Curtobacterium flaccumfaciens pv. flaccumfaciens

Curtobacterium flaccumfaciens pv. flaccumfaciens is the causal agent of the bacterial wilt disease of Phaseolus spp. and is a systemic bacterium. The disease was first discovered in the United States (South Dakota) in the 1920s on Phaseolus vulgaris and subsequently recorded in Australia, Canada, Mexico, South America and Tunisia. It has a restricted distribution inRomania andRussia. Although it has been recorded in Belgium, Bulgaria, Greece, Hungary, Poland, Turkey and Ukraine, it has not established and is now considered absent from these countries. It has recently been reported in few fields in South-Eastern Spain (Gonza´lez et al., 2005). Apart from this record, there are few recent records of C. flaccumfaciens pv. flaccumfaciens in the EPPO region. No effective chemical methods are known against this disease; as C. flaccumfaciens pv. flaccumfaciens is a seed-borne bacterium, current control methods are based mainly on the use of healthy certified seeds. Economically, the most important host of C. flaccumfaciens pv. flaccumfaciens is P. vulgaris L., but the bacterium also attacks P. coccineus L., P. lunatus L. and P. mungo L.. Natural infections by C. flaccumfaciens pv. flaccumfaciens have been observed on Vigna spp. [V. angularis (Willd.) Ohiwi & Oashi, V. radiata (L.) R. Wilcz. and V. unguiculata (L.) Walsp. spp. unguiculata], on Glycine max (L.) Merr. and on Pisum sativum L. For more general information about C. flaccumfaciens pv. flaccumfaciens, see EPPO⁄CABI (1997). This diagnostic procedure for C. flaccumfaciens pv. flaccumfaciens describes extraction from plant material or seeds, presumptive diagnosis with rapid tests and simultaneous isolation of bacterial colonies, identification of C. flaccumfaciens pv. flaccumfaciens putative isolates and, where relevant, determination of pathogenicity. A flow diagram describing the procedure is given.