共查询到19条相似文献，搜索用时 250 毫秒
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土槿皮乙酸（pseudolaric acid B, PAB）是一个结构独特的天然二萜酸,前期发现该化合物对芒果胶孢炭疽菌等多种植物病原真菌具有广谱的抑菌活性,但其杀菌作用机制未知。本研究以芒果胶孢炭疽菌菌株JB-Q为供试对象,采用药剂驯化、紫外照射和钴辐射等方法诱导产生抗PAB的突变体,并分析抗性菌株的生物适合度。结果表明,仅药剂驯化法得到了18株不同抗性水平且可稳定遗传的抗PAB的胶孢炭疽菌,抗性频率为1.69×10-7。适合度研究表明,所有供试菌株在15~35℃范围内均能生长,且在25℃时菌丝生长速率达到最大值;而不同抗性水平的突变菌株的生长速率存在一定差异,其中低抗菌株>亲本菌株>中抗菌株>高抗菌株;渗透压测试结果表明,亲本菌株对0.02% 十二烷基硫酸钠（sodium dodecyl sulfate, SDS）表现更为敏感,其抑制率高达70%;在金属离子（NaCl、KCl和CaCl2）胁迫下,抗性突变菌株则表现更为敏感。因此,研究认为PAB不易导致胶孢炭疽菌的抗性产生,但诱导产生的抗性突变菌株的生存竞争力与敏感菌株相当。此外,交互抗性结果显示,土槿皮乙酸与吡唑醚菌酯、咪鲜胺和戊唑醇之间不存在交互抗性,但与苯并咪唑类杀菌剂多菌灵存在正交互抗性,其皮尔逊相关系数为0.7729（P<0.01）,这表明PAB可能与微管抑制剂多菌灵有相似的作用机制,但仍需开展进一步的研究验证。 相似文献
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转Pi-d2基因水稻对稻瘟病的抗性分析 总被引：4，自引：0，他引：4
对由pCB6.3kb、pCB5.3kb和pZH01-2.72kb三个不同表达载体转化的转稻瘟病抗性基因Pi-d2水稻株系进行稻瘟病抗性分析。结果表明,转Pi-d2基因水稻的9个高代株系对来自四川的39个稻瘟病菌株表现不同的抗性,抗病频率最高达91.7%;4个转基因早代纯合株系对来自中国农业科学院的58个菌株中的81.48%以上菌株表现抗性,具有广谱抗性特点。稻瘟病菌粗毒素筛选结果表明,来自转基因植株的幼胚愈伤组织诱导率随培养基中粗毒素浓度提高而降低,粗毒素浓度达到40%时,幼胚愈伤诱导率为49.33%,受体对照幼胚愈伤组织诱导率为5%。田间诱发条件下,转基因株系在大田的穗瘟发病率为0%～50%,抗性较受体对照大幅度提高。 相似文献
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2008~2011年在黑龙江省共分离了41个马铃薯晚疫病菌,并测定了这些菌株对瑞毒霉和霜脲氰的敏感性和交互抗性。瑞毒霉测定结果显示6个(14.63%)菌株显示为敏感性,11个(26.83%)菌株显示为中抗,24个(58.54%)菌株显示为抗性。这说明黑龙江省分离的晚疫病菌已对瑞毒霉产生抗性。对于霜脲氰,EC50值为0.0630~2.1289μg/mL,最不敏感菌株是最敏感菌株的33.79倍,敏感性基线值为0.1879μg/mL。交互抗性分析结果显示,未产生交互抗性的菌株为73.16%,产生交互抗性菌株为26.84%。以上结果说明霜脲氰和瑞毒霉不能交叉使用。 相似文献
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棉花研究与发展公司资助 CSIRO研究棉铃虫是否对 Bt产生抗性 ,研究者了解到在世界许多地方的小菜蛾已对喷洒的 Bt农药产生了很强的抗性。随后的研究表明 ,多于 2 6种害虫对 Bt蛋白产生了稳定的抗性。建立了来自田间和实验室棉铃虫群体的一个实验室群体 ,新孵化的幼虫取食Cry1 Ac蛋白晶体和 Bt孢子 ,选择 1 6代后 ,大多数快速生长的棉铃虫对晶体和孢子混合物已产生了抗性。 2 1代对 Cry1 Ac的抗性是 1～ 1 2代的 5 0多倍 ,是实验室敏感群体的 30 0多倍。当把一龄幼虫放到长大的抗虫棉棉株上 ,它们可以取食并完成幼虫的发育 ,而来自敏感… 相似文献
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为给河南省抗茎基腐病品种合理布局提供品种支撑,以河南省小麦茎基腐病的高致病力假禾谷镰孢菌菌株PY20-20为接种物,对参加河南省主要区域试验的308个小麦新品系进行苗期抗病鉴定。结果发现,供试品系中,95.7%的品系表现为高感(病情指数大于30.00),仅1.95%的品系表现为中抗(病情指数在10.01～20.00之间),3.25%的品系表现为中感(病情指数在20.01～30.00之间),无免疫和高抗品种,表明参加河南省小麦区域试验的新品系对小麦茎基腐病的整体抗性水平较低。为获得茎基腐病抗性稳定的品系,对苗期表现为中抗和中感的品系进行了2次重复验证,发现6个中抗品系(西农1125、郑麦9134、中研麦906、阜麦1008、泰禾麦6号和民研186)和4个中感品系(徐麦14017、周麦36、新麦9389和囤麦257)的抗性水平较为稳定。进一步对6个中抗品系进行成株期抗性鉴定,发现这些品系的病情指数在12.67～15.50之间,成株期对小麦茎基腐病的抗性也达到了中抗水平。综上,西农1125、郑麦9134、中研麦906、阜麦1008、泰禾麦6号和民研186这6个中抗茎基腐病的品系可以在小麦生产... 相似文献
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采用喷雾接种法和田间自然诱发法,测定福建省11个鲜食玉米品种在苗期和成株期对玉米小斑病的抗性,并探讨抗感病玉米品种间作对病害发生的影响。结果表明,不同玉米品种在苗期对301株小斑病菌群体均表现出不同程度的抗、感病性,品种之间对菌株群体的抗性频率为32.23%～72.76%,其中榕甜1号和永珍7号的抗性频率较高;供试玉米品种在成株期对小斑病的病情指数存在显著差异,其中榕甜1号、永珍7号和闽甜4号均表现为中抗。田间抗感病玉米品种间作试验发现,在福州试验田感病品种粤甜22分别与抗病品种榕甜1号、永珍7号间作后的病情抑制率为33.78%和25.41%;在屏南试验田相同的间作处理两年病情抑制率分别达58.35%、21.05%和52.56%、46.42%。 相似文献
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采用菌丝生长速率法,对采自广西6个冬瓜和黄瓜产区的116株瓜类疫霉菌进行烯酰吗啉的敏感性检测。结果表明:敏感菌株和中间型菌株分别占测试菌株的8.6%和91.4%,以中间型菌株为优势菌群,所有样区均未检测到抗性菌株;待测菌株的EC50值范围为0.081 3~1.340 0μg/m L,最不敏感菌株是最敏感菌株的16倍,平均EC50值为(0.274 6±0.092 8)μg/m L;116株瓜类疫霉对烯酰吗啉的敏感性分布呈单峰曲线,未出现敏感性下降的亚群体,可将其单峰曲线作为瓜类疫霉对烯酰吗啉的敏感性基线,将烯酰吗啉对该病原群体的平均EC50值作为田间抗药性检测的参考标准。通过室内对敏感菌株进行药剂驯化选育20代,获得抗性指数大于2.0的抗药突变体3株;采用紫外线处理未获得有明显抗性的突变体。3株突变体的部分生物学性状结果表明,突变体对寄主的致病力明显弱于其亲本菌株,突变株DRGL-4和DRYL-154菌株几乎丧失致病力;在不同p H及不同温度培养条件下,部分抗药突变体菌丝生长率与亲本菌株相比均有不同程度的提高。综合分析表明,在当前的管理水平和栽培模式下,瓜类疫霉菌抗药突变体群体在田间难以形成和发展,烯酰吗啉属于低抗性风险的用于防治瓜类疫病的有效杀菌剂。 相似文献
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甘蓝型油菜菌核病抗(耐)性的遗传研究Ⅰ. 抗性遗传属性与配合力分析 总被引：12，自引：3，他引：9
以来自欧洲和中国的 6个抗 (耐 )、感病品种 (系 )为材料 ,用双列杂交和火柴棒接种法研究油菜菌核病抗性的遗传属性与配合力。结果表明 ,油菜菌核病抗性主要受核基因控制 ,但存在一定的母性效应 ,核基因作用方式表现为显性和加性基因作用。油菜菌核病抗性表现为部分显性 ,不同抗 (耐 )病品种的抗性显性程度存在差异。抗病品系 0 2 0的抗性相对显性率较高 ( 2 2 .0 8% ) ,Norin9的抗性相对显性率较低 ( 6.0 1 % )。亲本0 1 8的一般配合力效应值较高 ( 4.4 6) ,Cobra较低 ( -1 0 .54) ,Cobra× 0 1 8组合的特殊配合力较高并具有良好经济性状 ,为试验最优组合。 相似文献
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Jadwiga Śliwka Sylwester Sobkowiak Renata Lebecka Jose Avendaño-Córcoles Ewa Zimnoch-Guzowska 《Potato Research》2006,49(3):155-166
A total of 93 single-lesion isolates of Phytophthora infestans were collected from late blight diseased potatoes grown in several locations in Poland, in the years 2002–2004. They were
tested for mating type, virulence, aggressiveness and metalaxyl resistance. Sixty one percent of the isolates was of the A1
and 39% of the A2 mating type. Regarding virulence, complex races predominated. Most of the isolates were highly and moderately
aggressive. Among isolates, tested together with 38 previously collected (1995–2001) ones, 14.5% was metalaxyl resistant,
3.5% intermediately resistant and 82.0% of the isolates was sensitive to metalaxyl. In addition, 14 isolates tested with three
simple sequence repeat markers showed high genetic diversity. These data indicate that Polish population of P. infestans is diverse and aggressive, with potential for sexual recombination and spreading of fungicide insensitivity. 相似文献
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K. L. Deahl S. P. DeMuth S. L. Sinden A. Rivera-Peña 《American Journal of Potato Research》1995,72(1):35-49
The A2 mating type ofPhytophthora infestans was first reported in the United States in 1990. Concurrently,P. infestans strains resistant to metalaxyl ere found in the Pacific Northwest. Collaborative surveys were undertaken during 1991–1993 to investigate the frequency of occurrence of A2 mating types and metalaxyl resistant strains in populations ofP. infestans isolated from outbreaks of late blight in potato and tomato crops in North America.In vitro testing indicated that isolates from the northeastern U.S. and Atlantic Canada were primarily (52/55) metalaxyl sensitive and all were A1 mating types. Among 85 isolates from late blight epidemics in Florida and Texas, greater than 61% were both metalaxyl resistant and A2 mating type. Metalaxyl resistance and A2 mating types were identified also in a few tomato isolates from North Carolina. Although the majority of 134 isolates from the Pacific Northwest (British Columbia and Washington) were metalaxyl resistant, only 2 isolates from Washington were A2 mating types. Among 111 isolates from 2 sites in central Mexico, 63% and 77% were both metalaxyl resistant and A2 mating types. The data indicate also a higher frequency of metalaxyl resistance in A2 isolates, than in A1 isolates, among isolates from Florida and Texas. Highest metalaxyl resistance levels were found, however, in A1 isolates from California, where no A2 isolates were recovered. 相似文献
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Outbreaks of late blight occurred in commercial potato fields in northwestern Washington in 1989 and reached epidemic proportions in 1990. Since most blighted fields reportedly had received 2–4 late-season applications of metalaxyl, the possibility existed that pathogenic strains ofPhytophthora infestans had developed resistance to this systemic fungicide. In testing this hypothesis,P. infestans was isolated consistently from diseased leaves, stems, and tubers of potato when small tissue pieces were surface-disinfected in 0.5% NaOCl for 3 min. Virulence of isolates was assessed on detached leaflets of eight differential (R-gene) potato genotypes. Although simple races (single and double) were recovered, there was also a high frequency of complex race combinations. When tested in metalaxyl-amended media, 81% of the 73 isolates recovered from diseased tissues were highly resistant to 10 μg metalaxyl/ml and 19% yielded intermediate resistance. Sensitive isolates were not recovered. Fifty-five percent of 40 isolates sporulated on potato tuber disks in the presence of ≥10 ug metalaxyl/ml. On leaf tissues, 85% of 20 isolates sporulated in the presence of 10 μg metalaxyl/ml, and 50% sporulated in the presence of 100 μg/ml. This is the first report ofP. infestans resistance to metalaxyl in the U.S. 相似文献
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2006～2008年在黑龙江省和吉林省共分离获得99株马铃薯晚疫病菌,并测定了这些菌株的交配型、瑞毒霉敏感性、同工酶基因型和mtDNA单倍型。交配型测定结果显示在吉林省和黑龙江省分离的所有菌株均为A1交配型。瑞毒霉敏感性测定结果显示敏感性菌株占14.1%,中抗菌株占7.1%,抗性菌株占78.8%,表明吉林省和黑龙江省发生的晚疫病菌已对瑞毒霉产生抗药性。黑龙江省和吉林省分离的所有菌株中发现了两种mt DNA单倍型(Ⅰa和Ⅱa)。其中,Ⅰa单倍型占11.1%,Ⅱa单倍型占88.9%。根据Gpi和Pep图谱,本试验发现了3种同工酶基因型,其中优势同工酶基因型是Gpi:100/100,Pep:100/100。根据菌株的交配型、同工酶基因型和mtDNA单倍型,共发现4种基因型,其中,multi-locus基因型A(84.9%)是黑龙江省和吉林省发现的优势基因型,但也出现了新的基因型分化。 相似文献
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Xiaodan Wang Mei Guo Fanxiang Min Yunfei Gao Feifei Xu Shuai Yang Dianqiu Lu 《Potato Research》2012,55(3-4):217-224
Samples of Phytophthora infestans were isolated from 12 city and county fields in the main potato production areas of Heilongjiang province of China between 2004 and 2008. A total of 72 isolates were tested for virulence on a potato R gene differential set and 39 of these isolates were also analysed for their resistance to the fungicide metalaxyl. All 11 differential plants were infected by one or more of the isolates collected; the most commonly overcome differentials were R1, R3, R4, R7, R10, and R11. Most (89.7%) of the tested isolates were resistant to metalaxyl and the rest (10.3%) were sensitive. The proportion of metalaxyl-resistant isolates differed between sites (χ 2?=?25.42, df?=?10, p?<?0.005), but not between years (χ 2?=?4.63, df?=?4, p?>?0.05). Taken together and in comparison with earlier pathogen population studies, our findings suggest that the population of P. infestans in Heilongjiang is different from that existing in the province two decades ago and that at various locations within the province, the new population has a high frequency of resistance to metalaxyl. 相似文献
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Summary Samples of potato foliage infected withPhytophthora infestans were collected from the main potato growing areas in Ireland over a three-year period starting in 1981 when metalaxyl-based
fungicides were no longer commercially available. Using the floating disc method, 75% of the isolates tested were found to
be resistant to metalaxyl in 1981, 21% in 1982 and only 6% in 1983. The reliability of the test method and the sampling procedure
to detect low levels of resistance is discussed. 相似文献
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The distribution of A1 and A2 mating types, and of metalaxyl-sensitive (MS), metalaxyl-intermediate (MI), and metalaxyl-resistant (MR) strains ofPhytophthora infestans, the causal pathogen of late blight, were determined in Canada in 1997. Potato plants or tubers and tomato plants or fruits, suspected to have late blight infection, were received from seven Canadian provinces in 1997, and were assessed for the presence ofP. infestans. Among 220 samples suspected to have late blight,P. infestans was recovered from 132 samples (60%) received from British Columbia (BC), Manitoba, New Brunswick, Prince Edward Island, and Quebec. From the 132 samples, 364 isolates were obtained and tested for their mating type and response to metalaxyl. Populations ofP. infestans within Canadian provinces were homogeneous for mating types, except within BC, where populations comprised both A1 and A2 mating types both within fields and sometimes within samples. The A2 mating type was found in all provinces where late blight was present. The A1 mating type was found only in Manitoba (1 isolate) and in BC (38 isolates). Unlike the old A1 isolates, those found in BC in 1997 were highly resistant to metalaxyl. These A1 isolates are even more resistant than A2 isolates. Based on assays with 10 ug.ml?1 of metalaxyl, 14% of all tested isolates were MS, 69.8% were MI and 16.2% were MR. In addition, all provinces contained MS, MI, and MR isolates. No specific mating type or metalaxyl sensitivity level were specific to tomato or potato. 相似文献
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A total of 134 Czech Pseudoperonospora cubensis isolates originating from Cucumis sativus were used for fungicide resistance screening. Efficacy of six commonly used and registered fungicides was screened in Czech P. cubensis populations. The investigations covered the frequency and occurrence of sensitive, moderately resistant and resistant isolates to the individual fungicides during the period 2005–2010. Fosetyl-Al (Aliette 80 W) and propamocarb (Previcur 607 SL) were the most effective fungicides. All tested isolates were sensitive on all tested fosetyl-Al concentrations. However, some isolates expressed resistance (profuse sporulation) or moderate resistance (limited sporulation) to lower and/or even to recommended concentrations of propamocarb in the years 2006 and 2008–2010. Metalaxyl (Ridomil PLUS 48 WP) and metalaxyl-M (Ridomil Gold MZ 68 WP) were ineffective. Isolates collected in 2008 and 2009 showed large variation in moderate resistance or resistance even at high fungicide dosages. However, this result was not confirmed in 2010, when efficacy of these fungicides increased slightly, and 69% and 43% of isolates were controlled at the recommended concentration of metalaxyl-M and metalaxyl, respectively. Limited or profuse sporulation was observed only sporadically at high concentrations. Sensitivity of isolates to cymoxanil (Curzate K) differed among the studied years. While cymoxanil was ineffective in the years 2005–2008 and in 2010, 68% of isolates were controlled at the recommended concentration in 2009. During the years 2005 through 2010, a shift towards higher sensitivity to dimethomorph was observed at all screened concentrations. 相似文献
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陕西省小麦白粉菌对三唑酮的抗药性监测 总被引：2，自引：0，他引：2
为给三唑酮在小麦白粉菌防治中的合理应用提供依据,采用拌种离体叶段法测定了陕西省4个市19个乡镇的166个小麦白粉菌菌株对三唑酮的抗药性。结果表明,供试菌株对三唑酮的平均EC50为34.66mg.L-1,平均抗药性水平为16.58倍,80.72%的菌株产生了抗药性。其中,高抗菌株(抗药性水平>40倍)占9.64%,中抗菌株(10倍<抗药性水平≤40倍)占37.35%。咸阳市武功县普集镇、宝鸡市岐山县高店乡和益店镇以及眉县横渠镇小麦白粉菌抗药性高于其他地区。说明陕西省关中大部分地区的小麦白粉菌已对三唑酮产生了抗药性,且抗药性呈增加趋势,但与全国范围相比,抗药性水平相对较低。 相似文献