Detection of Curtobacterium flaccumfaciens pv. flaccumfaciens in Bean Seeds and in Seeds of Other Leguminosae Crops

Curtobacterium flaccumfaciens pv. flaccumfaciens (Hedges) Collins & Jones is the causal agent of a systemic vascular disease called bacterial wilt of beans.C. flaccumfaciens pv. flaccumfaciens is widely distributed. Besides the United States and Canada, it has been reported in most of the bean-producing countries in the world, such as Australia, Brazil, Columbia, Venezuela, Mauritius, Kenya, Tunisia, Bulgaria, Romania, Russia, Spain, Turkey, Ukraine, and former Yugoslavia, reported according to their continent (5, 26, 84). It was reported in Greece and Hungary, where it never became established, while reports from Belgium, France, Germany, and Switzerland have not been confirmed (23, 63). C. flaccumfaciens pv. flaccumfaciens is a quarantine pathogen for Europe, belonging to the EPPO A2 list of pests recommended for regulation. Bacterial wilt losses, both in terms of seed yield and bean quality, can vary according to the host species, environmental conditions, and agricultural practices. Because C. flaccumfaciens pv. flaccumfaciens– infected seeds do not always show clear symptoms, visual inspection of seed lots is unreliable as a seed health assay. Therefore, other assays have been developed, such as agar plating on semiselective media, seedling inoculation, serological methods, physiological tests (such as Biolog MicroPlates), and genomic fingerprinting. Because of the urgent need for high-throughput, effective, and low-cost protocols for routine seed health testing, PCR-based assays have been here developed with increased sensitivity and specificity for C. flaccumfaciens pv. flaccumfaciens