered one of the causative agents of hay fever, allergic rhinitis, conjunctivitis, and asthma. We aimed to investigate airborne pollens in the context of Shiraz located in the southwest of Iran and find their association with meteorological parameters. The survey was conducted from October 2017 to September 2018, using seven days of volumetric Burkard spore trap, located in the center of the city. A total of 5810 pollen grains/m3 belonging to 15 taxa were identified and recorded. Among them, 73.8% was the tree, while the grass, shrub, and weed constituted 13.56%, 3.5%, and 9.2% of total reported pollens, respectively. The major pollen types were Platanaceae (28.39%), Oleaceae (21.17%), Pinaceae (15.11%), Amaranthaceae (9.29%), and Brassicaceae (8.02%). A higher number of pollen counts and types were recorded in March, followed by September, while it was lower in May. Meteorological parameters were correlated with the monthly pollen counts. Wind speed was found to have a positive correlation with Platanaceae concentration. The significant correlation between pollen concentration and the temperature was positive for Poaceae, Amaranthaceae, and Plantaginaceae and negative for Rosaceae, Oleaceae, and Ulmaceae. Poaceae and Amaranthaceae were negatively correlated with humidity and positively with Rosaceae, Oleaceae, and Plantaginaceae. A negative correlation was found between rainfall and Poaceae and Amaranthaceae, while Plantaginaceae had a positive correlation with this parameter. The results of this study may be helpful for allergologists in the diagnosis and treatment of airborne allergic disorders due to pollen grains.

Low-Cost Spore Traps: An Efficient Tool to Manage Fusarium Head Blight through Improved Cropping Systems

Fusarium head blight (FHB) is a devastating disease of wheat. Worldwide, Fusarium graminearum is the most dominant FHB-causing species. Its most common toxin, deoxynivalenol (DON), impairs food and feed safety and has an enormous economic impact. Agronomic factors such as crop rotation, soil management and host genotype strongly influence the occurrence of F. graminearum. Infected plant debris from previous crops, on which perithecia and ascospores develop, represent the main source for FHB, and hence, improved cropping systems aim to reduce this inoculum to decrease the infection risk. The best measure to evaluate the disease pressure is spore traps that detect deposited airborne ascospores. Commercial spore traps are expensive and require power sources, thus, they are not suitable for investigations in field experiments with different treatments. In consequence, we developed spore traps containing a Petri dish with Fusarium-selective agar, protected by aluminum dishes and attached on a wooden board. We compared the data of our low-cost trap with those of a commercial high-throughput jet sampler and obtained equivalent results. In field experiments to compare cropping systems, we observed a high correlation between the DON content in wheat grains and the number of colonies from deposited spores. Our spore trap proved to be a highly valuable tool to not only study FHB epidemiology but also to identify innovative cropping systems with a lower risk for FHB and DON contamination.

Influence of a biological fungicide on the development and spreading of Alternaria alternata on vegetable crops

The effect of the biofungicide BFTIM KS-2, Zh on the development and spreading of the Alternaria alternata fungus on vegetable crops (tomato, pepper, eggplant) was studied using classical and modern methods of phytosanitary monitoring. The research was carried out in Krasnodar region in the Pavlovsky District, on the production fields of the ZAO Yubileinoye. To assess the development and spreading of the disease, the classical visual method was used, as well as a modern method for determining the congestion rate of plantings using the OZR-1mp spore trap.The article presents data on the development and spreading of A. alternata, the number of fungal spores on vegetable crops before and after treatments with the biofungicide. It was found that the use of the biological product reduces the development and spreading of the phytopathogen. Its influence is the most effective on tomato and eggplant crops. Also, in the course of research, the possibility of using a spore trap for monitoring Alternaria on vegetable crops has been shown.

Characterization of Pathogen Airborne Inoculum Density by Information Theoretic Analysis of Spore Trap Time Series Data

In a previous study, air sampling using vortex air samplers combined with species-specific amplification of pathogen DNA was carried out over two years in four or five locations in the Salinas Valley of California. The resulting time series data for the abundance of pathogen DNA trapped per day displayed complex dynamics with features of both deterministic (chaotic) and stochastic uncertainty. Methods of nonlinear time series analysis developed for the reconstruction of low dimensional attractors provided new insights into the complexity of pathogen abundance data. In particular, the analyses suggested that the length of time series data that it is practical or cost-effective to collect may limit the ability to definitively classify the uncertainty in the data. Over the two years of the study, five location/year combinations were classified as having stochastic linear dynamics and four were not. Calculation of entropy values for either the number of pathogen DNA copies or for a binary string indicating whether the pathogen abundance data were increasing revealed (1) some robust differences in the dynamics between seasons that were not obvious in the time series data themselves and (2) that the series were almost all at their theoretical maximum entropy value when considered from the simple perspective of whether instantaneous change along the sequence was positive.