Impacts of molecular diagnostic technologies on plant disease management

Detection and diagnosis of plant viruses has included serological laborator y tests since the 1960s. Relatively little work was done on serological det ection of plant pathogenic bacteria and fungi prior to the development of E LISA and monoclonal antibody technologies. Most applications for laboratory -based tests were directed at virus detection with relatively little emphas is on fungal and bacterial pathogens, though there was some good work done with other groups of plant pathogens. With the advent of molecular biology and the ability to compare regions of genomic DNA representing conserved se quences, the development of laboratory tests increased at an amazing rate f or all groups of plant pathogens. Comparison of ITS regions of bacteria, fu ngi, and nematodes has proven useful for taxonomic purposes. Sequencing of conserved genes has been used to develop PCR-based detection with varying l evels of specificity for viruses, fungi, and bacteria. Combinations of ELIS A and PCR technologies are used to improve sensitivity of detection and to avoid problems with inhibitors or PCR often found in plants. The applicatio n of these technologies in plant pathology has greatly improved our ability to detect plant pathogens and is increasing our understanding of, their ec ology and epidemiology.