Micrometeorological and microplot experiments were conducted in the field of freshly harvested green cane in Queensland, Australia. Results showed that high ammonia loss of fertilizer N could occur under relatively dr...Micrometeorological and microplot experiments were conducted in the field of freshly harvested green cane in Queensland, Australia. Results showed that high ammonia loss of fertilizer N could occur under relatively dry conditions when urea or commercial product of mixture of urea and muriate of potash were applied to the surface of sugarcane trash. The moisture content in the trash and the pH of fertilizer were two important factors controlling the processes of urea hydrolysis and ammonia volatilization. Most of the N in the soil was transformed to the nitrate+ nitrite from after 70 days of fertilizer application. No significant leaching was found. Urea-free N fertilizers had higher N recoveries compared to urea-containing fertilizers. .展开更多
GPV is a Chinese serotype isolate of barley yellow dwarf virus (BYDV) that has no reactionwith antiserum of MAV, PAV, SGV, RPV and RMV. The sequence of the coat protein (CP) of GPV isolate of BYDV was identified and i...GPV is a Chinese serotype isolate of barley yellow dwarf virus (BYDV) that has no reactionwith antiserum of MAV, PAV, SGV, RPV and RMV. The sequence of the coat protein (CP) of GPV isolate of BYDV was identified and its amino acid sequence was deduced. The coding region for the putative GPV CP is 603 bases nucleotides and encodes a Mr 22218 (22 ku) protein. The same as MAV, PAV and RPV, GPV contained a second ORF within the coat protein coding region. This protein of 17024 Mr (17 ku) is thought to correspond to the Virion protein genome linked (Vpg). Sequence comparisons of the CP coding region between the GPV isolate of BYDV and other isolates of BYDV have been done. The nucleotide and ammo acid sequence homology of GPV has a greater identity to the sequence of RPV than those of PAV and MAV. The GPV CP sequence shared 83.7% of nucleotide similarity and 77.5% of deduced amino add similarity, whereas that of the PAV and MAV shared 56.9%. 53.2% and 44.1%. 43.8% respectively. According to BYDV-GPV CP sequence, two primers were designed. The cDNA of CP was produced by RT-PCR. Full-length cDNA of CP was inserted into plasmid to construct expression plasmids named pPPI1. pPPI2 and pPPI5 based on different promoters. The recombinant plasmids were identified by using α-32P-dATP labelled CP probe. α-32P-ATP labelled GPV RNA probe and sequencing to confirm real GPV CP gene cDNA in plasmids.展开更多
We report six different field trials testing the efficacy of Metarhizium anisopliae,an entomopathogenic fungus,against varroa mites in honey bee hives.Varroa mites are parasitic on honey bees and cause serious damage ...We report six different field trials testing the efficacy of Metarhizium anisopliae,an entomopathogenic fungus,against varroa mites in honey bee hives.Varroa mites are parasitic on honey bees and cause serious damage to Apis mellifera colonies.Several control methods are available for varroa mites,none are very effective,so new,more effective methods are being sought.Varroa has previously been shown to be highly susceptible to M.anisopliae infections,and in our first two field trials,we found some efficacy from spore applications.However,in subsequent field trials,we were not able to obtain any varroa control,despite attempting several different application methods,two different strains of the fungus,and testing in different climates and during different phenological states of the honey bee colony.We conclude that microbial control of varroa using fungi is not likely to be effective unless some way is found to prolong the survival of the spores(or other infective units)in the hive environment.展开更多
Barley yellow dwarf virus (BYDV) is one of the most serious wheat diseases in China. So far no resistance has been described in common wheat. A certain level of BYDV resistance was found in thirteen Triticeae species....Barley yellow dwarf virus (BYDV) is one of the most serious wheat diseases in China. So far no resistance has been described in common wheat. A certain level of BYDV resistance was found in thirteen Triticeae species. Thinopyrum intermedium, two octoploids derived from TH. intermedium/wheat, Zhong 4 awnless and TAF46, and one disomic addition line, L1 derived from TAF46, showed good resistance to BYDV by enzyme linked immunosorbent assay (ELISA). Two wheat/TA. intermedium translocation lines, CPI 119880 and CPI 119899, showing good BYDV resistance were developed from L1 by using both CSph mutant and tissue culture. It is found that their BYDV resistance was controlled by a single dominant gene. Two cDNA probes pEleAcc3 and pPJN8 (E1-T1) were screened for detecting Th. intermedium DNA in wheat background. A specific band for the DNA of Th. intermedium and its derivatives was found in Southern hybridization. It is also possible to determine the size of the alien segment by comparing the relative density of the specific band. Therefore, this can be used as a marker to identify the BYDV resistance in wheat breeding program.展开更多
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 largest superfamily Entomobryoidea is one of the key groups in Collembola.However,incorrect recognition of chaetotaxic homology within Entomobryoidea severely impedes the accurate species comparison of adults and ...The largest superfamily Entomobryoidea is one of the key groups in Collembola.However,incorrect recognition of chaetotaxic homology within Entomobryoidea severely impedes the accurate species comparison of adults and phylogenetic reconstruction.Traditional classification of the superfamily at suprageneric level is disputable in the light of recent advances.Transformational homology of tergal chaetotaxy was traced and revised based on 38 species of first instar and partial early instars.Morphological phylogenetic reconstructions were reconstructed mainly relying on first instar characters using both parsimony and likelihoodbased algorithms.Outgroup selection and several rogue taxa impacted on resolution and support of otherwise well-supported clades.Integrating published molecular phylogeny,a revised classification of three families and nine subfamilies was presented:Orchesellidae,Entomobryidae and Paronellidae.Orchesellidae includes all basal taxa having a short fourth abdominal segment.Cyphoderidae and Microfalculidae taxa were sunk into Paronellidae.New Paronellidae was divided into two subfamilies:Paronellinae(Paronellini+Cyphoderini+Bromacanthini)and Salininae(Cremastocephalini+Callyntrurini).Microfalculidae(Microfalcula)was closer to Salina and Akabosia and thus transferred into Cremastocephalini.This study erected a new classification framework for Entomobryoidea based upon comprehensive phylogenies.Chaetotaxic homologization across a wide range provided a standardized,comparable,powerful tool for taxonomy.展开更多
Numerous disease states are characterized by ectopic expression of genes.Recent findings suggest that crosstalk between systems that regulate gene expression during animal development ensures responsiveness to environ...Numerous disease states are characterized by ectopic expression of genes.Recent findings suggest that crosstalk between systems that regulate gene expression during animal development ensures responsiveness to environmental cues.展开更多
文摘Micrometeorological and microplot experiments were conducted in the field of freshly harvested green cane in Queensland, Australia. Results showed that high ammonia loss of fertilizer N could occur under relatively dry conditions when urea or commercial product of mixture of urea and muriate of potash were applied to the surface of sugarcane trash. The moisture content in the trash and the pH of fertilizer were two important factors controlling the processes of urea hydrolysis and ammonia volatilization. Most of the N in the soil was transformed to the nitrate+ nitrite from after 70 days of fertilizer application. No significant leaching was found. Urea-free N fertilizers had higher N recoveries compared to urea-containing fertilizers. .
基金Project supported by the International Agriculture Research Center of Australia and 863 Biotechnology Project Foundation of China.
文摘GPV is a Chinese serotype isolate of barley yellow dwarf virus (BYDV) that has no reactionwith antiserum of MAV, PAV, SGV, RPV and RMV. The sequence of the coat protein (CP) of GPV isolate of BYDV was identified and its amino acid sequence was deduced. The coding region for the putative GPV CP is 603 bases nucleotides and encodes a Mr 22218 (22 ku) protein. The same as MAV, PAV and RPV, GPV contained a second ORF within the coat protein coding region. This protein of 17024 Mr (17 ku) is thought to correspond to the Virion protein genome linked (Vpg). Sequence comparisons of the CP coding region between the GPV isolate of BYDV and other isolates of BYDV have been done. The nucleotide and ammo acid sequence homology of GPV has a greater identity to the sequence of RPV than those of PAV and MAV. The GPV CP sequence shared 83.7% of nucleotide similarity and 77.5% of deduced amino add similarity, whereas that of the PAV and MAV shared 56.9%. 53.2% and 44.1%. 43.8% respectively. According to BYDV-GPV CP sequence, two primers were designed. The cDNA of CP was produced by RT-PCR. Full-length cDNA of CP was inserted into plasmid to construct expression plasmids named pPPI1. pPPI2 and pPPI5 based on different promoters. The recombinant plasmids were identified by using α-32P-dATP labelled CP probe. α-32P-ATP labelled GPV RNA probe and sequencing to confirm real GPV CP gene cDNA in plasmids.
文摘We report six different field trials testing the efficacy of Metarhizium anisopliae,an entomopathogenic fungus,against varroa mites in honey bee hives.Varroa mites are parasitic on honey bees and cause serious damage to Apis mellifera colonies.Several control methods are available for varroa mites,none are very effective,so new,more effective methods are being sought.Varroa has previously been shown to be highly susceptible to M.anisopliae infections,and in our first two field trials,we found some efficacy from spore applications.However,in subsequent field trials,we were not able to obtain any varroa control,despite attempting several different application methods,two different strains of the fungus,and testing in different climates and during different phenological states of the honey bee colony.We conclude that microbial control of varroa using fungi is not likely to be effective unless some way is found to prolong the survival of the spores(or other infective units)in the hive environment.
基金This research is supported by the Australian Centre for International Agricultural Research(Projects 8379 and 8813)by the National Science and Technology Committee of China on China's side.
文摘Barley yellow dwarf virus (BYDV) is one of the most serious wheat diseases in China. So far no resistance has been described in common wheat. A certain level of BYDV resistance was found in thirteen Triticeae species. Thinopyrum intermedium, two octoploids derived from TH. intermedium/wheat, Zhong 4 awnless and TAF46, and one disomic addition line, L1 derived from TAF46, showed good resistance to BYDV by enzyme linked immunosorbent assay (ELISA). Two wheat/TA. intermedium translocation lines, CPI 119880 and CPI 119899, showing good BYDV resistance were developed from L1 by using both CSph mutant and tissue culture. It is found that their BYDV resistance was controlled by a single dominant gene. Two cDNA probes pEleAcc3 and pPJN8 (E1-T1) were screened for detecting Th. intermedium DNA in wheat background. A specific band for the DNA of Th. intermedium and its derivatives was found in Southern hybridization. It is also possible to determine the size of the alien segment by comparing the relative density of the specific band. Therefore, this can be used as a marker to identify the BYDV resistance in wheat breeding program.
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supported by the National Natural Science Foundation of China(31772491,31970434) to Feng Zhang
文摘The largest superfamily Entomobryoidea is one of the key groups in Collembola.However,incorrect recognition of chaetotaxic homology within Entomobryoidea severely impedes the accurate species comparison of adults and phylogenetic reconstruction.Traditional classification of the superfamily at suprageneric level is disputable in the light of recent advances.Transformational homology of tergal chaetotaxy was traced and revised based on 38 species of first instar and partial early instars.Morphological phylogenetic reconstructions were reconstructed mainly relying on first instar characters using both parsimony and likelihoodbased algorithms.Outgroup selection and several rogue taxa impacted on resolution and support of otherwise well-supported clades.Integrating published molecular phylogeny,a revised classification of three families and nine subfamilies was presented:Orchesellidae,Entomobryidae and Paronellidae.Orchesellidae includes all basal taxa having a short fourth abdominal segment.Cyphoderidae and Microfalculidae taxa were sunk into Paronellidae.New Paronellidae was divided into two subfamilies:Paronellinae(Paronellini+Cyphoderini+Bromacanthini)and Salininae(Cremastocephalini+Callyntrurini).Microfalculidae(Microfalcula)was closer to Salina and Akabosia and thus transferred into Cremastocephalini.This study erected a new classification framework for Entomobryoidea based upon comprehensive phylogenies.Chaetotaxic homologization across a wide range provided a standardized,comparable,powerful tool for taxonomy.
文摘Numerous disease states are characterized by ectopic expression of genes.Recent findings suggest that crosstalk between systems that regulate gene expression during animal development ensures responsiveness to environmental cues.
