期刊
EUROPEAN JOURNAL OF PLANT PATHOLOGY
卷 126, 期 1, 页码 53-60出版社
SPRINGER
DOI: 10.1007/s10658-009-9523-2
关键词
Huanglongbing; Greening; Citrus; Bacteria; In vivo quantification
资金
- Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) [2005/00718-2]
- CNPq agency
The bacterium Candidatus Liberibacter asiaticus (CLas) is associated with huanglongbing (HLB) in citrus in many countries. Despite the fact that many characteristics of the disease are known, the rate of multiplication of the bacterium within an infected tree is still poorly understood. To study this feature, we used the quantitative Real-Time polymerase chain reaction (Q-PCR) assay to follow and to quantify the multiplication of CLas in grafted infected young sweet orange plants. The rate of infection by grafting reached 100% at 120 days post-inoculation (dpi) showing that grafting could easily transmit CLas. A well-adjusted linear regression equation describing the bacterial growth in planta was obtained independently with measurements taken using repeated sampling in the same plant or different plants through the analysed period. The bacterial population, measured as copy number (CN) of the 16S rDNA target gene g(-1) of tissue, increased 10,000 times from 10(3) at 30 dpi to approximately 10(8) CN at 240 dpi indicating that CLas multiplication was fastest in young citrus plants. We observed a direct relationship between the concentration of pathogen and the expression of symptoms. Yellowed leaves or shoots, are commonly the first observed symptom of HLB, and were present in trees with a low amount of bacteria (10(5) CN g(-1)). Blotchy mottle symptoms were observed in trees with 10(7) CN g(-1) of bacteria after 180 dpi. Buds taken from infected, but non-symptomatic branches were grafted on Rangpur lime and resulted in transmission rates ranging from 10 to 60%.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据