The strawberry crimp nematode(Aphelenchoides fragariae) is a serious pathogen of ornamental crops and a significant quarantine concern in approximately 50 countries and regions,including China.A nematode population be...The strawberry crimp nematode(Aphelenchoides fragariae) is a serious pathogen of ornamental crops and a significant quarantine concern in approximately 50 countries and regions,including China.A nematode population belonging to the genus Aphelenchoides was isolated from symptomatic leaves of fuchsia plants(Fuchsia×hybrida Hort.ex Sieb.& Voss.) in Chengdu,Sichuan Province,China.Morphological and morphometric characteristics were determined using light microscopy and scanning electron microscopy.Detailed examination revealed diagnostic features consistent with A.fragariae.Three ribosomal DNA(rDNA) regions,i.e.,partial small subunit(SSU) rRNA,D2-D3 expansion segments of the large subunit(LSU) rRNA,and the internal transcribed spacer(ITS),were amplified and sequenced.Bayesian phylogenetic analyses based on these sequences placed the isolate in a well-supported monophyletic clade with reference A.fragariae specimens,clearly separated from other Aphelenchoides species.Furthermore,host-suitability assays demonstrated that this nematode population not only infects and reproduces on Fuchsia×hybrida,but also on Fragaria ananassa and Pteris vittata,two known hosts of A.fragariae.Collectively,morphological,molecular,and host-range evidence confirm the identification of this nematode as A.fragariae.To our knowledge,this represents the first molecular and morphological confirmation of A.fragariae in China,and the first report of Fuchsia×hybrida as a natural host for this species.展开更多
The colour of the Hall effect thruster＇s plume is often light-green, and sometimes a fuchsia plume appears during experiments. Based on a spectrum and colour analysis, and a comparison with normal plumes, a conclusio...The colour of the Hall effect thruster＇s plume is often light-green, and sometimes a fuchsia plume appears during experiments. Based on a spectrum and colour analysis, and a comparison with normal plumes, a conclusion is made that the density of the Xe ions and the temperature of electrons are low when the plume appears fuchsia. In this condition, most of the components of the plume are Xe atoms, and the ionization rate of the propellant is low.展开更多
基金financially supported by the Shaanxi Innovation Team Project,China (2024RS-CXTD-73)the National Natural Science Foundation of China (31772136)。
文摘The strawberry crimp nematode(Aphelenchoides fragariae) is a serious pathogen of ornamental crops and a significant quarantine concern in approximately 50 countries and regions,including China.A nematode population belonging to the genus Aphelenchoides was isolated from symptomatic leaves of fuchsia plants(Fuchsia×hybrida Hort.ex Sieb.& Voss.) in Chengdu,Sichuan Province,China.Morphological and morphometric characteristics were determined using light microscopy and scanning electron microscopy.Detailed examination revealed diagnostic features consistent with A.fragariae.Three ribosomal DNA(rDNA) regions,i.e.,partial small subunit(SSU) rRNA,D2-D3 expansion segments of the large subunit(LSU) rRNA,and the internal transcribed spacer(ITS),were amplified and sequenced.Bayesian phylogenetic analyses based on these sequences placed the isolate in a well-supported monophyletic clade with reference A.fragariae specimens,clearly separated from other Aphelenchoides species.Furthermore,host-suitability assays demonstrated that this nematode population not only infects and reproduces on Fuchsia×hybrida,but also on Fragaria ananassa and Pteris vittata,two known hosts of A.fragariae.Collectively,morphological,molecular,and host-range evidence confirm the identification of this nematode as A.fragariae.To our knowledge,this represents the first molecular and morphological confirmation of A.fragariae in China,and the first report of Fuchsia×hybrida as a natural host for this species.
基金supported by the National Defence Foundation Research(No.K1403060719)
文摘The colour of the Hall effect thruster＇s plume is often light-green, and sometimes a fuchsia plume appears during experiments. Based on a spectrum and colour analysis, and a comparison with normal plumes, a conclusion is made that the density of the Xe ions and the temperature of electrons are low when the plume appears fuchsia. In this condition, most of the components of the plume are Xe atoms, and the ionization rate of the propellant is low.
