<div style="text-align:justify;"> <em>Citrus tristeza virus</em> (CTV) is an important citrus pathogen causing considerable economic loss to citrus production. Knowledge on genetic evolutio...<div style="text-align:justify;"> <em>Citrus tristeza virus</em> (CTV) is an important citrus pathogen causing considerable economic loss to citrus production. Knowledge on genetic evolutionary of the CTV population in China remains limited. In this study, 1439 samples were collected from nine citrus-producing areas of China. The coat protein (CP) genes of CTV were amplified by RT-PCR, and sequenced to analyze the genetic evolution. Analysis of the base composition showed an AU preference pattern, with the GC content was lower than AU content. Nine CTV populations were clustered into one clade in neighbor-joining (NJ) tree, indicative of a close phylogenetic relationship among the populations in China. Analysis of molecular variation (AMOVA) revealed that 77.72% genetic variations of CTV populations were observed among populations, with an <em>F</em><sub>ST</sub> value of 0.223. The values of <em>d<sub>N</sub>/d<sub>S</sub></em> and neutrality test of <em>CP</em> gene were ranged from 0.016 to 0.082 and -1.377 to 1.456, respectively, the results suggesting that all of nine CTV populations were relatively constantly maintained under purifying selection. Our study demonstrated the genetic characteristics and molecular evolution relationship of CTV populations in China, and provided a theoretical basis for scientific control of CTV. </div>展开更多
YILING,the largest district in Yichang City,Hubei Province,is noted for its non-metallic mines,tea planting,citrus fruit cultivation,and folk art.In recent years,Yiling's focus has been on urban-rural integration.Hum...YILING,the largest district in Yichang City,Hubei Province,is noted for its non-metallic mines,tea planting,citrus fruit cultivation,and folk art.In recent years,Yiling's focus has been on urban-rural integration.Human Development The strategies of Yiling District include inheriting traditional culture and ensuring sustained development.展开更多
文摘<div style="text-align:justify;"> <em>Citrus tristeza virus</em> (CTV) is an important citrus pathogen causing considerable economic loss to citrus production. Knowledge on genetic evolutionary of the CTV population in China remains limited. In this study, 1439 samples were collected from nine citrus-producing areas of China. The coat protein (CP) genes of CTV were amplified by RT-PCR, and sequenced to analyze the genetic evolution. Analysis of the base composition showed an AU preference pattern, with the GC content was lower than AU content. Nine CTV populations were clustered into one clade in neighbor-joining (NJ) tree, indicative of a close phylogenetic relationship among the populations in China. Analysis of molecular variation (AMOVA) revealed that 77.72% genetic variations of CTV populations were observed among populations, with an <em>F</em><sub>ST</sub> value of 0.223. The values of <em>d<sub>N</sub>/d<sub>S</sub></em> and neutrality test of <em>CP</em> gene were ranged from 0.016 to 0.082 and -1.377 to 1.456, respectively, the results suggesting that all of nine CTV populations were relatively constantly maintained under purifying selection. Our study demonstrated the genetic characteristics and molecular evolution relationship of CTV populations in China, and provided a theoretical basis for scientific control of CTV. </div>
文摘YILING,the largest district in Yichang City,Hubei Province,is noted for its non-metallic mines,tea planting,citrus fruit cultivation,and folk art.In recent years,Yiling's focus has been on urban-rural integration.Human Development The strategies of Yiling District include inheriting traditional culture and ensuring sustained development.