Location: Foreign Disease-Weed Science
Title: Preliminary evidence for mixed populations of Ca. Liberibacter species in Huanglongbing infections Authors
|Wilson, Chantel -|
Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: March 17, 2009
Publication Date: June 1, 2009
Citation: Postnikova, E.N., Stone, A.L., Wilson, C.M., Sherman, D.J., Sechler, A.J., Schuenzel, E., Schaad, N.W., Schneider, W.L., Damsteegt, V.D. 2009. Preliminary evidence for mixed populations of Ca. Liberibacter species in Huanglongbing infections. Phytopathology. 99:S205. Technical Abstract: Huanglongbing (HLB) is the most serious insect-transmitted disease of citrus in the world. Originally found only in Africa and Asia, it was discovered in Brazil and Florida in 2004 and 2005, respectively. Three Candidatus Liberibacter species, Ca. L. asiaticus (Las), Ca. L. africanus (Laf), and Ca. L. americanus (Lam) have been identified as causal agents. DNA was extracted and the ITS region was cloned from 29 different HLB samples from four continents (11 countries). Up to 50 clones per sample were sequenced. In 84 clones from seven single HLB samples from China, Indonesia, Japan, Philippines, Taiwan, Thailand, and Vietnam only Las was found. A single sample from India contained 3 Laf and 24 Las clones. All 87 clones of three samples from South Africa were identified as Laf. In 168 clones of 13 samples from Brazil, 124 were identified as Las, 30 were identified as Laf, and 14 were identified as Lam. Single clones from India and Taiwan appeared to be recombinants of Las and Laf. Seventy-one of 72 clones from two samples from Florida were Las, with the lone exception being a Laf clone. These results demonstrate that multiple Liberibacter species can coexist in a single plant.