Improved aeroponic culture technique for production of inocula of arbuscular mycorrhizal fungi

We compared the conventional atomizing disc aeroponic technology with the latest ultrasonic nebulizer technology for the production of Glomus intraradices inocula. The piezo ceramic element technology used in the ultrasonic nebulizer employed high frequency sound that blasted the nutrient solution and nibulized it into micro-droplets size of 1μm in diameter. Growth of the pre-colonized AMF-roots of Sudan grass was successfully achieved in both the chambers used in this study but root growth and mycorrhization was statistically faster and higher in the ultrasonic nebulizer aeroponic system than in the atomizing disc aeroponic system. The shearing of the AMF infected roots from both the systems did not result in the loss of inoculum viability as evident from the MPN data. However, MPN assay showed that sheared roots produced using the ultra-sonic nebulizer system had a significantly higher number of infective propagules than those produced by the atomizing disc system. Our findings indicate that the latest ultra-sonic nebulizer aeroponic technology is superior, and can be an alternative to conventional atomizing disc or spray nozzle systems for a high quality concentration of AMF isolates which can be used in small doses to produce large response, a pre-requisite for commercialization of AMF technology.