Phytophthora infestans control is a long-standing problem that has caused ongoing difficulties and brought limited success for over a century.Traditional methods,such as fungicides,have drawbacks including high cost,r...Phytophthora infestans control is a long-standing problem that has caused ongoing difficulties and brought limited success for over a century.Traditional methods,such as fungicides,have drawbacks including high cost,restrictions on organic farming,potential risks to the environment and human health,and the development of resistant strains.In this study,we employed cutting-edge computer-based techniques,including Quantitative Structure-Activity Relationship(QSAR)modeling and molecular docking simulations,to uncover new fungicidal compounds and gain insights into their specific mechanisms of action against P.infestans.QSAR modeling on the number of compounds tested as P.infestans inhibitors was performed using an interactive OCHEM web platform.The predictive ability of the developed classification models had a balanced accuracy(BA)of 77–85%for the training set and BA?89–93%for the validation external test set.During the in vitro testing against P.infestans,thirteen synthesized 2-oxoimidazolidine-4-sulfonamides demonstrated inhibition rates,ranging from 23.6%to 87.4%.The fungicidal potential of six of these fungicides ranged from 79.3%to 87.4%,which is comparable to the activity of known fungicides.Acute toxicity results using the well-known aquatic marker Daphnia magna showed that the most active sulfonamides 3d,3f,3h,3j,3k,and 3l,with LC_(50) values ranging from 13.7 to 52.9 mg/L,are low-toxicity compounds.The molecular docking results demonstrated a potential mechanism of the antifungal action of the studied 2-oxoimidazolidin-4-sulfonamide derivatives via the inhibition of fungal CYP51,a sterol biosynthesis enzyme.展开更多
Phytophthora capsici Leonian is a destructive pathogen that affects pepper production worldwide.Resistance breeding has been proposed as the most efficient and eco-friendly management strategy for controlling this pat...Phytophthora capsici Leonian is a destructive pathogen that affects pepper production worldwide.Resistance breeding has been proposed as the most efficient and eco-friendly management strategy for controlling this pathogen.This study aimed to characterize the genetic architecture of P.capsici resistance in pepper to support its resistance breeding.In this study,a panel of 220 accessions of Capsicum annuum were evaluated for resistance to P.capsici under controlled conditions.The panel was genotyped via genotyping-by-sequencing(GBS),and the resulting 955 772 high-quality variations were used for the population stratification analysis and the identification of chromosome regions associated with resistance against P.capsici.Strong association signals were detected mainly on chromosomes 5(CaRPc5.1) and 10(CaRPc10.1).The associated single nucleotide polymorphisms(SNPs) explained 5.61%-11.71% of the phenotypic variation.The 220 accessions were divided into four genetic clusters,including an ancestral cluster,a transition cluster,and two recently emerged clusters.P.capsici resistance of the four clusters unveiled compromised resistance to P.capsici during modern domestication,which was hypothesized to be a trade-off for desirable horticultural traits.Using bulked segregant analysis(BSA) and whole-genome resequencing(WGR),a major locus in an F_(4:5) population,derived from a cross between the P.capsici-resistant parent A204 and the susceptible parent A198,was mapped to a 1.81 Mb region on chromosome 10,which coincided with the CaRPc10.1 locus.This locus was further fine-mapped into a 32.36 kb region based on two derived F_(5:6) populations consisting of 2 713 individuals.The Capann59Chr10g029350 gene,a likely allelic variation of the Pur4 gene in this interval,was proposed as a strong candidate gene for Phytophthora capsisi resistance.Our results provide molecular perspectives into the P.capsici-resistance mechanism and molecular markers for the improvement of P.capsici resistance in pepper and pave the way for cloning the resistance gene underlying CaRPc10.1.展开更多
A complete cDNA of potato Phytophthora infestans-induced hypersensitive response-related protein gene (POTHR-1) was cloned using rapid amplification of cDNA ends (RACE) strategy according to a fragment sequence which ...A complete cDNA of potato Phytophthora infestans-induced hypersensitive response-related protein gene (POTHR-1) was cloned using rapid amplification of cDNA ends (RACE) strategy according to a fragment sequence which we had cloned using suppression subtractive hybridization (SSH) technique. The potato POTHR-1 gene encodes a protein of 225 amino acids, which shares 81% identity with tobacco hin1 gene-enoded protein (harpin-induced protein). Southern blot revealed that there are two to three copies of POTHR-1 in potato genome. The POTHR-1 gene expression in potato leaves showed that its transcripts accumulated remarkably in leaves after 36 h inoculation with P. infestans. Mechanical wounding and jasmonic acid (JA) could induce the POTHR-1 gene expression and osmotic stress just induce a slight accumulation of POTHR-1 gene mRNA, while salicylic acid (SA) had no detectable function on the induction accumulation of POTHR-1 gene transcripts. The potato POTHR-1 gene may preferentially associate with hypersensitive response (HR) or biotic cell death during interaction between host and pathogen.展开更多
[ Objective ] The paper was to screen bacterial strain with significant antagonistic effect against Phytophthora infestans, so as to provide basis for further development and utilization of antagonistic bacteria to in...[ Objective ] The paper was to screen bacterial strain with significant antagonistic effect against Phytophthora infestans, so as to provide basis for further development and utilization of antagonistic bacteria to inhibit P. infestans and control potato late bright. [ Method] Plate dual culture and filter paper method were used to determine the inhibition effect of strains in vivo, fermentation broth and bacterial liquid of 61 strains against P. infestans and the resistance-induction effect of SR13-2 strain. [ Result] The inhibition rate of 24 strains among 61 tested strains against mycelial growth of P. infestans was greater than 60%, and the inhibi- tion effect of HT-6 strain was the strongest with the inhibition rate of 89.92%. However, fermentation broth of all tested strains had no significant inhibition effect against P. infestans, while the inhibition effect of bacterial liquid of most strains was significantly higher than strain in vivo; the inhibition effect of $34-1 strain was the strongest with inhibition rate of 91.50%. The bacterial liquid of SR13-2 strain was found to have significant resistance-induction effect with protective rate of 60%. [ Conclusion] The inhibition effect of strains in vivo and fermentation broth of antagonistic strains S34-1 and SR13-2 had no relationship with each other, while bacterial liquid had great application potential in controlling potato late bright.展开更多
[ Objective] The paper was to screen the antagonistic strain against Phytophthora sojae with biocontrol potential, and provide basis for searching control measures and designing new control strategies against P. sojae...[ Objective] The paper was to screen the antagonistic strain against Phytophthora sojae with biocontrol potential, and provide basis for searching control measures and designing new control strategies against P. sojae. [ Method] The rhizosphere soil of soybean was collected from three different places in Heilongjiang Province, and various soil microorganisms were isolated. Dual culture method was used to screen the microorganism with antagonistic effect against P. sojae. On this basis, the growth inhibition rate of the microorganism with stronger antagonistic effect against P. sojae was determined, and its control effect against P. sojae was also measured. [ Result] A strain of bacterium with relatively good antagonistic effect was isolated from soil, and named as strain B048. Dual test showed that the growth inhibition rate of antagonistic bacterium 11048 against P. sojac reached 97.5%. Antagonistic endurance tests showed that the width of inhibition zone was still 20.0 mm after dual culture with P. sojac for21 d. In potting experiment, the control effect of B048 against P. sojae was 100%. The antagonistic bacterium was primarily identified to be Bacillus pumilus through morphology and 16S rDNA sequence analysis. [Condusion] The antagonistic bacterium B048 had good prospect to be developed as the biocontrol bacterium against P. sojae.展开更多
[Objective] The paper was to improve polyacrylamide gel electrophorus in Phytophthora infeatans SSR Marker.[Method] With the disease sample of P.infeatans collected from Guyuan in Ningxia Province in 2009 as test mate...[Objective] The paper was to improve polyacrylamide gel electrophorus in Phytophthora infeatans SSR Marker.[Method] With the disease sample of P.infeatans collected from Guyuan in Ningxia Province in 2009 as test material,its DNA was extracted and amplified with PCR,and its products were carried out polyacrylamide gel electrophoresis.[Result] 12% polyacrylamide gel electrophoresis was used to detect primers D13,G11 and PI02,and 8% polyacrylamide gel electrophoresis was used to detect primers PI4B,PI63,SSR4,SSR8 and SSR11,then 0.1% silver nitrate was used to stain,and an ideal electrophoresis and staining effect was obtained.[Conclusion] The electrophoresis and staining method suitable for P.infeatans SSR Marker established in the study had the characteristics of high sensitivity,simple operation and clear bands,which was an effective,simple and quick detection method.展开更多
By investigating occurrence of Phytophthora root rot in fields and isolating P.sojae fromdiseased plants and soils, the distribution of P.sojae in China was surveyed. In addition tonortheast region, P.sojae existed in...By investigating occurrence of Phytophthora root rot in fields and isolating P.sojae fromdiseased plants and soils, the distribution of P.sojae in China was surveyed. In addition tonortheast region, P.sojae existed in Huanghe-Huaihe basin and Yangtze basin too. Eighty- threeisolates of P.sojae isolated from different areas were identified on virulence using 13differential soybean cultivars, abundant virulence diversity was found in P.sojae. The greaterdiversity in virulence of P.sojae was in isolates from soil than from plants. And the greatestvirulence diversity of P.sojae was found in Yangtze basin.展开更多
[Objective] The paper was to explore the effect of different culture conditions on sporulation quantity of Phytophthora capsici in Capsicum annuum L.var.dactylus M.in Xunhua.[Method] The effects of light hours,pH,medi...[Objective] The paper was to explore the effect of different culture conditions on sporulation quantity of Phytophthora capsici in Capsicum annuum L.var.dactylus M.in Xunhua.[Method] The effects of light hours,pH,medium and temperature on sporulation quantity during isolation and culture process of P.capsici were studied.[Result] The sporulation quantity of P.capsici under the conditions of 24 h/day light,pH 7.0,potato medium（PSA） and 30 ℃ was the largest,and pH,basal medium and temperature had greater impact on sporulation quantity.[Conclusion]The study laid foundation for the study on natural incidence condition of C.annuum in Xunhua.展开更多
The aim of the study was to establish a set of differential strains and to identify soybean resistant genes to Phytophthora root rot and then to apply those strains for analysis of the resistant genes Rps1a,Rps1c,and ...The aim of the study was to establish a set of differential strains and to identify soybean resistant genes to Phytophthora root rot and then to apply those strains for analysis of the resistant genes Rps1a,Rps1c,and Rps1k that soybean cultivars or lines may carry.Virulence formula of 125 Phytophthora sojae isolates were determined using the hypocotyls inoculation technique,the strains,which includ 6 isolates with different virulence formulas,were applied to identify the resistance of 55 soybean cultivars or lines and resistant genes were analyzed using the gene postulating procedure.Eighteen reaction types occurred in 55 cultivars or lines and results of gene postulation indicated that 2 cultivars or lines probably carried gene Rps1c and no cultivar may carry genes Rps1a or Rps1k.A few of soybean cultivars or lines from Huanghuai Region carry Rps genes Rps1a,Rps1c and Rps1k and tend to infect by P.sojae,so resistant cultivars or lines need to be bred and popularized actively.展开更多
[ Objective] To overcome the resistance of Phytophthora parasitica var. nicotianae against metalaxyl and effectively control its damage, new efficient complex agent of metalaxyl was studied and developed. [ Method] Th...[ Objective] To overcome the resistance of Phytophthora parasitica var. nicotianae against metalaxyl and effectively control its damage, new efficient complex agent of metalaxyl was studied and developed. [ Method] The toxieities of nine fungicides against P. parasitica were measured using growth rate method. On this basis, the fungicides with good effects were selected to compound with metalaxyl, and the optimum complex ratio was confirmed. [Result] The toxicity of metalaxyl was the strongest with EC50 of 2. 130 5μg/ml; followed by carbendazim, mancezeb and dimethomorph with EC50 of 2.357 9, 2.639 8 and 2. 778 8 μg/ml. The effect of cyazofamid was the poorest with EC50 of 6. 278 8 μg/ml. The optimum complex ratios of dimethomorph, carbendazim and mancezeb with metalaxyl were 40： 60, 30：70 and 20： 80, and their co-toxicity coefficients were 138.80,124.25 and 115.00, respectively. [ Conclusion] The complex agents had application and promotion value, which could be used to carry out further field trials.展开更多
载体的构建是建立遗传转化体系的基础。以真核表达载体pcDNA3.1(-)/hygro为基本骨架,构建大豆疫霉菌遗传转化载体,通过限制性内切酶酶切、去磷酸化、连接等基因重组技术,将增强型绿色荧光蛋白(Enhanced Green Fluorescent Protein,EGFP...载体的构建是建立遗传转化体系的基础。以真核表达载体pcDNA3.1(-)/hygro为基本骨架,构建大豆疫霉菌遗传转化载体,通过限制性内切酶酶切、去磷酸化、连接等基因重组技术,将增强型绿色荧光蛋白(Enhanced Green Fluorescent Protein,EGFP)基因和来自莴苣霜霉菌(Bremia lactucae)的启动子(ham34)、终止子重组到真核表达载体pcDNA3.1(-)/hygro中,经大肠杆菌转化后对转化子进行了酶切验证,为大豆疫霉菌遗传转化体系的建立提供载体。展开更多
[Objective] This study aimed to investigate the resistance to different fungicides in Phytophthora parasitica var. nicotianae. [Method] Under indoor incubation conditions, the resistance to dimethomorph, metalaxyl-man...[Objective] This study aimed to investigate the resistance to different fungicides in Phytophthora parasitica var. nicotianae. [Method] Under indoor incubation conditions, the resistance to dimethomorph, metalaxyl-mancozeb, propamocarb and ovraclostrobin.dimethomorph in P. parasitica strain isolated from Zhenyuan County in Qiandongnan State was analyzed with colony growth measurement method. [Result] P. parasitica exhibited different levels of sensitivity to four fungicides. To be specific, P. parasitica exhibited the highest resistance to dimethomorph, and ECho reached 1.19 μg/ml. [Conclusion] In Zhenyuan tobacco-growing area, long-term single use of dimethomorph possesses certain resistance risk in prevention and control of black shank disease.展开更多
基金supported by the BASF Open Innovative Platform(Project OI39).
文摘Phytophthora infestans control is a long-standing problem that has caused ongoing difficulties and brought limited success for over a century.Traditional methods,such as fungicides,have drawbacks including high cost,restrictions on organic farming,potential risks to the environment and human health,and the development of resistant strains.In this study,we employed cutting-edge computer-based techniques,including Quantitative Structure-Activity Relationship(QSAR)modeling and molecular docking simulations,to uncover new fungicidal compounds and gain insights into their specific mechanisms of action against P.infestans.QSAR modeling on the number of compounds tested as P.infestans inhibitors was performed using an interactive OCHEM web platform.The predictive ability of the developed classification models had a balanced accuracy(BA)of 77–85%for the training set and BA?89–93%for the validation external test set.During the in vitro testing against P.infestans,thirteen synthesized 2-oxoimidazolidine-4-sulfonamides demonstrated inhibition rates,ranging from 23.6%to 87.4%.The fungicidal potential of six of these fungicides ranged from 79.3%to 87.4%,which is comparable to the activity of known fungicides.Acute toxicity results using the well-known aquatic marker Daphnia magna showed that the most active sulfonamides 3d,3f,3h,3j,3k,and 3l,with LC_(50) values ranging from 13.7 to 52.9 mg/L,are low-toxicity compounds.The molecular docking results demonstrated a potential mechanism of the antifungal action of the studied 2-oxoimidazolidin-4-sulfonamide derivatives via the inhibition of fungal CYP51,a sterol biosynthesis enzyme.
基金supported by the National Natural Science Foundation of China(Grant No.32160712)Science Foundation for Young Scholars of Jiangxi Province(Grant No.20212BAB215029)+4 种基金Key Research and Development Program of Jiangxi Province of China(Grant No.20223BBF61003)Academic and Technical Leader Projects of Major Disciplines in Jiangxi Province(Grant No.20225BCJ23010)Project on Fundamental Research and Talent Cultivation at Jiangxi Academy of Agricultural Sciences(Grant No.JXSNKYJCRC202341)China Agriculture Research System(Grant No.CARS-24-G-08)Jiangxi Province Crop Improved Varieties Joint Project-Excellent germplasm creation of capsicum and breeding of new varieties with high quality and yield
文摘Phytophthora capsici Leonian is a destructive pathogen that affects pepper production worldwide.Resistance breeding has been proposed as the most efficient and eco-friendly management strategy for controlling this pathogen.This study aimed to characterize the genetic architecture of P.capsici resistance in pepper to support its resistance breeding.In this study,a panel of 220 accessions of Capsicum annuum were evaluated for resistance to P.capsici under controlled conditions.The panel was genotyped via genotyping-by-sequencing(GBS),and the resulting 955 772 high-quality variations were used for the population stratification analysis and the identification of chromosome regions associated with resistance against P.capsici.Strong association signals were detected mainly on chromosomes 5(CaRPc5.1) and 10(CaRPc10.1).The associated single nucleotide polymorphisms(SNPs) explained 5.61%-11.71% of the phenotypic variation.The 220 accessions were divided into four genetic clusters,including an ancestral cluster,a transition cluster,and two recently emerged clusters.P.capsici resistance of the four clusters unveiled compromised resistance to P.capsici during modern domestication,which was hypothesized to be a trade-off for desirable horticultural traits.Using bulked segregant analysis(BSA) and whole-genome resequencing(WGR),a major locus in an F_(4:5) population,derived from a cross between the P.capsici-resistant parent A204 and the susceptible parent A198,was mapped to a 1.81 Mb region on chromosome 10,which coincided with the CaRPc10.1 locus.This locus was further fine-mapped into a 32.36 kb region based on two derived F_(5:6) populations consisting of 2 713 individuals.The Capann59Chr10g029350 gene,a likely allelic variation of the Pur4 gene in this interval,was proposed as a strong candidate gene for Phytophthora capsisi resistance.Our results provide molecular perspectives into the P.capsici-resistance mechanism and molecular markers for the improvement of P.capsici resistance in pepper and pave the way for cloning the resistance gene underlying CaRPc10.1.
文摘A complete cDNA of potato Phytophthora infestans-induced hypersensitive response-related protein gene (POTHR-1) was cloned using rapid amplification of cDNA ends (RACE) strategy according to a fragment sequence which we had cloned using suppression subtractive hybridization (SSH) technique. The potato POTHR-1 gene encodes a protein of 225 amino acids, which shares 81% identity with tobacco hin1 gene-enoded protein (harpin-induced protein). Southern blot revealed that there are two to three copies of POTHR-1 in potato genome. The POTHR-1 gene expression in potato leaves showed that its transcripts accumulated remarkably in leaves after 36 h inoculation with P. infestans. Mechanical wounding and jasmonic acid (JA) could induce the POTHR-1 gene expression and osmotic stress just induce a slight accumulation of POTHR-1 gene mRNA, while salicylic acid (SA) had no detectable function on the induction accumulation of POTHR-1 gene transcripts. The potato POTHR-1 gene may preferentially associate with hypersensitive response (HR) or biotic cell death during interaction between host and pathogen.
基金Supported by Natural Science Foundation of Heibei Province(C2011201003)~~
文摘[ Objective ] The paper was to screen bacterial strain with significant antagonistic effect against Phytophthora infestans, so as to provide basis for further development and utilization of antagonistic bacteria to inhibit P. infestans and control potato late bright. [ Method] Plate dual culture and filter paper method were used to determine the inhibition effect of strains in vivo, fermentation broth and bacterial liquid of 61 strains against P. infestans and the resistance-induction effect of SR13-2 strain. [ Result] The inhibition rate of 24 strains among 61 tested strains against mycelial growth of P. infestans was greater than 60%, and the inhibi- tion effect of HT-6 strain was the strongest with the inhibition rate of 89.92%. However, fermentation broth of all tested strains had no significant inhibition effect against P. infestans, while the inhibition effect of bacterial liquid of most strains was significantly higher than strain in vivo; the inhibition effect of $34-1 strain was the strongest with inhibition rate of 91.50%. The bacterial liquid of SR13-2 strain was found to have significant resistance-induction effect with protective rate of 60%. [ Conclusion] The inhibition effect of strains in vivo and fermentation broth of antagonistic strains S34-1 and SR13-2 had no relationship with each other, while bacterial liquid had great application potential in controlling potato late bright.
基金Supported by National Natural Science Foundation of China(30800040)Excellent Youth Science and Technology Fund of Anhui Province(10040606Y04)教育部留学回国人员科研启动基金资助项目~~
文摘[ Objective] The paper was to screen the antagonistic strain against Phytophthora sojae with biocontrol potential, and provide basis for searching control measures and designing new control strategies against P. sojae. [ Method] The rhizosphere soil of soybean was collected from three different places in Heilongjiang Province, and various soil microorganisms were isolated. Dual culture method was used to screen the microorganism with antagonistic effect against P. sojae. On this basis, the growth inhibition rate of the microorganism with stronger antagonistic effect against P. sojae was determined, and its control effect against P. sojae was also measured. [ Result] A strain of bacterium with relatively good antagonistic effect was isolated from soil, and named as strain B048. Dual test showed that the growth inhibition rate of antagonistic bacterium 11048 against P. sojac reached 97.5%. Antagonistic endurance tests showed that the width of inhibition zone was still 20.0 mm after dual culture with P. sojac for21 d. In potting experiment, the control effect of B048 against P. sojae was 100%. The antagonistic bacterium was primarily identified to be Bacillus pumilus through morphology and 16S rDNA sequence analysis. [Condusion] The antagonistic bacterium B048 had good prospect to be developed as the biocontrol bacterium against P. sojae.
基金Supported by Special Research Project of National Nonprofit Industry(3-20)Funded Projects of Modern Agricultural Technology System(nycytx-15)~~
文摘[Objective] The paper was to improve polyacrylamide gel electrophorus in Phytophthora infeatans SSR Marker.[Method] With the disease sample of P.infeatans collected from Guyuan in Ningxia Province in 2009 as test material,its DNA was extracted and amplified with PCR,and its products were carried out polyacrylamide gel electrophoresis.[Result] 12% polyacrylamide gel electrophoresis was used to detect primers D13,G11 and PI02,and 8% polyacrylamide gel electrophoresis was used to detect primers PI4B,PI63,SSR4,SSR8 and SSR11,then 0.1% silver nitrate was used to stain,and an ideal electrophoresis and staining effect was obtained.[Conclusion] The electrophoresis and staining method suitable for P.infeatans SSR Marker established in the study had the characteristics of high sensitivity,simple operation and clear bands,which was an effective,simple and quick detection method.
基金supported by the National Natural Science Foundation of China(39970497)Nationa1 Basic Work Program of China(2001BA509B0608).
文摘By investigating occurrence of Phytophthora root rot in fields and isolating P.sojae fromdiseased plants and soils, the distribution of P.sojae in China was surveyed. In addition tonortheast region, P.sojae existed in Huanghe-Huaihe basin and Yangtze basin too. Eighty- threeisolates of P.sojae isolated from different areas were identified on virulence using 13differential soybean cultivars, abundant virulence diversity was found in P.sojae. The greaterdiversity in virulence of P.sojae was in isolates from soil than from plants. And the greatestvirulence diversity of P.sojae was found in Yangtze basin.
文摘[Objective] The paper was to explore the effect of different culture conditions on sporulation quantity of Phytophthora capsici in Capsicum annuum L.var.dactylus M.in Xunhua.[Method] The effects of light hours,pH,medium and temperature on sporulation quantity during isolation and culture process of P.capsici were studied.[Result] The sporulation quantity of P.capsici under the conditions of 24 h/day light,pH 7.0,potato medium（PSA） and 30 ℃ was the largest,and pH,basal medium and temperature had greater impact on sporulation quantity.[Conclusion]The study laid foundation for the study on natural incidence condition of C.annuum in Xunhua.
基金funded by the Soybean Industrial Science and Technology System of China (Nycytx-004)
文摘The aim of the study was to establish a set of differential strains and to identify soybean resistant genes to Phytophthora root rot and then to apply those strains for analysis of the resistant genes Rps1a,Rps1c,and Rps1k that soybean cultivars or lines may carry.Virulence formula of 125 Phytophthora sojae isolates were determined using the hypocotyls inoculation technique,the strains,which includ 6 isolates with different virulence formulas,were applied to identify the resistance of 55 soybean cultivars or lines and resistant genes were analyzed using the gene postulating procedure.Eighteen reaction types occurred in 55 cultivars or lines and results of gene postulation indicated that 2 cultivars or lines probably carried gene Rps1c and no cultivar may carry genes Rps1a or Rps1k.A few of soybean cultivars or lines from Huanghuai Region carry Rps genes Rps1a,Rps1c and Rps1k and tend to infect by P.sojae,so resistant cultivars or lines need to be bred and popularized actively.
基金Supported by Key Project of Sichuan Education Department "Study on Physiological Race of Tobacco Black Shank in Liangshan and Resistance Evaluation of Tobacco Germplasm Resources in Sichuan Province"(08ZA032)~~
文摘[ Objective] To overcome the resistance of Phytophthora parasitica var. nicotianae against metalaxyl and effectively control its damage, new efficient complex agent of metalaxyl was studied and developed. [ Method] The toxieities of nine fungicides against P. parasitica were measured using growth rate method. On this basis, the fungicides with good effects were selected to compound with metalaxyl, and the optimum complex ratio was confirmed. [Result] The toxicity of metalaxyl was the strongest with EC50 of 2. 130 5μg/ml; followed by carbendazim, mancezeb and dimethomorph with EC50 of 2.357 9, 2.639 8 and 2. 778 8 μg/ml. The effect of cyazofamid was the poorest with EC50 of 6. 278 8 μg/ml. The optimum complex ratios of dimethomorph, carbendazim and mancezeb with metalaxyl were 40： 60, 30：70 and 20： 80, and their co-toxicity coefficients were 138.80,124.25 and 115.00, respectively. [ Conclusion] The complex agents had application and promotion value, which could be used to carry out further field trials.
文摘载体的构建是建立遗传转化体系的基础。以真核表达载体pcDNA3.1(-)/hygro为基本骨架,构建大豆疫霉菌遗传转化载体,通过限制性内切酶酶切、去磷酸化、连接等基因重组技术,将增强型绿色荧光蛋白(Enhanced Green Fluorescent Protein,EGFP)基因和来自莴苣霜霉菌(Bremia lactucae)的启动子(ham34)、终止子重组到真核表达载体pcDNA3.1(-)/hygro中,经大肠杆菌转化后对转化子进行了酶切验证,为大豆疫霉菌遗传转化体系的建立提供载体。
文摘[Objective] This study aimed to investigate the resistance to different fungicides in Phytophthora parasitica var. nicotianae. [Method] Under indoor incubation conditions, the resistance to dimethomorph, metalaxyl-mancozeb, propamocarb and ovraclostrobin.dimethomorph in P. parasitica strain isolated from Zhenyuan County in Qiandongnan State was analyzed with colony growth measurement method. [Result] P. parasitica exhibited different levels of sensitivity to four fungicides. To be specific, P. parasitica exhibited the highest resistance to dimethomorph, and ECho reached 1.19 μg/ml. [Conclusion] In Zhenyuan tobacco-growing area, long-term single use of dimethomorph possesses certain resistance risk in prevention and control of black shank disease.
