Effect of fungicide thiram on microbial communities of rice seed surface estimated by culture-dependent and culture-independent (PCR-RFLP) methods

Coating of rice seeds with fungicide Thiram improved the seed germination capability over a long period of time (11 weeks) under low temperature conditions (4 and 8°C), which simulated the sowing of rice seeds in the winter season (the farmer's slack season). To analyze the effect of Thiram on the community structure of microorganisms on the rice seed surface, culture-dependent and culture-independent (PCR-RFLP) methods were applied. PCR-RFLP patterns of 16S rDNA showed that the bacterial communities on the rice seed surface were different between coated and uncoated treatments under 8°C conditions, but that they were very similar under 4°C conditions. PCR-RFLP patterns of 18S rDNA revealed the remarkable effect of Thiram on the fungal community structure under both 4 and 8°C conditions. Although the fungal communities were quite different between coated and uncoated seeds at the beginning of incubation, the fungal communities on the coated seed surface became similar to those of uncoated seeds along with the duration of the incubation period. As the dominance percentage of Fusarium spp. among the isolates increased with the duration of the incubation period for both coated and uncoated seeds, Fusarium was considered to be a responsible for the poor germination of rice seeds that were sown in the winter season.     

多菌灵15%+福美双15%可湿性粉剂对九重葛插穗生长的影响

用多菌灵15%+福美双15%可湿性粉剂配制1.00～10.00 g/L 10个不同浓度系列,对九重葛插穗进行3 h浸泡处理后扦插试验.结果表明,各处理中最佳的插穗平均生根数、根长、根直径、叶片数、新枝数、新枝长分别为34.2片、25.28 mm、1.16 mm、39条、3.8条、141.6 mm,最高成活率达到100%,所测生长指标与对照组的差异极显著(P＜0.01).处理剂量在1.00～2.50 g/L,插穗生根数、成活率、根长、根径、新叶数、新枝数和新枝长均与处理剂量的关系呈二次曲线模型(R2＞0.94).结果分析显示,最佳处理的理论剂量为1.82 g/L.     

抗福美双假单胞菌株的NTG化学诱变及分子探针鉴定

利用微生物的抗药性筛选抗福美双的假单胞菌株Ｔ４６，然后通过亚硝基胍（ＮＴＧ）化学诱变获得了对福美双敏感的三株突变株Ｔ４６Ｎ１０、Ｔ４６Ｎ７和Ｔ４６Ｎ１７。利用这三个突变株作受体，通过基因克隆的方法筛选到了可使三个突变株恢复抗性的克隆，抗性基因分别被定位在７ｋｂ、２．５ｋｂ和２０ｋｂ的ＥｃｏＲⅠ片段上。将这三个克隆分别用（３２）Ｐ标记后制成分子探针，然后分别与三个突变菌株的总ＤＮＡ进行ＤＮＡ－ＤＮＡ分子杂交，结果表明，各突变株均存在与菌株Ｔ４６的抗福美双基因克隆的高度同源性，经结合形态、生理生化等分析后证实这三株突变株均源自于出发菌株Ｔ４６。     

克·福·唑酮悬浮种衣剂的液相色谱分析研究

采用液相色谱法 ,对克·福·唑酮悬浮种衣剂进行定量分析。选用苯基柱 ,以甲醇和水为流动相 ,种衣剂中各成分得到较好的分离。方法的标准偏差分析为 0 11、0 0 4和 0 0 5 ,变异系数分别为 0 74、0 37和 0 4 8,回收率分别为 99 6 %～ 10 1 0 %、98 4 %～ 10 0 6 %和 99 7%～ 10 0 3%。     

高效液相色谱法测定食用菌中福美双残留量

建立食用菌中福美双残留量的高效液相色谱(HPLC)检测方法.新鲜食用菌子实体样品粉碎后经二氯甲烷超声(53 Hz)提取20 min,离心(3320 g、5 min),二氯甲烷经氮气吹干,甲醇定容后用HPLC测定.以等体积甲醇和0.1％甲酸水溶液为流动相,1 mL/min等度洗脱,在0.05～10 μg/mL范围内,福美双的峰面积与其浓度呈线性相关,R≥0.999,方法检出限为0.02 mg/kg,添加回收率为79.4％～90.2％,变异系数为1.15％～7.51％％.     

Influence, optimization, energy budgeting and monetary considerations of different time intervals between fungicidal seed treatment and sowing on Sclerotium blight of soybean

Soybean (Glycine max (L.) Merrill) is susceptible to the fungal pathogen, Sclerotium rolfsii from seedling emergence to pod fill. A few systemic and non-systemic fungicides have been recommended as pre-sowing seed treatment (ST) for the management of Sclerotium blight of soybean worldwide. But farmers, especially in developing countries do not utilize ST mainly on account of preoccupation in other practices considered by them essential for sowing. The possibility of ST applied well in advance of sowing was therefore investigated. Results indicated that ST on average increased field emergence by 26.19%, reduced post-emergence mortality (POM) by 49.03% and enhanced seed yield by 23.00%. Seed treatment with carboxin 37.5% + thiram 37.5% @ 0.2% was the best. Seed treatment 50 days prior to sowing was superior by increasing emergence, reducing POM and enhancing seed yield with high monetary returns and energy output.     

27;吡·福·多悬浮种衣剂的研制

介绍了27;吡·福·多悬浮种衣剂有效成分配比的室内筛选、助剂配方研究、主要技术指标和田间药效等.田间试验表明:27;吡*福*多悬浮种衣剂在试验剂量下对棉花出苗无不良影响,以1∶40～60的药种比例处理棉花种子,对棉花苗期病虫害(地老虎、棉蓟马、立枯病)具有较好的防效.     

火把对柑桔炭疽病菌的室内毒力试验

采用菌丝生长速率法,用杀菌剂火把对柑桔炭疽病菌进行了室内毒力测定,测得火把对柑桔炭疽病的EC50值为0.8110μg/mL,EC98值为10.5435μg/mL,确定了其在室内有效抑菌浓度。本试验有利于指导进一步的室外药效试验以确定实际应用中的最佳施用浓度。     

The fungicides thiram and captan affect the phenotypic characteristics of Rhizobium leguminosarum strain C1 as determined by FAME and Biolog analyses

 We assessed the effects of the fungicides captan and thiram on the survival and phenotypic characteristics of Rhizobium leguminosarum bv. viceae, strain C1. Fungicide was applied to pea seed at rates of 0.25–2 g a.i. kg^–1 seed, and treated seed was inoculated with strain C1. After 24 h, rhizobia were extracted from treated seed and viable numbers determined by plating onto yeast extract mannitol agar. Phenotypic characteristics were assessed using FAME (fatty acid methyl ester) profiles and Biolog substrate utilization patterns. Captan and thiram significantly reduced the numbers of rhizobia recovered from seed and altered the FAME and Biolog profiles of recovered rhizobia. However, only the highest concentrations of captan affected nodulation and plant growth. Contact with some seed-applied fungicides can significantly alter phenotypic characteristics of rhizobia, but these changes might be offset by the presence of host plants. Received: 20 February 1999     

小麦种子尿素育肥技术与应用效果研究

用2%浓度尿素溶液处理小麦种子对出苗有良好的促进作用,尿素与福美双混用处理小麦种子比单用福美双出苗率增加5.6%,根长提高32%,根鲜重提高45%,氨基酸含量平均提高11.9mg/100克鲜重;叶绿素平均提高0.537%,降低根腐病发病率14%;增产18.6%大面积生产应用具有显著的社会效益和经济效益。