Development of a simple on-farm colourimetric loop-mediated isothermal amplification DNA assay (AgTIY–RSDetect) for the detection of Leifsonia xyli subsp. xyli in sugarcane

Ratoon stunting disease (RSD), caused by the bacterium Leifsonia xyli subsp. xyli, generates significant yield losses in sugarcane crops (Saccharum hybrids) worldwide. Existing methods, such as qPCR are costly and time consuming, requiring sample submission to a central laboratory and testing with expensive equipment. To enable better disease management, a new RSD test method using colourimetric Loop-Mediated Isothermal Amplification (LAMP) DNA assay has been developed for cheaper, faster, grower-screening of plants for RSD infection on farm (AgTIY–RSDetect). The colorimetric reporting system used in AgTIY–RSDetect is highly visual and can be undertaken within an hour of sample collection, making it an excellent extension tool for growers and agronomists. Requiring a small, inexpensive set up, the rapid turn-around time enables growers to respond quickly to field infections and allows alternative plants to be sourced or targeted disease management strategies implemented in a timely manner.