Latent potential of current plant diagnostics for detection of sugarcane diseases

Abstract

This review evaluates the usability of commonly used techniques for sugarcane sample preparation and pathogen detection, emphasising on-site diagnostics, and the associated challenges. A critical analysis of state-of-the-art methods to overcome these challenges is also presented. • The importance of on-site diagnostics for early detection sugarcane diseases causative organisms is described. • Commonly used techniques for sugarcane sample preparation and pathogen detection are described. • Currently available portable devices for on-site diagnostics are critically evaluated. • The biological and technical challenges of on-site detection are addressed. • A critical analysis of state-of-the-art methods to overcome these challenges is presented. Cropping industries are impacted by multiple biotic constraints that result in significant economic and productivity losses due to pests and diseases, and disease management costs both pre- and post-harvest. Bacterial, fungal, and viral pathogens are estimated to cause 16% of global crop losses pre-harvest, and thus accurate and informed disease management is required to ensure optimal yields. Significant economic risks are posed by several major diseases, which require host management approaches and accurate, sensitive, and rapid detection of the causative organisms to inform plant disease management. Over the last decade, many methods have been developed for detecting disease-causing organisms using enzyme-linked immunosorbent assays, real-time polymerase chain reaction, microarray, and loop-mediated isothermal amplification based tools. Most of these methods are highly selective and specific but unsuitable for on-site application. These methods are time consuming and require complex instrumentation. Sugarcane is a major cash crop in Australia with economic activity of over a billion dollars annually and many billions more globally, and thus there is a need to develop rapid on-site diagnostic tools with less complex assays for the early detection of sugarcane pathogens. This review considers the usability of commonly used sugarcane sample preparation and pathogen detection techniques, with a particular focus on on-site diagnostics and the associated challenges. In addition, the state-of-the-art methods for overcoming these challenges are critically analyzed.