Sensitivity of populations ofBotrytis cinerea to triazoles,benomyl and vinclozolin

Sensitivity of field isolates (121) ofBotrytis cinerea from France (1992), Germany (1979–1992), Israel (1990) and the Netherlands (1970–1989) to the triazoles tebuconazole and triadimenol, the benzimidazole benomyl and the dicarboximide vinclozolin were tested in radial growth experiments. Resistance to benomyl (in 21 to 100% of isolates tested) and vinclozolin (in 25 to 71% of isolates tested) was common in most countries. EC₅₀s (concentrations of fungicides inhibiting radial mycelial growth ofB. cinerea on B5-agar by 50%) for tebuconazole and triadimenol ranged between 0.01–1.64 and 0.4–32.6g ml^–1, respectively, and were log-normally distributed. The variation factor (ratio between EC₅₀s of the least and most sensitive isolate tested) amounts 164 and 82 for tebuconazole and triadimenol, respectively. These values are comparable to those for azole fungicides applied in control of other pathogens. Hence, variation in sensitivity to triazoles can probably not explain limited field performance of triazoles towardsB. cinerea. Isolates from south west Germany (1992) were significantly less sensitive to tebuconazole than isolates collected earlier in Germany, Israel and the Netherlands. Such less sensitive populations may contribute to the limited field performance of DMI fungicides towardsB. cinerea. The sensitivity of isolates from south west Germany to tebuconazole was similar to that of DMI-resistant mutants generated in the laboratory. These mutants displayed stable resistance with Q-values (ratio between EC₅₀ of resistant mutant and wild type isolate) between 5 and 20. Sensitivity of field isolates and laboratory mutants to tebuconazole and triadimenol was correlated.     

吲哚乙酸引导下三唑醇在大豆植株中的传导与积累研究初报

将吲哚乙酸与三唑醇发生酯化反应后生成的吲哚乙酸三唑醇酯 ,在0.5 mmol/L浓度下水培和喷雾处理6~8叶期大豆植株,同时以相同浓度的三唑醇及其与吲哚乙酸的混合物为对照,色谱法测定不同时间植株不同部位吲哚乙酸三唑醇酯和三唑醇的含量。结果表明,与对照相比,吲哚乙酸三唑醇酯在大豆中具有明显的双向传导和向根部积累的特点。喷雾处理后,在12~60 h之间内吸量和根部积累量均出现最大值。     

戊唑醇和三唑醇种衣剂对小麦幼苗生长发育的影响

三唑醇、戊唑醇用于小麦种子处理,当包衣浓度分别高于０．３ｇ ａｉ／ｋｇ种子和０．６ｇ ａｉ／ｋｇ种子时,对小麦的发芽及出苗都有较为严重的影响;对小麦的生长发育有明显的影响主要表现为株高降低,根长、胚芽鞘高度、第１片真叶长减小,而分根数增加,第１片真叶宽增大;除包衣用量大于１．２ｇ ａｉ／ｋｇ种子百株鲜重明显降低外,其余与空白对照无明显差异。相同用量下,戊唑醇对小麦幼苗生长发育的抑制作用要比三唑醇的     

Factors affecting build-up of fungicide resistance in powdery mildew in spring barley

In replicate-plot field experiments done in the UK, at one site in Avon for 3 years and another in Warwickshire for 2 years, application of ethirimol or triadimenol sprays or seed treatments was followed by decreases in sensitivity of mildew samples to the particular fungicide applied. Application of ethirimol-triadimenol or tridemorph-triadimenol mixtures caused smaller or no decreases in sensitivity. Differences between isolates in responses to ethirimol and to triadimenol treatment were usually negatively correlated. Early-season inoculum differed in fungicide sensitivity between sites. At one site sensitivity shifted markedly from one season to another. No clear interactions between cultivar, mildew pathotype and shifts in fungicide response could be discerned. There were no major differences in resistance build-up between seed or spray treatments.In veldexperimenten met herhalingen uitgevoerd in Engeland, gedurende een periode van 3 jaar in Avon en gedurende een periode van 2 jaar in Warwickshire, werd na behandeling van zomergerst met ethirimol of triadimenol een verminderde gevoeligheid van meeldauw voor deze fungiciden waargenomen.Behandelingen met mengsels van ethirimol-triadimenol of tridemorf-triadimenol gaven weinig tot geen verminderde gevoeligheid. Verminderde gevoeligheid van isolaten voor ethirimol was meestal gecorreleerd met een verhoogde gevoeligheid voor triadimenol en omgekeerd. Vroeg in het seizoen werd in de meeldauwpopulatie op de twee proefvelden een verschil in gevoeligheid voor de fungiciden waargenomen. Op één proefveld trad van het ene op het andere seizoen een aanzienlijke verandering in de gevoeligheid voor de fungiciden op. Er was geen duidelijke correlatie tussen de waargenomen verminderde gevoeligheid voor de fungiciden en de gebruikte cultivars of voorkomende fysio's. Verminderde gevoeligheid voor de fungiciden werd zowel bij zaadbehandeling als bij het bespuiten van planten waargenomen.     

三唑制剂及其铜唑制剂处理材的防腐性能

为开发新型三唑类木材防腐剂,检测己唑醇、氟环唑和三唑醇制剂处理材的防腐性能,并将其分别与铜氨(胺)络合物复配,采用抑菌圈法确定二者的优化配比.检测结果表明,三唑制剂的载药量为0.05～0.08 kg/m3时,处理材质量损失率≤5％;复配的铜/己唑醇、铜/氟环唑、铜/三唑醇三种铜唑制剂,其优化配比范围分别为99～70∶1、124～70∶1、49～32∶1,适宜的载药量为0.8～1.0 kg/m3.     

液相色谱-质谱法检测油菜子、植株和土壤中三唑醇的残留

建立液相色谱-质谱法检测油菜子、植株和土壤中三唑醇残留量的方法。油菜子和植株经乙腈提取,经Carbon/NH2柱净化,实现样品的制备;土壤则经乙腈提取浓缩后直接检测。在岛津VP-ODS色谱柱上,以乙腈+0.1%甲酸水为流动相,梯度洗脱,采用电喷雾正离子(ESI+)sim扫描离子模式,以m/z 296为定量检测离子。结果表明,三唑醇保留时间在11.9 min左右。在0.02~2.00 mg/L的浓度范围内呈良好的线性关系,其相关系数为0.999 7。在油菜子、植株、土壤中添加0.02、0.20、2.0 mg/kg 3个浓度的三唑醇标样,其回收率为71%~110%,相对标准偏差(n=5)均小于10%,最低检出量(S/N=10)为1.7×10-9 g。该方法准确度和精密度均能满足检测要求。     

三唑醇及其对映异构体在3种不同类型土壤中的降解动态

实验室条件下,初步研究了手性农药三唑醇及其非对映异构体三唑醇A(对映异构体1R,2S体和1S,2R体的混合物)与三唑醇B(对映异构体1R,2R体和1S,2S体的混合物)在浙江杭州潮土(有机质含量1.90%,pH 6.85)、金华水稻土(有机质含量1.63%,pH 4.94)和兰溪红土(有机质含量0.38%,pH 4.03)中的降解动态及对映体之间相互转化的情况。结果表明:三唑醇在潮土、水稻土和红土中的降解半衰期分别为56.4、105.0和154.0 d,180 d时降解率分别为91.9%、79.2%和57.7%;三唑醇在潮土中发生两次三唑醇A体向B体转化和1次三唑醇B体向A体的转化,而在水稻土和红土中,三唑醇A体与B体之间相互各转化1次。表明三唑醇对映异构体的降解动态因土壤性质不同而存在差异。研究结果为三唑醇的科学合理使用及其环境风险评估提供参考。     

气相色谱法测定大豆植株中三唑醇残留量研究

以大豆植株为材料,建立了气相色谱法分析植物组织中三唑醇残留量的方法。结果表明,采用甲醇浸提,弗罗里硅土、活性炭小柱净化;外标法定量,检测器为NPD,载气为氮气,程序升温,HP1701小口径毛细管色谱柱,分流比为2。在此色谱条件下,样品在1～50ug／mL范围内,峰面积与浓度呈明显的线型关系（r=0．9999）,回收率范围在83．43％～103．66％之间,变异系数低于4％,具有较好的准确度和精密度。     

2%三唑醇·戊唑醇种衣剂对小麦纹枯病菌麦角甾醇含量的影响

分别用三唑醇原粉、戊唑醇原粉和2%三·戊种衣剂(1.2%三唑醇＋0.8%戊唑醇,质量分数)处理小麦纹枯病菌Rhizoctonia cerealis后,采用皂化处理样品法提取并用高效液相色谱法测定其体内的麦角甾醇含量。结果表明,随着药剂浓度升高,麦角甾醇的含量逐渐降低,说明药剂浓度越高抑制作用越强。当药剂有效成分浓度为5.0 μg/mL时,7 d后对病菌的抑制率分别为60.4％、63.8％、63.8%。药剂处理浓度相同时,菌丝麦角甾醇的含量高低顺序为:三唑醇处理＞三·戊种衣剂处理＞戊唑醇处理。说明药剂处理菌丝后其体内麦角甾醇的合成受到抑制,从而导致其含量显著降低。     

Genetics of responses to morpholine-type fungicides and of avirulences inErysiphe graminis f. sp.hordei

The genetics of the responses of the barley powdery mildew pathogen,Erysiphe graminis f.sp.hordei, to three morpholine-type fungicides were studied. Resistances to a phenylpropylamine fungicide, fenpropidin, and to a morpholine, fenpropimorph, co-segregated in crosses of a sensitive isolate, DH14, with each of two resistant ones, CC151 and CC152. In the cross CC151×DH14, the results were consistent with resistance to both fungicides being controlled by a single gene, at a locus namedFenl. In the other cross, CC152×DH14, the genetics of resistance were more complicated; the data were consistent with the segregation of two complementary, unlinked genes which each conferred resistance to both fungicides. Fenpropidin-resistant progeny of CC151×DH14 were significantly more resistant to fenpropimorph than were fenpropidin-resistant progeny of CCI 52×DH14, although the resistant progeny of the two crosses did not differ significantly in their level of fenpropidin resistance. Fenpropidin-resistant progeny of CC151×DH14 were significantly more resistant to another morpholine, tridemorph, than were fenpropidin-sensitive progeny, but this was not the case for CC152×DH14. Resistance to triadimenol, a C14 demethylation-inhibitor (DMI) fungicide, segregated in both crosses. Triadimenol resistance appeared to be controlled by one gene in each cross and was not associated with morpholine resistance. CC151×DH14 also segregated for eight avirulence genes. Two of these matched theMla6 resistance, while one gene matched a previously unknown resistance in a Pallas near-isogenic line, P17, which also carries a known resistance gene,Mlk. Fenl was not significantly linked to the triadimenol resistance gene,Tdl(a), or to any of the eight avirulence genes.Avr _a6 1, Avr _a12 ,Avr _La ,Avr _p17 andTdl(a) were linked, as wereAvr _a 10 andAvr _k .Abbreviations ED₅₀ median effective dose - Fpd fenpropidin - Fpm fenpropimorph - PCA principal components analysis - Tdm tridemorph