水溶性氟乐灵纳米制剂对向日葵列当的毒力及田间药效

向日葵列当Orobanche cumana是一种检疫性恶性寄生杂草。本研究采用透析法制备了一种水溶性氟乐灵纳米制剂(Tf-OR-CC),评价其对向日葵列当的室内毒力和田间药效。种子发芽毒力测定结果表明:在独脚金内酯类似物GR24的诱导下,用5μg/mL Tf-OR-CC处理向日葵列当种子,7 d后表现出良好的抑制发芽活性,列当种子发芽率为28.5%,与对照相比差异显著。消解动态试验表明,Tf-OR-CC消解半衰期比48%氟乐灵乳油延长6.56 d,说明Tf-OR-CC具有一定的缓释作用。田间药效试验结果表明,滴灌施用有效成分含量为75 g/667 m~2Tf-OR-CC 45 d后,向日葵列当寄生率为32.1%,寄生强度为5.3,Tf-OR-CC制剂对向日葵列当的田间防效为36.3%。该方法可为向日葵滴灌施药技术防治向日葵列当提供科学依据。     

食物和环境中氟乐灵农药残留检测方法研究进展

氟乐灵农药是一种二硝基苯胺类芽前土壤处理除草剂,在食物和环境中残留严重,会对人体产生危害。主要总结了氟乐灵的残留限量,通过综述色谱法、免疫分析方法、电化学法、光度计法、生物检测法等5种氟乐灵检测方法进展情况,并对氟乐灵检测技术的发展进行展望,为氟乐灵残留检测技术的进一步研究提供参考。     

Mutation of alpha-tubulin genes in trifluralin-resistant water foxtail (Alopecurus aequalis)

BACKGROUND: Trifluralin‐resistant biotypes of water foxtail (Alopecurus aequalis) have been identified in wheat fields from northern Kyushu, Japan. Water foxtail is a winter‐annual grassy weed, causing substantial crop losses. This study reports on mutation in α‐tubulin (TUA) genes from water foxtail, the site of action of trifluralin. RESULTS: Two trifluralin‐sensitive (S) Chikugo and Ukiha biotypes and four trifluralin‐resistant (R) Asakura‐1, Asakura‐2, Tamana and Tosu biotypes of water foxtail were used for herbicide resistance analysis. R biotypes showed 5.7–30.7‐fold trifluralin resistance compared with the S biotypes. No differences in the uptake and translocation of ¹⁴C‐trifluralin were observed between Chikugo (S) biotype and Asakura‐1 (R) biotype. Most of the ¹⁴C detected in the plant material was in the root tissue, and no substantial increases were noted in shoot tissues. Comparative TUA sequence analysis revealed two independent single amino acid changes: change of Val into Phe at position 202 in TUA1 and change of Leu into Met at position 125 in TUA3 in Asakura‐1 biotype. In the Tamana (R) biotype, two amino acid changes of Leu to Phe at position 136 and Val to Phe at position 202 were observed in the predicted amino acid sequence of TUA1, compared with Chikugo (S) biotype. CONCLUSION: The results provide preliminary molecular explanation for the resistance of water foxtail to trifluralin, a phenomenon that has arisen as a result of repeated exposure to this class of herbicide. This is the first report of α‐tubulin mutation in water foxtail and for any Alopecurus species reported in the literature. Copyright © 2011 Society of Chemical Industry     

氟乐灵诱导南瓜染色体加倍初步研究

以南瓜为试材,通过不同浓度的氟乐灵和秋水仙素进行倍性诱导处理.结果表明,浓度为180 μmol·L-1的氟乐灵具有较好的加倍效果,可以有效代替秋水仙素.和秋水仙素相比,氟乐灵使用的浓度低,价格低廉,效果好,且毒性小,对人和环境比较安全.并用流式细胞仪对南瓜诱导的幼苗进行了倍性分析鉴定.     

Formalin as an alternative to trifluralin as prophylaxis against fungal infection in mud crab Scylla serrata (Forsskål) larvae

The toxicity of formalin and trifluralin to the larval stages of the mud crab Scylla serrata was compared in a static bioassay. Prophylactic doses of 5, 10, 15, 20 and 25 μg L⁻¹ formalin and 0.05, 0.1, 0.2, 0.4 and 0.8 μg L⁻¹ trifluralin were used. Toxicity was assessed on the basis of survival of larvae after 24, 48, 72 and 96 h exposure to the test chemicals and metamorphosis to the next larval stage. Result shows that larval survival in all stages was significantly reduced at concentrations of 20 and 25 μg L⁻¹ formalin whereas larvae were able to tolerate all trifluralin treatments. However, larvae became more tolerant to high formalin concentrations as the larval stage progressed. Survival was better at 5, 10 and 15 μg L⁻¹ formalin and in all trifluralin treatments than the control in almost all the larval stages. Faster metamorphosis was observed at 5 and 10 μg L⁻¹ formalin and 0.05, 0.1 and 0.2 μg L⁻¹ trifluralin concentrations. Doses of formalin and trifluralin obtained from the toxicity experiments were applied as prophylaxis to newly hatched larvae in white plastic basins. Prophylactic doses of 5 and 10 μg L⁻¹ formalin and 0.05 and 0.1 μg L⁻¹ trifluralin applied every other day were found to be effective in enhancing survival and larval development to megalopa compared with control. However, no megalopae survived to crab instar in all formalin treatments. Although the use of fungicides in rearing systems resulted in higher survival compared with controls, other strategies (i.e. maintenance of good water quality and hygienic practices in the hatchery) should be further investigated as an alternative to the use of chemicals in hatcheries.     

绿原酸和阿魏酸与棉花对枯萎病抗性的关系

分析了枯萎病菌侵染及氟乐灵诱发处理后棉苗叶片和根茎部组织中可溶性酚、黄酮醇、绿原酸和阿魏酸含量的变化．结果表明：抗病品种棉苗组织中酚类物质的含量高于感病品种；氟乐灵诱发处理促进了棉苗组织中酚类物质的积累；枯萎病菌侵染可明显提高棉苗体内的酚含量．抗病品种棉苗及经氟乐灵诱发并产生诱导抗性的棉苗受侵后其组织中酚含量的增加幅度更大．由此认为，棉花体内的酚类物质，特别是绿原酸和阿魏酸与棉花对枯萎病的抗病性以及由氟乐灵诱发的诱导抗性有关     

氟乐灵在养殖水体环境中消解动态的模拟研究

氟乐灵因具有控制池塘青苔、防治虾蟹类疾病等特点而在虾蟹类水产养殖上广泛应用,为研究其在养殖水体环境中的残留和消解动态,在参考其他方法的基础上建立了分析养殖水体中氟乐灵的气相色谱法。该方法的检出限为0.000 105 mg·L-1,测定下限为0.000 42 mg·L-1,按0.025~2.0 mg·L-1添加标样的加标回收率在82.88%~108.19%,可较为准确地分析氟乐灵在养殖水体环境中的动态变化。研究显示,氟乐灵在养殖水体中具有一定的残留效应,消解半衰期在35 d之内,养殖水体中氟乐灵的消解受氟乐灵初始浓度、水温、光照时间、p H值等因素的影响。因子分析可见,氟乐灵的初始浓度、水温和光照时间是影响其消解的主要因素,在初始浓度为0.05~0.5 mg·L-1时,30℃的水温和一定的光照(>12 h·d-1,2500 lx)可促进氟乐灵的消解。为保证水产品的质量安全,防范可能产生的风险隐患,水产养殖中氟乐灵的使用浓度以0.05 mg·L-1为宜,使用后安排1050℃·d的休药期。     

枯萎病菌侵染后棉苗体内超氧物歧化酶和过氧化氢酶活性的变化及与抗病性的关系

分析了枯萎病菌侵染后棉苗叶 片和根茎部组织中超氧物歧化酶（ Ｓ Ｏ Ｄ）和过氧化氢酶 （ Ｃ Ａ Ｔ）活性的变化动态, 结果表明：抗病品种 和感病品种棉苗 中 Ｓ Ｏ Ｄ 和 Ｃ Ａ Ｔ 酶活性无显著 差异;氟乐灵处 理可诱发棉苗对枯萎病的诱导抗性,且氟乐灵处理的棉苗组织中 Ｓ Ｏ Ｄ 和 Ｃ Ａ Ｔ 酶活性无显著变化;枯萎病菌侵染后棉苗叶 片和根茎部组织 中 Ｓ Ｏ Ｄ 和 Ｃ Ａ Ｔ 酶活 性明显提 高,但抗病品 种棉苗组 织中 Ｓ Ｏ Ｄ 和 Ｃ Ａ Ｔ酶活性在前期 增加不显著,后期增 加较慢,而感病品 种棉苗中两种酶活 性在前期就明 显升高,增加 速度快;氟乐灵处理的棉苗,其组织中两种酶活性始终低于未处理棉苗 接种后的水平⒚棉花组织中的 Ｓ Ｏ Ｄ 酶主要是 Ｃｕ, Ｚｎ Ｓ Ｏ Ｄ,受侵后 Ｓ Ｏ Ｄ 酶活性的升高主要来自于 Ｃｕ , Ｚｎ  Ｓ Ｏ Ｄ⒚因此, Ｓ Ｏ Ｄ 和 Ｃ Ａ Ｔ 与棉花对枯萎病的抗性及由氟乐灵诱发的诱导抗性无关⒚     

Microspore culture of white cabbage, Brassica oleracea var. capitata L.: Genetic improvement of non-responsive cultivars and effect of genome doubling agents

For the efficient application of haploid induction procedures in cabbage breeding, a sufficient number of regenerants should be achieved in a broad spectrum of genotypes. However, the majority of genotypes are somewhat recalcitrant. The efficiency of microspore culture was tested by crossing a responsive (28.7 embryos per Petri dish) and a non- responsive (0.1 embryo) cabbage cultivar. The embryo yield of one progeny was intermediate (18.9) while two were superior to the best parent cultivar (52.9 and 64.0 embryos). Thus, genes for haploid embryogenesis, present in responsive lines, can be effectively transmitted to responsive × non-responsive hybrids. Abscisic acid-induced desiccation of embryos was used for the efficient regeneration of plants. High germination percentages (54.7-70.6%) followed by normal plantlet development were achieved. Spontaneous genome doubling measured at the plantlet stage differed markedly in untreated genotypes. The percentage of diploids ranged from 21 to 67%. The effects of two antimitotic drugs applied to freshly isolated microspores were determined in two experiments. In the first experiment, trifluralin (0.5 and 1.0 mg:l) had no effect on embryo induction while oryzalin partly (0.125-0.25mg/l) or completely (0.5.mg/l) inhibited the formation of embryos. In the second experiment, higher concentrations of trifluralin increased the proportion of diploidized plants. Application of anti-mitotic drugs to microspores did generally not improve the overall production of haploid plants, which was higher in an untreated control.     

播前氟乐灵土壤处理减轻棉花枯萎病的效果

田间试验结果，除草剂氟乐灵４８％乳油以０．８６４ｋｇ／ｈｍ２作棉苗播前土壤处理，可明显减轻棉花枯萎病的发生，在现蕾期，施用氟乐灵后对感病品种沪棉２０１１和抗病品种中棉１２枯萎病株发病率的防治效果分别为４８．２５％～６９．４２％和４９．４１％～７０．５９％；病害严重度也明显下降，对沪棉２０１１和中棉１２的抑制作用分别为５５．９８％～６４．７８％和４６．３６％～７０．４５％。从棉花收获后进行的剖秆检查看，氟乐灵施用后不仅降低了枯萎病菌对棉花的侵染率，对沪棉２０１１和中棉１２的防治作用分别为１６．０２％和２６．８２％；而且也减轻了受侵棉花植株木质部的病变程度，对沪棉２０１１和中棉１２植株木质部病变的抑制作用分别为２２．０２％和３６．３３％，对施药２个月后土壤中枯萎病菌接种体密度的测定结果表明，氟乐灵并不影响土壤中枯萎病菌的接种体密度。综上所述结果，氟乐灵播前土壤处理可以减轻田间棉花枯萎病的发生，其原因是氟乐灵处理诱发了棉株对枯萎病的抗侵入和抗扩展能力。