Air analysis in the assessment of fumonisin contamination risk in maize.
BACKGROUND
In maize-growing areas where fumonisin contamination is endemic, there is an urgent need for novel methods to assess the quality of grain lots before their delivery to common drying and storage collection centres. Aerobiological samples of fungal spores released during harvest were analysed to establish a relationship between fumonisin contamination and the abundance of pathogen propagules collected in the combine harvester using a cyclone and membrane filters. Filter-captured propagules were analysed by direct plating, immunoenzymatic assay of specific Fusarium extracellular polysaccharides and real time polymerase chain reaction of the extracted DNA using fum1, a gene involved in the biosynthesis of fumonisin, as a target.


RESULTS
The results showed that time of harvest and environmental conditions strongly influenced the efficiency and performance of the collection system. The data obtained were informative in comparing individual samples collected under similar conditions. The immunoenzymatic assay provided the most reliable data, which improved the ability of a neural network to predict the fumonisin content of lots, when added to agronomic, environmental and phytosanitary data.


CONCLUSIONS
This is the first attempt to evaluate the Fusarium propagules dispersed during harvesting as a predictive means to assess maize quality. A method based on cyclone/filter capture and immunological detection has been shown to be feasible and to have the potential for the development of a continuous monitoring system, but the prediction capabilities in the present implementation were limited.
Torelli
Emanuela
E
Dipartimento di Biologia e Protezione delle Piante, University of Udine, Via delle Scienze 208, I-33100 Udine, Italy.
Gubiani
Rino
R
Firrao
Giuseppe
G
Cividino
Sirio
S
Locci
Romano
R
Gobbi
Emanuela
E
D000383:Agriculture / Q000379:methods; D000388:Air; D004271:DNA, Fungal / Q000032:analysis; D002523:Edible Grain / Q000382:microbiology; D004777:Environment; D005374:Filtration / Q000379:methods; D005504:Food Analysis / Q000379:methods*; D005516:Food Microbiology; D037341:Fumonisins / Q000302:isolation & purification* / Q000378:metabolism; D005670:Fusarium / Q000235:genetics / Q000302:isolation & purification*; D005800:Genes, Fungal; D016571:Neural Networks, Computer; D010935:Plant Diseases / Q000382:microbiology; D011134:Polysaccharides / Q000032:analysis; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012306:Risk; D013172:Spores, Fungal / Q000235:genetics*; D003313:Zea mays / Q000382:microbiology*
D004271:DNA, Fungal; D037341:Fumonisins; D011134:Polysaccharides