Citrus huanglongbing（HLB） has become a major disease and limiting factor of production in citrus areas that have become infected. The destruction to the affected citrus industries has resulted in a tremendous increa...Citrus huanglongbing（HLB） has become a major disease and limiting factor of production in citrus areas that have become infected. The destruction to the affected citrus industries has resulted in a tremendous increase to support research that in return has resulted in significant information on both applied and basic knowledge concerning this important disease to the global citrus industry. Recent research indicates the relationship between citrus and the causal agent of HLB is shaped by multiple elements, in which host defense responses may also play an important role. This review is intended to provide an overview of the importance of HLB to a wider audience of plant biologists. Recent advances on host-pathogen interactions, population genetics and vectoring of the causal agent are discussed.展开更多
The Asiatic citrus psyllid （Diaphorina cirri Kuwayama [Hemiptera： Sternorrhyncha： Psyllidae] is a vector ofhuanglongbing （citrus greening）, a devastating disease of citrus caused by phloem-limited bacteria. Growi...The Asiatic citrus psyllid （Diaphorina cirri Kuwayama [Hemiptera： Sternorrhyncha： Psyllidae] is a vector ofhuanglongbing （citrus greening）, a devastating disease of citrus caused by phloem-limited bacteria. Growing guava （Psidium guajava） as an intercrop appears to be a successful means of reducing psyllid numbers within citrus orchards; however, the mechanism by which such a reduction is achieved is unknown. To determine the repellent effect of guava leaf and factors attributed to this activity, responses of adult psyllids to guava leaf and its odor were evaluated in cage tests and Y-tube olfactometer test. The results showed that guava leaf possessed a repellent effect against the adult citrus psyllids. Fewer psyllids were found on citrus leaves in the presence of guava foliage than in its absence. Young and old guava leaf showed equal repellent activity. By covering the guava shoots with net cloth, it was revealed that the repellent effect of guava leaf against adult psyllids on citrus was attributed to the volatile compounds, rather than physical factors. The olfactometer response of adult psyllids to guava leaf odor was dosage-dependent. Between guava odor and control, only 35.00%, 25.00% and 16.25% of the psyllids moved toward guava odor when presented with 5.0, 10.0 and 15.0 g of guava shoots, respectively. The olfactometer experiments also showed that both male and female psyllids responded similarly to the guava leaf odor.展开更多
In order to reveal the epidemic regularity of Huanglongbing （HLB） in different management approaches, different citrus production areas were selected between 2002 and 2012 to compare epidemic regularity of different...In order to reveal the epidemic regularity of Huanglongbing （HLB） in different management approaches, different citrus production areas were selected between 2002 and 2012 to compare epidemic regularity of different types and control effects of different management approaches with plant incidence rate. All survey data in 11 years were used to build a mathematical model, and epidemic evolution and control effects were quantitatively analyzed. The results indicated that diffusion and prevalence of HLB generally increased linearly. In naturally growing citrus orchards without artificial control, the annual diseased plant rate was 11.11%, and the epidemic diffusion model was y1 = 12. 24x - 1.382 8 （ n =9, r =0. 976 9 ＊ ＊ ）. Under general prevention and control conditions, the annual diseased plant rate was 4.69%, the epidemic diffusion model was Y2 = 5. 449 8x - 1.603 5 （ n = 11, r =0. 974 9 ＊ ＊ ）, and the control effect was 43.93% （22.93% - 55.04% ）. In citrus orchards with integrated prevention and control, the epidemic diffusion model was Y3 = 0. 366 3x - 0. 342 2 （ n = 11, r = 0. 989 8 ＊ ＊ ）, the control effect was 96.15% （94.95% -97.40% ）, and the annual diseased plant rate was 0.31%. Thus, HLB is preventable and controllable as long as integrated prevention and control work is implemented well.展开更多
为了探索研究柑橘木虱Diaphorina citri与柑橘黄龙病(Huanglongbing,HLB)病原菌的相互作用蛋白,本研究运用RNA转录中5'末端转换机制(Switching Mechanism at 5'End of the RNA Transcript,SMART)技术构建了柑橘木虱的酵母双杂交...为了探索研究柑橘木虱Diaphorina citri与柑橘黄龙病(Huanglongbing,HLB)病原菌的相互作用蛋白,本研究运用RNA转录中5'末端转换机制(Switching Mechanism at 5'End of the RNA Transcript,SMART)技术构建了柑橘木虱的酵母双杂交cDNA文库。以实验室饲养的柑橘木虱为材料,提取总RNA,经反转录后合成ds cDNA,两端添加同源重组序列,并用层析柱纯化;ds cDNA与文库质粒pGADT7-Rec在酵母Y187感受态细胞内发生同源重组,柑橘木虱cDNA重组到文库质粒上,完成酵母双杂交cDNA文库的构建。结果表明,文库容量达到106,扩增文库滴度为2.23×107cfu/mL,cDNA插入片段的平均长度大于750bp,达到试剂盒建库要求。另外,我们利用构建的酵母双杂交文库,以HLB病原菌Candidatus Liberibacter asiaticus(CLas)的两个膜蛋白ORF420和ORF3420作为诱饵进行筛选试验,但是并没有得到阳性克隆。柑橘木虱酵母cDNA文库的构建为开展柑橘木虱与柑橘黄龙病病原菌互作机制的研究奠定了基础。展开更多
基金the United States citrus industry and various funding agencies for their commitment and continued support for HLB research
文摘Citrus huanglongbing（HLB） has become a major disease and limiting factor of production in citrus areas that have become infected. The destruction to the affected citrus industries has resulted in a tremendous increase to support research that in return has resulted in significant information on both applied and basic knowledge concerning this important disease to the global citrus industry. Recent research indicates the relationship between citrus and the causal agent of HLB is shaped by multiple elements, in which host defense responses may also play an important role. This review is intended to provide an overview of the importance of HLB to a wider audience of plant biologists. Recent advances on host-pathogen interactions, population genetics and vectoring of the causal agent are discussed.
基金Our research was supported by special funds from the National Science Foundation of China （30471169）, the President＇s Foundation of South China Agricultural University （2007G003）, and the Department of Education, Science and Training of the Commonwealth of Australia （CH060068）. We thank Dr. Yi-Jing Cen and Mr. Ke- Cheng Huang for their kind cooperation during the study.
文摘The Asiatic citrus psyllid （Diaphorina cirri Kuwayama [Hemiptera： Sternorrhyncha： Psyllidae] is a vector ofhuanglongbing （citrus greening）, a devastating disease of citrus caused by phloem-limited bacteria. Growing guava （Psidium guajava） as an intercrop appears to be a successful means of reducing psyllid numbers within citrus orchards; however, the mechanism by which such a reduction is achieved is unknown. To determine the repellent effect of guava leaf and factors attributed to this activity, responses of adult psyllids to guava leaf and its odor were evaluated in cage tests and Y-tube olfactometer test. The results showed that guava leaf possessed a repellent effect against the adult citrus psyllids. Fewer psyllids were found on citrus leaves in the presence of guava foliage than in its absence. Young and old guava leaf showed equal repellent activity. By covering the guava shoots with net cloth, it was revealed that the repellent effect of guava leaf against adult psyllids on citrus was attributed to the volatile compounds, rather than physical factors. The olfactometer response of adult psyllids to guava leaf odor was dosage-dependent. Between guava odor and control, only 35.00%, 25.00% and 16.25% of the psyllids moved toward guava odor when presented with 5.0, 10.0 and 15.0 g of guava shoots, respectively. The olfactometer experiments also showed that both male and female psyllids responded similarly to the guava leaf odor.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest "Research and Demonstration of Comprehensive Prevention and Control Technology against Huanglongbing and Canker"(201003067)
文摘In order to reveal the epidemic regularity of Huanglongbing （HLB） in different management approaches, different citrus production areas were selected between 2002 and 2012 to compare epidemic regularity of different types and control effects of different management approaches with plant incidence rate. All survey data in 11 years were used to build a mathematical model, and epidemic evolution and control effects were quantitatively analyzed. The results indicated that diffusion and prevalence of HLB generally increased linearly. In naturally growing citrus orchards without artificial control, the annual diseased plant rate was 11.11%, and the epidemic diffusion model was y1 = 12. 24x - 1.382 8 （ n =9, r =0. 976 9 ＊ ＊ ）. Under general prevention and control conditions, the annual diseased plant rate was 4.69%, the epidemic diffusion model was Y2 = 5. 449 8x - 1.603 5 （ n = 11, r =0. 974 9 ＊ ＊ ）, and the control effect was 43.93% （22.93% - 55.04% ）. In citrus orchards with integrated prevention and control, the epidemic diffusion model was Y3 = 0. 366 3x - 0. 342 2 （ n = 11, r = 0. 989 8 ＊ ＊ ）, the control effect was 96.15% （94.95% -97.40% ）, and the annual diseased plant rate was 0.31%. Thus, HLB is preventable and controllable as long as integrated prevention and control work is implemented well.
文摘为了探索研究柑橘木虱Diaphorina citri与柑橘黄龙病(Huanglongbing,HLB)病原菌的相互作用蛋白,本研究运用RNA转录中5'末端转换机制(Switching Mechanism at 5'End of the RNA Transcript,SMART)技术构建了柑橘木虱的酵母双杂交cDNA文库。以实验室饲养的柑橘木虱为材料,提取总RNA,经反转录后合成ds cDNA,两端添加同源重组序列,并用层析柱纯化;ds cDNA与文库质粒pGADT7-Rec在酵母Y187感受态细胞内发生同源重组,柑橘木虱cDNA重组到文库质粒上,完成酵母双杂交cDNA文库的构建。结果表明,文库容量达到106,扩增文库滴度为2.23×107cfu/mL,cDNA插入片段的平均长度大于750bp,达到试剂盒建库要求。另外,我们利用构建的酵母双杂交文库,以HLB病原菌Candidatus Liberibacter asiaticus(CLas)的两个膜蛋白ORF420和ORF3420作为诱饵进行筛选试验,但是并没有得到阳性克隆。柑橘木虱酵母cDNA文库的构建为开展柑橘木虱与柑橘黄龙病病原菌互作机制的研究奠定了基础。
