Shepherd's purse seeds were collected from winter wheat fields and road sides in Hebei Province,China.Their sensitivities to tribenuron-methyl were evaluated in a whole plant dose response assay in the greenhouse.Res...Shepherd's purse seeds were collected from winter wheat fields and road sides in Hebei Province,China.Their sensitivities to tribenuron-methyl were evaluated in a whole plant dose response assay in the greenhouse.Results revealed that HB-1,HB-2,HB-3,HB-4,HB-6,HB-7,HB-17,HB-18,HB-19,HB-20,HB-21,and HB-22 populations were susceptible to tribenuron-methyl characterised by very low GR50 values of about 0.10 g a.i.ha-1.On the other hand,populations HB-15 and HB-16 had moderate resistance to tribenuron-methyl with resistance indices (RI) ranging from 10-100 folds,whilst populations HB-5,HB-8,HB-9,HB-10,HB-11,HB-12,HB-13,and HB-14 expressed high level of resistance to tribenuron-methyl with resistance indices over 100.The proportion of moderate resistance level was about 9.09%,and that of high resistance was about 36.36%.展开更多
Stem lignin content(SLC) in common wheat(Triticum aestivum L.) contributes to lodging resistance. Caffeic acid 3-O-methyltransferase(COMT) is a key enzyme involved in lignin biosynthesis. Characterization of TaCOMT ge...Stem lignin content(SLC) in common wheat(Triticum aestivum L.) contributes to lodging resistance. Caffeic acid 3-O-methyltransferase(COMT) is a key enzyme involved in lignin biosynthesis. Characterization of TaCOMT genes and development of gene-specific markers could enable marker-assisted selection in wheat breeding. In the present study, the full-length genomic DNA(gDNA) sequences of TaCOMT genes located on chromosomes 3 A, 3 B, and 3 D were cloned by homologous cloning. Two allelic variants, TaCOMT-3 Ba and TaCOMT-3 Bb, were identified and differed by a 222-bp insertion/deletion(InDel) in the 3′-untranslated region(3′-UTR). A co-dominant gene-specific marker based on this InDel was developed and designated as Ta COMT-3 BM. A total of 157 wheat cultivars and advanced lines grown in four environments were used to validate the associations between allelic patterns and SLC. The SLC of cultivars with TaCOMT-3 Ba was significantly(P<0.01) higher than that of those with TaCOMT-3 Bb, and the marker TaCOMT-3 BM could be effectively used in wheat breeding.展开更多
After trace Sm^3+ ions and Gd^3+ ions doping, the emission intensity of red phosphors Y2O2S: Eu^3 + was enhanced and the voltage character (relation between emission intensity and excitation voltage) was improve...After trace Sm^3+ ions and Gd^3+ ions doping, the emission intensity of red phosphors Y2O2S: Eu^3 + was enhanced and the voltage character (relation between emission intensity and excitation voltage) was improved while the other properties of physics and chemistry were not changed. The origins of enhancement and improvement are discussed. Probably the distortion and the defect of crystals are decreased by the substitution of Gd^3+ for Y^3+ instead of Eu^3+ for Y^3+ , and thus the Eu^3+ crystal field is improved, and radiationless process and energy loss resulted from crystal defect are weakened, which leads to increased luminescence intensity and voltage character improvement. The overlapping fluorescent spectra of Y2O2S: Sm^3+ emission and Y2O2S:Eu^3+ excitation as well as Eu^3 + excitation spectra transitions spectra lead to energy transfer from Sm^3 + sensitization of Sm^3+ ions fectively. containing Sm^3+ excitation the possibility of resonance ions to Eu^3+ ions, and the to Eu^3+ ions is achieved effectively.展开更多
The melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is a highly polyphagous sap sucking pest on wide varieties of crops including cotton and vegetables. It is a notorious vector of many plant viruses that a...The melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is a highly polyphagous sap sucking pest on wide varieties of crops including cotton and vegetables. It is a notorious vector of many plant viruses that are persistently and non-persistently transmitted. In nature, aphids are regulated by their natural enemies. However, chemical control remains a major management tool even though resistance to insecticides has been documented worldwide. A better understanding of mechanisms by which insecticide resistance occurs and its early detection is desirable to develop effective management strategies. The present investigation was conducted to study the development of resistance to an organophosphate (OP) compound-dimethoate, identify biochemical mechanism(s) involved in resistance and study cross-resistance to imidacloprid in laboratory selected A. gossypii strains in comparison to susceptible strains. Bioassay studies revealed that the LC50 values increased dramatically with dimethoate selection in resistant strains and the resistance ratio (RR) was 270-, 243- and 210-fold greater than that of the susceptible strains by 30th generation. Further, biochemical assays revealed enhanced activities of carboxylesterases (CarE), glutathione S-transferases (GSTs) and cytochrome P450-mediated p-Nitroanisole O-demethylase (PNOD) in resistant strains supporting their role in dimethoate detoxification. This study thus revealed that enhanced activity of detoxifying enzymes viz., CarE, GSTs and PNODs is one of the mechanisms underlying dimethoate resistance in A. gossypii collected from South India. Interestingly, the possibility of negatively correlated cross-resistance to imidacloprid was identified in three OP- resistant strains exhibiting 2.97-, 2.56- and 3.76-fold sensitivity to imidacloprid (a novel neonicotinoid). This indicated that the latter was less affected by the resistance mechanism(s) present.展开更多
The melon aphid, <i>Aphis gossypii</i> Glover (Hemiptera: Aphididae), is a highly polyphagous sap sucking pest on wide varieties of crops including cotton and vegetables. It is a notorious vector of many p...The melon aphid, <i>Aphis gossypii</i> Glover (Hemiptera: Aphididae), is a highly polyphagous sap sucking pest on wide varieties of crops including cotton and vegetables. It is a notorious vector of many plant viruses that are persistently and non-persistently transmitted. In nature, aphids are regulated by their natural enemies. However, chemical control remains a major management tool even though resistance to insecticides has been documented worldwide. A better understanding of mechanisms by which insecticide resistance occurs and its early detection is desirable to develop effective management strategies. The present investigation was conducted to study the development of resistance to an organophosphate (OP) compound-dimethoate, identify biochemical mechanism(s) involved in resistance and study cross-resistance to imidacloprid in laboratory selected <i>A. gossypii</i> strains in comparison to susceptible strains. Bioassay studies revealed that the LC50 values increased dramatically with dimethoate selection in resistant strains and the resistance ratio (RR) was 270-, 243- and 210-fold greater than that of the susceptible strains by 30th generation. Further, biochemical assays revealed enhanced activities of carboxylesterases (CarE), glutathione S-transferases (GSTs) and cytochrome P450-mediated <i>p</i>-Nitroanisole <i>O</i>-demethylase (PNOD) in resistant strains supporting their role in dimethoate detoxification. This study thus revealed that enhanced activity of detoxifying enzymes <i>viz</i>., CarE, GSTs and PNODs is one of the mechanisms underlying dimethoate resistance in <i>A. gossypii</i> collected from South India. Interestingly, the possibility of negatively correlated cross-resistance to imidacloprid was identified in three OP- resistant strains exhibiting 2.97-, 2.56- and 3.76-fold sensitivity to imidacloprid (a novel neonicotinoid). This indicated that the latter was less affected by the resistance mechanism(s) present.展开更多
基金supported by the State Key Laboratory for Biology of Plant Diseases and Insect Pests,Institute of Plant Protection (IPP),Chinese Academy of Agricultural Sciences,China (SKL2010OP15)the National Natural Science Foundation of China (31000856)
文摘Shepherd's purse seeds were collected from winter wheat fields and road sides in Hebei Province,China.Their sensitivities to tribenuron-methyl were evaluated in a whole plant dose response assay in the greenhouse.Results revealed that HB-1,HB-2,HB-3,HB-4,HB-6,HB-7,HB-17,HB-18,HB-19,HB-20,HB-21,and HB-22 populations were susceptible to tribenuron-methyl characterised by very low GR50 values of about 0.10 g a.i.ha-1.On the other hand,populations HB-15 and HB-16 had moderate resistance to tribenuron-methyl with resistance indices (RI) ranging from 10-100 folds,whilst populations HB-5,HB-8,HB-9,HB-10,HB-11,HB-12,HB-13,and HB-14 expressed high level of resistance to tribenuron-methyl with resistance indices over 100.The proportion of moderate resistance level was about 9.09%,and that of high resistance was about 36.36%.
基金supported by the National Natural Science Foundation of China(31161140346 and 31461143021)the Beijing Municipal Science and Technology Project,China(D151100004415003)+1 种基金the National Key Technology R&D Program of China(2014BAD01B05)the earmarked fund for China Agriculture Research System(CARS-3-1-3)
文摘Stem lignin content(SLC) in common wheat(Triticum aestivum L.) contributes to lodging resistance. Caffeic acid 3-O-methyltransferase(COMT) is a key enzyme involved in lignin biosynthesis. Characterization of TaCOMT genes and development of gene-specific markers could enable marker-assisted selection in wheat breeding. In the present study, the full-length genomic DNA(gDNA) sequences of TaCOMT genes located on chromosomes 3 A, 3 B, and 3 D were cloned by homologous cloning. Two allelic variants, TaCOMT-3 Ba and TaCOMT-3 Bb, were identified and differed by a 222-bp insertion/deletion(InDel) in the 3′-untranslated region(3′-UTR). A co-dominant gene-specific marker based on this InDel was developed and designated as Ta COMT-3 BM. A total of 157 wheat cultivars and advanced lines grown in four environments were used to validate the associations between allelic patterns and SLC. The SLC of cultivars with TaCOMT-3 Ba was significantly(P<0.01) higher than that of those with TaCOMT-3 Bb, and the marker TaCOMT-3 BM could be effectively used in wheat breeding.
文摘After trace Sm^3+ ions and Gd^3+ ions doping, the emission intensity of red phosphors Y2O2S: Eu^3 + was enhanced and the voltage character (relation between emission intensity and excitation voltage) was improved while the other properties of physics and chemistry were not changed. The origins of enhancement and improvement are discussed. Probably the distortion and the defect of crystals are decreased by the substitution of Gd^3+ for Y^3+ instead of Eu^3+ for Y^3+ , and thus the Eu^3+ crystal field is improved, and radiationless process and energy loss resulted from crystal defect are weakened, which leads to increased luminescence intensity and voltage character improvement. The overlapping fluorescent spectra of Y2O2S: Sm^3+ emission and Y2O2S:Eu^3+ excitation as well as Eu^3 + excitation spectra transitions spectra lead to energy transfer from Sm^3 + sensitization of Sm^3+ ions fectively. containing Sm^3+ excitation the possibility of resonance ions to Eu^3+ ions, and the to Eu^3+ ions is achieved effectively.
文摘The melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is a highly polyphagous sap sucking pest on wide varieties of crops including cotton and vegetables. It is a notorious vector of many plant viruses that are persistently and non-persistently transmitted. In nature, aphids are regulated by their natural enemies. However, chemical control remains a major management tool even though resistance to insecticides has been documented worldwide. A better understanding of mechanisms by which insecticide resistance occurs and its early detection is desirable to develop effective management strategies. The present investigation was conducted to study the development of resistance to an organophosphate (OP) compound-dimethoate, identify biochemical mechanism(s) involved in resistance and study cross-resistance to imidacloprid in laboratory selected A. gossypii strains in comparison to susceptible strains. Bioassay studies revealed that the LC50 values increased dramatically with dimethoate selection in resistant strains and the resistance ratio (RR) was 270-, 243- and 210-fold greater than that of the susceptible strains by 30th generation. Further, biochemical assays revealed enhanced activities of carboxylesterases (CarE), glutathione S-transferases (GSTs) and cytochrome P450-mediated p-Nitroanisole O-demethylase (PNOD) in resistant strains supporting their role in dimethoate detoxification. This study thus revealed that enhanced activity of detoxifying enzymes viz., CarE, GSTs and PNODs is one of the mechanisms underlying dimethoate resistance in A. gossypii collected from South India. Interestingly, the possibility of negatively correlated cross-resistance to imidacloprid was identified in three OP- resistant strains exhibiting 2.97-, 2.56- and 3.76-fold sensitivity to imidacloprid (a novel neonicotinoid). This indicated that the latter was less affected by the resistance mechanism(s) present.
文摘The melon aphid, <i>Aphis gossypii</i> Glover (Hemiptera: Aphididae), is a highly polyphagous sap sucking pest on wide varieties of crops including cotton and vegetables. It is a notorious vector of many plant viruses that are persistently and non-persistently transmitted. In nature, aphids are regulated by their natural enemies. However, chemical control remains a major management tool even though resistance to insecticides has been documented worldwide. A better understanding of mechanisms by which insecticide resistance occurs and its early detection is desirable to develop effective management strategies. The present investigation was conducted to study the development of resistance to an organophosphate (OP) compound-dimethoate, identify biochemical mechanism(s) involved in resistance and study cross-resistance to imidacloprid in laboratory selected <i>A. gossypii</i> strains in comparison to susceptible strains. Bioassay studies revealed that the LC50 values increased dramatically with dimethoate selection in resistant strains and the resistance ratio (RR) was 270-, 243- and 210-fold greater than that of the susceptible strains by 30th generation. Further, biochemical assays revealed enhanced activities of carboxylesterases (CarE), glutathione S-transferases (GSTs) and cytochrome P450-mediated <i>p</i>-Nitroanisole <i>O</i>-demethylase (PNOD) in resistant strains supporting their role in dimethoate detoxification. This study thus revealed that enhanced activity of detoxifying enzymes <i>viz</i>., CarE, GSTs and PNODs is one of the mechanisms underlying dimethoate resistance in <i>A. gossypii</i> collected from South India. Interestingly, the possibility of negatively correlated cross-resistance to imidacloprid was identified in three OP- resistant strains exhibiting 2.97-, 2.56- and 3.76-fold sensitivity to imidacloprid (a novel neonicotinoid). This indicated that the latter was less affected by the resistance mechanism(s) present.
文摘目的寻找能将氨基酸侧链的羟基、巯基与二元羧酸连接成酯的方法。方法分别以L 丝氨酸和L 半胱氨酸为起始物 ,采用叔丁氧羰基、苄酯或二苯甲酯形式保护 ,分别与丁二酸单苄酯、草酸单苄酯、丁二酸单叔丁酯缩合成酯 ,合成了 3个未见文献报道的化合物O (4 苄氧丁二酰基 ) N 叔丁氧羰基 L 丝氨酸苄酯 (4 )、O (2 苄氧草酰基 ) N 叔丁氧羰基 L 丝氨酸苄酯 (8)、S (4 叔丁氧丁二酰基 ) N 叔丁氧羰基 L 半胱氨酸二苯甲酯 (12 )。化合物 4经氢解合成未见文献报道的化合物O 丁二酰基 N 叔丁氧羰基 L 丝氨酸 (5 )。化合物 5经酸解得到O 丁二酰基 L 丝氨酸(6)。结果与结论目标化合物的结构经光谱确证。通过这种方法二元羧酸能与氨基酸的羟基。