Monitoring for plant pathogens currently relies on detection of symptoms by suitably skilled personnel. The difficulties of distinguishing diseases based on symptoms, and of timing surveillance to coincide with symptom expression, can result in new pathogens not being detected until they are already widespread.
In epidemiological studies, monitoring has relied on symptom expression in crops or trap plants. However, there may be logistical challenges in assuring a timely supply of trap plants, and the amount of inoculum may be underestimated if conditions are suboptimal for disease development. The combination of air sampling and molecular diagnostics allows fast, reliable, accurate, sensitive and specific detection of air-borne fungal pathogens. Research is underway to develop methodology for nucleic acidbased detection and quantification of fungal plant pathogens from spore traps, using pathogens of pulse and oilseed crops as models. Sensitivity, specificity and factors affecting detection thresholds, such as temperature, relative humidity and presence of non-target particles will be determined. The robustness of the methodology in answering epidemiological questions of potential importance in plant biosecurity, such as the distance, direction, rate and timing of spread of pathogens, will be tested. As it is difficult to predict which exotic pathogens will enter, become established and cause significant losses in a new area, research is also proposed into the detection of unanticipated plant pathogens in spore traps, using nucleic acid-based community profiling methods. This approach may lead to early detection of incursions, early warning of epidemics and identification of weather conditions favouring aerial dispersal of spores.