Microsatellite markers used for genome-wide association mapping of partial resistance to <Emphasis Type="Italic">Sclerotinia sclerotiorum</Emphasis> in a world collection of <Emphasis Type="Italic">Brassica napus</Emphasis>

The fungal pathogen Sclerotinia sclerotiorum causes stem rot of oilseed rape (Brassica napus) worldwide. In preparation for genome-wide association mapping (GWAM) of sclerotinia resistance in B. napus, 152 accessions from diverse geographical regions were screened with a single Canadian isolate, #321. Plants were inoculated by attaching mycelium plugs to the main stem at full flower. Lesion lengths measured 7, 14 and 21 days after inoculation were used to calculate the area under the disease progress curve (AUDPC). Depth of penetration was noted and used to calculate percent soft and collapsed lesions (% s + c). The two disease traits were highly correlated (r = 0.93). Partially resistant accessions (AUDPC <7 and % s + c <2) were identified primarily from South Korea and Japan with a few from Pakistan, China and Europe. Genotyping of accessions with 84 simple sequence repeat markers provided 690 polymorphic loci for GWAM. The general linear model in TASSEL best fitted the data when adjusted for population structure (STRUCTURE), GLM + Q. After correction for positive false discovery rate, 34 loci were significantly associated with both disease traits of which 21 alleles contributed to resistance, while the remaining enhanced susceptibility. The phenotypic variation explained by the loci ranged from 6 to 25 %. Five loci mapped to published quantitative trait loci conferring sclerotinia resistance in Chinese lines.     

QTL analysis and the development of closely linked markers for days to flowering in spring oilseed rape (<Emphasis Type="Italic">Brassica napus</Emphasis> L.)

Days to flowering (DTF) is an important trait impacting cultivar performance in oilseed rape (Brassica napus L.), but the interaction of all loci controlling this trait in spring-type oilseed rape is not fully understood. We identified quantitative trait loci (QTL) for variation in DTF in a doubled haploid (DH) population from the Qinghai–Tibet Plateau that includes 217 lines derived from a cross between spring-type oilseed rape (B. napus L.) line No. 5246 and line No. 4512, the latter of which is responsive to the effective accumulated temperature (EAT). A linkage map was constructed for the DH population, using 202 SSR and 293 AFLP markers. At least 22 DTF QTL were found in multiple environments. Four major QTL were located on linkage groups A7, C2, C8 and C8. Among these QTL, cqDTFA7a and cqDTFC2a were identified in five environments and individually explained 10.4 and 23.0 % of the trait variation, respectively. cqDTFC8, a major QTL observed in spring environments, and a unique winter environment QTL, qDTFC8-3, were identified; these QTL explained 10.0 and 46.5 % of the phenotypic variation, respectively. Minor QTL (for example, cqDTFC2c) and epistatic interactions seemed evident in this population. Two closely linked SSR markers for cqDTFA7a and cqDTFC8 were developed (G1803 and S034). BnAP1, a B. napus gene with homology to Arabidopsis thaliana that was identified as a cqDTFA7a candidate gene, played a major role in this study. The allelic effects of the major and minor QTL on DTF were further validated in the DH population and in 93 breeding genotypes.     

Analyses of air samples for ascospores ofLeptosphaeria maculans andL.biglobosa by light microscopy and molecular techniques

Spores of many fungal pathogens are dispersed by wind. Detection of these airborne inocula is important in forecasting both the onset and the risk of epiphytotics. Species-specific primers targeted at the internal transcribed spacer (ITS) region ofLeptosphaeria maculans andL. biglobosa — the causal organisms of phoma stem canker and stem lesions ofBrassica spp., including oilseed rape — were used to detect DNA extracted from particles deposited on tapes obtained from a spore trap operated in Rarwino (northwest Poland) from September to November in 2004 and 2006. The quantities of DNA assessed by traditional end-point PCR and quantitative real-time PCR were compared to microscopic counts of airborne ascospores. Results of this study showed that fluctuations in timing of ascospore release corresponded to the dynamics of combined concentrations of DNA fromL. maculans andL. biglobosa, with significant positive correlations between ascospore number and DNA yield. Thus the utilization of PCR-based molecular diagnostic techniques enabled the detection, identification, and accurate quantification of airborne inoculum at the species level. Moreover, real-time PCR was more sensitive than traditional PCR, especially in years with low ascospore numbers.     

Quantitative PCR analysis of abundance of airborne propagules of Leptosphaeria species in air samples from different regions of Poland

When airborne propagules of Leptosphaeria maculans and L. biglobosa were collected in Poland at three ecologically different sites from 1 September to 30 November in 2004 to 2008, using a Hirst-type seven-day volumetric spore trap, there were fluctuations in timing of ascospore release and diverse ratios between airborne propagules of both species depending on season, field location and weather conditions. The detection was done using the microscope as well as quantitative PCR with species-specific primers targeted against fragments of β-tubulin genes and quantified with a dual-labelled fluorescent probe approach. This detection chemistry is described for the first time for L. maculans and L. biglobosa. Its advantage over the previous ITS-based SYBR-Green chemistry resides in improved sensitivity and the virtual absence of false positives in the detection of these fungi. There were significant, positive correlations between data obtained using visual assessment of ascospore numbers and DNA concentrations that were measured by qPCR. Climatic differences between the oilseed rape growing regions could have significantly affected the biological processes of pseudothecial maturation and ascospore development of the pathogens. The data suggest that regular rain events of intermediate intensity recorded in the Maritime region favoured the maturation of the pathogen more than the drier weather recorded in the Silesia or Pomerania regions. It was observed that the number of rainy days was of greater importance than the cumulative rainfall to obtain the generative sporulation of the pathogen. Accurate detection of airborne inoculum of pathogenic Leptosphaeria spp. facilitates improved targeting of disease management decisions for oilseed rape protection against phoma stem canker and stem necrosis diseases.     

Atmospheric concentrations and intradiurnal pattern of <Emphasis Type="Italic">Alternaria</Emphasis> and <Emphasis Type="Italic">Cladosporium</Emphasis> conidia in Tétouan (NW of Morocco)

Fungal spores of Alternaria and Cladosporium are ubiquitous components of both indoor and outdoor air samples and are the main causes of human respiratory allergies. Monitoring these airborne fungal spores during 2009–2014 was carried out by means of Hirst-type spore trap to investigate their airborne spore concentrations with respect to annual load, seasonality and overall intradiurnal pattern. Alternaria and Cladosporium spores are present throughout the year in the atmosphere of Tétouan, although they show seasonal variations. Despite important differences between years, their highest levels presented a first peak during spring and a higher second peak in summer or autumn depending on the year. The spore concentrations were homogeneously distributed throughout the day with slight increase of 7.6 and 3.7% on average between 12–14 and 14–16 h for Alternaria and Cladosporium, respectively. The borderline of 3000 sp/m³ of Cladosporium linked to the occurrence of allergic diseases was exceeded between 13 and 31 days. Airborne spores of Alternaria overcame the threshold value of 100 sp/m³ up to 95 days, suggesting that Cladosporium and Alternaria could be clinically significant aeroallergens for atopic patients.     

Phosphinothricin-resistant <Emphasis Type="Italic">Brassica napus</Emphasis> + <Emphasis Type="Italic">Orychophragmus violaceus</Emphasis> somatic hybrids

Hybrid plants resistant to phosphinothricin (PPT) are obtained as a result of experiments with somatic hybridization between Brassica napus L. cv. Kalinins’kyy and Orychophragmus violaceus L. O.E. Shulz. The hybrids inherited PPT resistance from O. violaceus plants that had been previously transformed by a vector containing the maize transposon system Spm/dSPm with bar gene located within the nonautonomous transposon. The morphologically obtained plants occupy an intermediate position between the initial forms, which is in agreement with the results of isoenzyme analyses (analysis of multiple forms of amylase and esterase) and PCR analysis (presence of the genes bar, gus, and SpmTPase). Inheritance of the plastome occurs from oilseed rape, while that of the mitochondrion, from O. violaceus, which is proved by means of PCR-RFLP analysis. The plant hybrids may be utilized for further selection research with oilseed rape following determination of the edible quality of its oil as well as in experiments with chloroplast transformation, a topic which is of critical importance for oilseed rape.     

Impact of insecticides on oilseed rape bud infestation with eggs and larvae of pollen beetle (<Emphasis Type="Italic">Brassicogethes aeneus</Emphasis> (Fabricius))

One of the main insect pests in oilseed rape is the pollen beetle (Brassicogethes aeneus (Fabricius), syn. Meligethes aeneus). To maximize efficiency of control of this pest, insecticides are required that ideally, not just prevent yield losses by bud feeding of overwintered pollen beetles, but simultaneously minimize the reproduction of the pest, thereby reducing the size of the following generation infesting next year’s oilseed rape. The neonicotinoid active substance thiacloprid is known to reduce bud infestation with eggs and larvae. However, the mechanisms by which this occurs as well as the effects of other active substances are not known. In this study, the effects of the neonicotinoid insecticide Biscaya (a.i. thiacloprid) and the pyrethroids Mavrik (tau-fluvalinate) and Karate Zeon (lambda-cyhalothrin) applied at the bud stage of winter oilseed rape with recommended field rates on infestation of buds with eggs and larvae of pollen beetles were tested in field trials in Germany in 2013–2015. In additional greenhouse experiments, it was investigated whether effects on bud infestation were caused by lethal effects on pollen beetle or by insecticidal residues on plants causing sublethal effects. In the field trials, application of Biscaya and Mavrik significantly reduced the percentage of buds containing eggs and larvae in contrast to Karate Zeon. In 2014 and 2015, 14 days after application, bud infestation on the main raceme was reduced by 86 and 82%, respectively, in Biscaya-treated plots and by 51 and 71%, respectively, in Mavrik-treated plots compared to the untreated plots. In the greenhouse experiments, the lowest percentage of bud infestation with eggs and larvae was recorded on Biscaya-treated plants whereas on Mavrik-treated plants, there was no significant difference compared with the control. The results of the field trials show that Biscaya and Mavrik reduced oilseed rape bud infestation with eggs and larvae of pollen beetles primarily by lethal effects on overwintered pollen beetles or by repellency. However, Biscaya had additional effects on egg laying, which was supported by the greenhouse experiments.     

Development of a powder formulation based on <Emphasis Type="Italic">Bacillus</Emphasis><Emphasis Type="Italic">cereus</Emphasis> sensu lato strain B25 spores for biological control of <Emphasis Type="Italic">Fusarium verticillioides</Emphasis> in maize plants

Maize is an economically important crop in northern Mexico. Different fungi cause ear and root rot in maize, including Fusarium verticillioides (Sacc.) Nirenberg. Crop management of this pathogen with chemical fungicides has been difficult. By contrast, the recent use of novel biocontrol strategies, such as seed bacterization with Bacillus cereus sensu lato strain B25, has been effective in field trials. These approaches are not without their problems, since insufficient formulation technology, between other factors, can limit success of biocontrol agents. In response to these drawbacks, we have developed a powder formulation based on Bacillus B25 spores and evaluated some of its characteristics, including shelf life and efficacy against F. verticillioides, in vitro and in maize plants. A talc-based powder formulation containing 1 × 10⁹ c.f.u. g^?1 was obtained and evaluated for seed adherence ability, seed germination effect, shelf life and antagonism against F. verticillioides in in vitro and in planta assays. Seed adherence of viable bacterial spores ranged from 1.0 to 1.41 × 10⁷ c.f.u. g^?1. Bacteria did not display negative effects on seed germination. Spore viability for the powder formulation slowly decreased over time, and was 53 % after 360 days of storage at room temperature. This formulation was capable of controlling F. verticillioides in greenhouse assays, as well as eight other maize phytopathogenic fungi in vitro. The results suggest that a talc-based powder formulation of Bacillus B25 spores may be sufficient to produce inoculum for biocontrol of maize ear and root rots caused by F. verticillioides.     

Inhibitory effects of xenocoumacin 1 on the different stages of <Emphasis Type="Italic">Phytophthora capsici</Emphasis> and its control effect on Phytophthora blight of pepper

Phytophthora species cause enormous economic loss every year worldwide. Xenocoumacin 1 (Xcn1), isolated from the bacterium Xenorhabdus nematophilus, is a broad-spectrum antibiotic against agricultural pathogens, especially Phytophthora. To understand the inhibitory mode of Xcn1 toward Phytophthora pathogens, we determined the inhibitory effects of Xcn1 on Phytophthora capsici both in vitro and in vivo. In vitro, Xcn1 inhibited different stages in the life cycle of P. capsici, including sporangium formation, zoospore germination, and mycelial growth, with 50% effective concentration (EC₅₀) values of 0.037, 0.81, and 2.44 μg ml^?1, respectively. Xcn1 also reduced zoospore motility. In vivo, Xcn1 efficiently controlled the Phytophthora blight of pepper with a disease reduction of 99% at a concentration of 5 μg ml^?1 assessed on the third day after incubation of wound stem plants. In addition, Xcn1-treated P. capsici mycelia exhibited increased mycelial branch spacing, evident plasmolysis, and leakage of intracellular components. In conclusion, in the presence of Xcn1, several stages in the life cycle of P. capsici were inhibited, and the hyphae exhibited obvious morphological changes.     

Effects of temperature and rainfall on date of release of ascospores of Leptosphaeria maculans (phoma stem canker) from winter oilseed rape (Brassica napus) debris in the UK

Data from a controlled environment experiment investigating effects of temperature on maturation of Leptosphaeria maculans pseudothecia were used to derive equations describing the times until 30% or 50% of pseudothecia were mature as a function of temperature. A wetness sensor was developed to estimate the oilseed rape debris wetness and operated with debris exposed in natural conditions in 2000 and 2001. The maturation of L. maculans pseudothecia on debris and concentrations of airborne L. maculans ascospores were observed from 1999 to 2004. There were considerable differences between years, with the first mature pseudothecia observed in September in most years. There were linear relationships between the first date when 10% of maximum ascospore release was observed and the dates when 30% or 50% of pseudothecia were mature. By summing the daily temperature‐dependent rate of pseudothecial maturation for days after 1 August with rainfall >0.5 mm, the dates when 30% or 50% of pseudothecia were mature were predicted. There was good agreement between predicted and observed dates when 30% or 50% of pseudothecia were mature. These equations for predicting the timing of L. maculans ascospore release could be incorporated into schemes for forecasting, in autumn, the severity of phoma stem canker epidemics in the following spring/summer in the UK.     

Effects of wind speed and direction on monthly fluctuations of <Emphasis Type="Italic">Cladosporium</Emphasis> conidia concentration in the air

This study determined the relationship between airborne concentration of Cladosporium spp. spores and wind speed and direction using real data (local wind measured by weather station) and modelled data (air mass flow computed with the aid of HYbrid Single Particle Lagrangian Trajectory model). Air samples containing fungal conidia were taken at an urban site (Worcester, UK) for a period of five consecutive years using a spore trap of the Hirst design. A threshold of ≥6000 s m^?3 (double the clinical value) was applied in order to select high spore concentration days, when airborne transport of conidia at a regional scale was more likely to occur. Collected data were then examined using geospatial and statistical tools, including circular statistics. Obtained results showed that the greatest numbers of spore concentrations were detected in July and August, when C. herbarum, C. cladosporioides and C. macrocarpum sporulate. The circular correlation test was found to be more sensitive than Spearman’s rank test. The dominance of either local wind or the air mass on Cladosporium spore distributions varied between examined months. Source areas of this pathogen had an origin within the UK territory. Very high daily mean concentrations of Cladosporium spores were observed when daily mean local wind speed was v _s ≤ 2.5 m s^?1 indicating warm days with a light breeze.     

First volumetric record of fungal spores in the atmosphere of Montevideo City,Uruguay: a 2-year survey

In Uruguay, aeromycological studies are restricted to a gravimetric analysis performed from December 1942 to March 1944 in Montevideo where spores of Pucciniaceae, Alternaria and Helminthosporium were the only specimens identified. Daily monitoring of airborne fungal spores was carried out for the first time in Montevideo, from April 2012 to March 2014, using a Rotorod sampler in order to evaluate the seasonal variation and influence of meteorological parameters. A total of 548,309.68 spores/m³ were recorded which belong to anamorphs of Higher Fungi (69.18 %), Phyla Ascomycota (12.62 %), Basidiomycota (8.01 %), Oomycota (0.37 %) and Myxomycota (0.06 %). Airborne spores occurred in Montevideo throughout the whole year. However, a seasonal pattern was revealed, with the highest concentrations recorded in autumn and summer. The most abundant spore types were Cladosporium (53.22 %), Alternaria (6.62 %), Didymella Group (5.86 %), Leptosphaeria Group (4.37 %) and Coprinus (4.3 %). Temperature appeared to be the most influential meteorological factor correlating significantly and positively with total spore, Cladosporium, Alternaria and Didymella Group abundance. Relative humidity influenced positively total spore, Cladosporium and Didymella Group concentrations while a weak negative association was obtained for Alternaria. Wind speed correlated negatively with total spore, Cladosporium, Alternaria and Didymella Group. Precipitation showed a negative influence on Alternaria, while positive correlations were observed for Didymella Group. For the first time, fungal spores considered allergenic were recorded in Montevideo atmosphere and the risk of exposure would have been high from December to June. However, long-term sampling is needed to define seasonal prevalence patterns and the influence of meteorological conditions on spore abundance.     

Development of INDELs markers in oilseed rape (<Emphasis Type="Italic">Brassica napus</Emphasis> L.) using re-sequencing data

Insertions/deletions (INDELs), a type of abundant length polymorphisms in the plant genomes, combine the characteristics of both simple sequence repeats (SSRs) and single-nucleotide polymorphisms (SNP), and thus can be developed as desired molecular markers for genetic studies and crop breeding. There has been no large-scale characterization of INDELs variations in Brassica napus yet. In this study, we identified a total of 538,691 INDELs in size range of 1–10 bp by aligning whole-genome re-sequencing data of 23 B. napus inbred lines (ILs) to the B. napus genome sequence of ‘Darmor-bzh.’ Of these, 104,190 INDELs were uniquely mapped on the pseudochromosomes of the reference genome. A set of 595 unique INDELs of 2–5 bp in length was selected for experimental validation in the 23 ILs. Of these INDELs, 530 (89.01 %) produced a single PCR product and were single locus. A total of 523 (87.9 %) INDELs were found polymorphic among the 23 ILs. A genetic linkage map containing 108 single-locus INDELs and 89 anchor SSR markers was constructed using 188 recombinant ILs. The majority of INDELs markers on the linkage map showed consistency with the pseudochromosomes of the B. napus cultivar ‘Darmor-bzh.’ The INDELs variations and markers reported here will be valuable resources in future for genetic studies and molecular breeding in oilseed rape.     

Dual effects of single-walled carbon nanotubes coupled with near-infrared radiation on <Emphasis Type="Italic">Bacillus anthracis</Emphasis> spores: inactivates spores and stimulates the germination of surviving spores

Background

Bacillus anthracis is a pathogen that causes life-threatening disease--anthrax. B. anthracis spores are highly resistant to extreme temperatures and harsh chemicals. Inactivation of B. anthracis spores is important to ensure the environmental safety and public health. The 2001 bioterrorism attack involving anthrax spores has brought acute public attention and triggered extensive research on inactivation of B. anthracis spores. Single-walled carbon nanotubes (SWCNTs) as a class of emerging nanomaterial have been reported as a strong antimicrobial agent. In addition, continuous near infrared (NIR) radiation on SWCNTs induces excessive local heating which can enhance SWCNTs’ antimicrobial effect. In this study, we investigated the effects of SWCNTs coupled with NIR treatment on Bacillus anthracis spores.

Results and discussion

The results showed that the treatment of 10 μg/mL SWCNTs coupled with 20 min NIR significantly improved the antimicrobial effect by doubling the percentage of viable spore number reduction compared with SWCNTs alone treatment (88% vs. 42%). At the same time, SWCNTs-NIR treatment activated the germination of surviving spores and their dipicolinic acid (DPA) release during germination. The results suggested the dual effect of SWCNTs-NIR treatment on B. anthracis spores: enhanced the sporicidal effect and stimulated the germination of surviving spores. Molecular level examination showed that SWCNTs-NIR increased the expression levels (>2-fold) in 3 out of 6 germination related genes tested in this study, which was correlated to the activated germination and DPA release. SWCNTs-NIR treatment either induced or inhibited the expression of 3 regulatory genes detected in this study. When the NIR treatment time was 5 or 25 min, there were 3 out of 7 virulence related genes that showed significant decrease on expression levels (>2 fold decrease).

Conclusions

The results of this study demonstrated the dual effect of SWCNTs-NIR treatment on B. anthracis spores, which enhanced the sporicidal effect and stimulated the germination of surviving spores. SWCNTs-NIR treatment also altered the expression of germination, regulatory, and virulence-related genes in B. anthracis.

     

Atmospheric concentrations of selected allergenic fungal spores in relation to some meteorological factors,in Timişoara (Romania)

Present investigation was undertaken to study the dynamics of relationships between atmospheric fungal spores and meteorological factors in western Romania. The airborne spore sampling was carried out by employing volumetric sampling. A total of nine meteorological parameters were selected for this investigation. During 2008–2010, it was found the same pattern of behaviour in the atmosphere for selected spore types (Alternaria, Cladosporium, Pithomyces, Epicoccum and Torula). The spores occurred in the air throughout the whole year, but maximum concentrations were reached in summer. Cladosporium and Alternaria peak levels were observed in June. Epicoccum peak value was found in September. The relationships between airborne spore concentrations and environmental factors were assessed using the analysis of Spearman’s rank correlations and multiple linear regressions. Spearman’s rank correlation analysis revealed that maximum, minimum and mean temperature, and number of sunshine hours were strongly (p < 0.01) and directly proportional to the concentration of all analysed fungal spores. Negative and significant correlations were with daily mean relative humidity. The variance explained percentage by regression analyses varied between 30.6 and 39.6 % for Alternaria and Cladosporium airborne spores. Statistical methods used in this study are complementary and confirmed stable dependence of Alternaria and Cladosporium spore concentrations on meteorological factors. The climate change parameters either increased temperatures, changed precipitation regimes or a combination of both affected allergenic fungal spore concentrations in western Romania. This study demonstrates the need for investigations throughout the year, from month to month, regarding the correct interpretation of airborne spore relationships with meteorological parameters.     

Impact of elevated CO<Subscript>2</Subscript> in <Emphasis Type="Italic">Casuarina equisetifolia</Emphasis> rooted stem cuttings inoculated with <Emphasis Type="Italic">Frankia</Emphasis>

Impact of different levels of elevated CO ₂ on the activity of Frankia (Nitrogen-fixing actinomycete) in Casuarina equisetifolia rooted stem cuttings has been studied to understand the relationship between C. equisetifolia, Frankia and CO₂. The stem cuttings of C. equietifolia were collected and treated with 2000 ppm of Indole Butyric Acid (IBA) for rooting. Thus vegetative propagated rooted stem cuttings of C. equisetifolia were inoculated with Frankia and placed in the Open top chambers (OTC) with elevated CO₂ facilities. These planting stocks were maintained in the OTC for 12 months under different levels of elevated CO₂ (ambient control, 600 ppm, 900 ppm). After 12 months, the nodule numbers, bio mass, growth, and photosynthesis of C. equisetifolia rooted stem cuttings inoculated with Frankia were improved under 600 ppm of CO₂. The rooted stem cuttings of C. equisetifolia inoculated with Frankia showed a higher number of nodules under 900 ppm of CO₂ and cuttings without Frankia inoculation exhibited poor growth. Tissue Nitrogen (N) content was also higher under 900 ppm of CO₂ than ambient control and 600 ppm levels. The photosynthetic rate was higher (17.8 μ mol CO₂ m^?2 s^?1) in 900 ppm of CO₂ than in 600 ppm (13.2 μ mol CO₂ m^?2 s^?1) and ambient control (8.3 μ mol CO₂ m^?2 s^?1). This study showed that Frankia can improve growth, N fixation and photosynthesis of C. equietifolia rooted stem cuttings under extreme elevated CO₂ level conditions (900 ppm).     

Monitoring of anamorphic fungal spores in Madeira region (Portugal), 2003–2008

Seven years of aeromycological study was performed in the city of Funchal with the purpose to determine the anamorphic spore content of this region and its relationship to meteorological factors. The sampling was carried out with a Hirst-type volumetric spore trap following well-established guidelines. A total of 17,586 anamorphic fungal spores were recorded during the studied period, attaining an annual average concentration of 2931 spores m^?3. Anamorphic fungal spores were observed throughout the year, although the major peaks were registered during spring (April–June) and autumn period (September–November). The lowest spore levels were recorded between December and February months. Over 14 taxa of anamorphic fungal spores were observed with Cladosporium being the most prevalent fungal type accounting for 78 % of the total conidiospores. The next in importance was Alternaria (5.4 %), Fusarium (4.7 %), Torula (3.9 %) and Botrytis (1.9 %). Temperature was the meteorological parameter that favoured the most release and dispersal of the conidiospores, whereas rainfall revealed a negative effect. Despite the low concentration levels found in our region, the majority of the fungal types identified are described as potential aeroallergens. This study provides the seasonal variation of the conidiospores and the periods when the highest counts may be expected, representing a preventive tool in the allergic sensitization of the population.