First report of bacterial leaf spot of poinsettia in China
In China, unusual symptoms were observed on poinsettia (Euphorbia pulcherrima cv. Fu-xing) at a flower nursery in the Zhejiang province in October 2003. Small, water-soaked lesions scattered across the leaf surface, rapidly enlarged becoming yellow-to-tan. Spots often coalesced to form large, necrotic areas surrounded by a yellow halo, which at times extended into the lateral veins causing a blighted appearance. No spots were observed on the coloured bracts. A bacterium was isolated from symptomatic leaves and bacterial exudates often formed on lesions, especially on the lower leaf surface. The bacterium was identified as Xanthomonas campestris pv. poinsettiicola using the traditional classification of xanthomonads, but data was not sufficient to allocate it to X. axonopodis pv. poinsettiicola (EPPO Alert List) or other species using the new classification proposed by Vauterin et al. (1995).
Sources
Li B, Xie GL, Swings J (2005) First report of leaf spot caused by Xanthomonas campestris on poinsettia in China. New Disease Reports, Volume 11: February 2005 - July 2005. http://www.bspp.org.uk/ndr/july2005/2005-28.asp
Vauterin L, Hoste B, Kersters K, Swings J (1995) Reclassification of Xanthomonas.
International Journal of Systematic Bacteriology 45, 472-489.