Evaluation of the Burkard cyclonic spore sampler for collection efficiencyof ascospores

The commercially available Burkard cyclonic sampler takes in air volumetric ally, creates a vortex in an aluminum cylinder, and deposits particulates i n an Eppendorf vial. Retention within the cylinder was determined for ascos pores released by cultures of Sordaria fimicola and Gibberella zeae. Manufa cturer's recommended amperage level and reduced power were tested, and a su rfactant was applied to the cylinder wall. Under recommended power, an aver age of 78% of the S. fimicola ascospores were collected in the vial, while 22% lodged inside the cylinder. Conversely, only 25% of the G. zeae ascospo res were collected in the vial, while 75% remained lodged inside the cylind er. Application of a surfactant to reduce the adherence of ascospores on th e cylinder wall, instead resulted in 83% of the S. fimicola ascospores and 99.7% of the G. zeae ascospores deposited on the cylinder wall. When the po wer supply was decreased from 200 mA to 140 mA, the ratio of ascospores of G. zeae retained by the sampler remained nearly the same, indicating that t he retention error was not a function of airflow rate within the tested pow er range. However, the total number of ascospores collected was significant ly less under reduced power. A 90-A/h (12 V) battery supplied greater than 150 mA when connected to the Burkard for 4 days at temperatures between 22 and 28 degreesC and could maintain current above 190 mA for 7 days with a 2 1-W solar panel. A 21-W solar panel charging a 90-A/h battery should mainta in the amperage needed for the Burkard to maintain proper flow rate in most environments. The aluminum cylinder should be rinsed out thoroughly when c ollecting samples of fungal ascospores or any other particulates with the p ropensity to adhere to the cylinder wall.