Rapid molecular methods for plant disease diagnosis

Authors

  • Adesh Ramsubhag Department of Life Sciences, Faculty of Science and Technology, The University of the West Indies
  • Jayaraj Jayaraman Department of Life Sciences, Faculty of Science and Technology, The University of the West Indies

Keywords:

Molecular methods, disease diagnosis, pathogen detection

Abstract

Proper diagnosis is critical for effective management of plant diseases. Traditional microscopic and culture-based techniques generally require a long time for completion, are often subjective and cannot resolve identity of pathogens at low levels of taxa. Methods based on serology, analysis of fatty acids and carbon utilization profiles are also available but are not always suited for tropical isolates because of strain variations and their limited representations in diagnostic databases. The advent of revolutionary polymerase chain reaction and nucleic acid sequencing-based methods now make it possible for accurate and rapid detection and identification of plant pathogenic agents, without having to culture the organisms. ˜This paper discusses the development and application of these molecular methods for plant disease diagnosis and their relevance to integrated disease management. The use of single-plex and multi-plex PCR, RT-PCR and real-time PCR together with Sanger and next-generation sequencing are highlighted in identifying pathogens at different taxonomic levels. Emerging technologies such as deep sequencing of small RNA for detecting unique viruses infecting plants and spectrometric-based identification systems are also discussed.