Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract only
Publication Acceptance Date: 5/14/2009
Publication Date: 8/1/2009
Citation: Deng, X., Chen, J., Xu, J., Guo, H., Pu, X., Cai, L., Li, H. 2009. Current Situation of Citrus Huanglongbing in Guangdong, P. R. China. American Phytopathological Society Annual Meeting. 99:S28. Interpretive Summary:
Technical Abstract: Guangdong Province is an important citrus production region in China. Citrus Huanglongbing (HLB, yellow shoot disease) was observed in Guangdong probably in the late 1800’s and the disease was first studied there. Since the 1990’s, citrus production in Guangdong has gradually shifted from the coastal Chaoshan and Pearl River delta plains, where HLB was endemic, to the mountainous / hillock North and West areas, where citrus production was limited and HLB was little known. As citrus production expanded, reports of HLB followed. To understand the HLB situation in Guangdong, we collected symptomatic citrus samples from 16 cultivars in 12 prefecture cities in 2007. PCR with primer set OI1/OI2c was used to detect “Candidatus Liberibacter asiaticus” for HLB confirmation. Among the total of 359 samples collected, 241 (67.1%) were positive for “Ca. L. asiaticus”, distributed in all 12 cities. Of particular importance is the confirmation of HLB in a mandarin cultivar “Shatangjie”, which currently occupies two thirds of the citrus planting acreage in Guangdong. We also identified HLB in the less popular cultivars “Mashuijie” and “Cuntianjie” which have high potential for future citrus production. Our data indicated that affected budwood probably played a key role in the current spread of HLB. To avoid future HLB outbreaks, strict regulation of propagation materials should be exercised along with optimal orchard management.