吩嗪-1-羧酸双酰肼衍生物的合成、杀菌活性及韧皮部的输导性研究

天然产物吩嗪-1-羧酸（PCA,申嗪霉素）及其衍生物吩嗪-1-甲酰肼具有独特的化学结构和优良的杀菌等生物活性,但均没有韧皮部输导性。本文以具有抑菌活性的吩嗪-1-羧酸和具有韧皮部输导性的马来酰肼为先导化合物,将马来酰肼中的双酰肼结构引入到吩嗪-1-羧酸中,设计、合成了17个新化合物,其结构均经过核磁共振氢谱、高分辨质谱及X-射线单晶衍射分析确证。初步生物活性测试表明:大部分目标化合物在50 mg/L下对水稻纹枯病菌Thanatephorus cucumeris表现出中等偏上的抑制活性,其中化合物6m的抑制率达92%。但输导性研究结果显示,目标化合物没有明显的韧皮部输导性。     

Accumulation patterns and fungicidal effect of carbendazim and thiabendazole in peanut plants after soil injection

Carbendazim and thiabendazole applied to the rhizosphere of peanut plants by injection into the soil at doses of 0.1, 0.5 and 2.5 g per 1 m row, accumulated in the leaves during the first week after treatment, the concentrations being related to the doses applied. Two weeks after treatment the concentrations of both fungicides dropped sharply. During the rest of the season, whilst the concentration of carbendazim in the high-dose treatment was 0.1 mg/kg fresh weight, the concentration of thiabendazole increased from 0.1 to 2.0 mg/kg and remained at this level until harvest. At the end of the growing season treated plants were less infected with Cercospora leaf spot (Cercospora per sonata) than the untreated control, thiabendazole affording better protection than carbendazim. Plants treated with the highest dose of thiabendazole were the only ones that did not wilt, even though infected. Laboratory studies of the adsorption of these fungicides on soil revealed that carbendazim is less adsorbed and also less persistent than thiabendazole.     

Foliar application of benzovindiflupyr shows non‐fungicidal effects in wheat plants

BACKGROUND

The fungicide benzovindiflupyr belongs to the class of succinate dehydrogenase inhibitors (SDHIs). Certain SDHIs have shown plant physiological effects, so‐called secondary effects, that appeared to be related to the plant water status. Therefore, the effect of benzovindiflupyr on transpiration of leaves and whole wheat plants was studied under controlled conditions. Furthermore, wheat yield trials under controlled and natural drought stress in the field were conducted.

RESULTS

Transpiration of detached wheat leaves was reduced by benzovindiflupyr in a dose‐dependent manner. Similarly, whole‐plant transpiration decreased for several days following application of this fungicide. In 16 field trials under drought stress conditions that were classified as disease‐free, treatment of wheat plants at the flag leaf stage or at heading with benzovindiflupyr showed a grain yield increase (+5.2%; P ≤ 0.01) that was partially attributed to an increased thousand‐grain weight.

CONCLUSIONS

Water saving during pre‐anthesis as a result of benzovindiflupyr application may be associated with better seed setting and filling under dry field conditions in wheat. The results of this research provide new insights into secondary effects of SDHIs that lead directly to yield improvements. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Metabolism and selectivity of rice herbicides in plants

Chemical weed control with effective and highly active herbicides has been very useful and convenient means. It has contributed to stable crop production and is labor saving. Recent herbicides have had characteristics such as high effectiveness without causing environmental pollution or harmful effects, and appropriate herbicides having high activity, low toxicity, high selectivity and being non-persistent have been developed. The metabolism of rice herbicides used mainly in Japan, such as sulfonylurea, chloroacetamide, acylamide, urea, thiocarbamate, pyrazole, triazine, diphenyl ether, phthalimide, phenoxy, aryloxyphenoxypropionate, etc., is reviewed, and its involvement in selectivity is also discussed. The metabolism of herbicides is closely related to their activity and selectivity. Differential herbicide metabolism in plants is a contributing factor of selectivity between crops and weeds. Chemicals that are more detoxified in crops and/or more activated or less detoxified in weeds are considered as being effective and selective herbicides. The metabolism of various types of rice herbicides includes: oxidative reaction (ring and chain hydroxylation, O - and N -dealkylation), hydrolysis and subsequent glucose conjugation, and glutathione conjugation in rice. These detoxicative activities are much higher in rice than weeds in paddies, and this leads to the selectivity of herbicides. Enzymes, oxidase, P-450 mono-oxygenase, esterase, acylamidase, glucosyl transferase, glutathione transferase, etc., play important roles in herbicide metabolism and selectivity.     

二氯喹啉草酮在水稻植株上的消解动态及其在稻秆、稻谷和土壤中的最终残留

二氯喹啉草酮是经中国农业农村部批准登记的茎叶处理除草剂,迄今为止对其潜在的环境污染尚未见报道。本研究建立了一种采用QuEChERS前处理方法结合高效液相色谱-串联三重四极杆质谱 (HPLC-MS/MS) 联用技术检测二氯喹啉草酮在水稻植株、稻谷和土壤中残留的方法,并采用该方法测定了二氯喹啉草酮在水稻植株中的消解动态和最终残留。结果表明:二氯喹啉草酮的进样质量浓度与其峰面积间呈良好的线性相关,R2>0.99;其在植株、土壤、田水、稻壳和糙米中的平均回收率在78%~99%之间,相对标准偏差 (RSD) 在3.9%~11%之间,在植株、土壤、田水、稻壳和糙米中的最低检测浓度 (LOQ) 均为0.002 mg/kg。二氯喹啉草酮在水稻植株中的消解半衰期为6.7~12.8 d。以有效成分900~1 350 g/hm2的剂量于水稻苗期施用1次,在施药96 d后采集的土壤、稻壳和糙米中均未检测出二氯喹啉草酮。本研究结果可为水稻中二氯喹啉草酮最大残留限量值和田间使用规范的制定提供参考。     

Suppression of rice blast by phylloplane fungi isolated from rice plants

Rice phylloplane fungi were evaluated for their potential as biocontrol agents for rice blast disease caused by Magnaporthe grisea. A total of 1923 fungal isolates were obtained from rice plants in fields at Ishigaki and Iwama and from potted plants placed in a cedar woods in Iwama as bait. Although 82.9% of isolated fungi could not be identified, species of Epicoccum were the most prevalent among identified isolates. Of the 1923 isolates, 967 were randomly selected for screening against rice leaf blast. Nine isolates (MKP5111B, MKP5112, J2JMR3-2, K2J131-2, I5R3-1, NOP541, K1KM134-1, NOP5112, MKP33222) suppressed the disease when a conidial or hyphal suspension of both the phylloplane fungus and pathogen were simultaneously used to inoculate rice plants cultured in pots in a growth chamber. Five of the isolates originated from potted plants in the woods and four from Ishigaki, a subtropical island. Five (MKP5111B, MKP5112, NOP541, NOP5112, MKP33222) of the nine isolates strongly suppressed conidial germination of M. grisea (0.7%) and formed inhibition zones (3–5mm width) in dual cultures with the pathogen. Methanol extracts from the isolates also inhibited mycelial growth of the pathogen. These results suggest that the five isolates produced antibiotic(s). These five isolates are likely identical or closely related fungal species because the sequence of their ITS regions were 100% similar. ITS sequence analysis also suggested that J2JMR3-2 was associated with a species of Fusarium. Under field conditions, J2JMR3-2 reduced both leaf and panicle blast severity, and three other isolates (MKP5111B, K1KM134-1, K2J131-2) suppressed leaf blast in one of the three experiments.     

Propanil metabolism in rice: A comparison of propanil amidase activities in rice plants and callus cultures

Propanil amidase is an enzyme found in rice, which hydrolyzes the herbicide 3,4-dichloropropionanilide, propanil. The activity of the enzyme as measured in rice plants was found to be two to four times greater in plants with four leaves than in plants with fewer than four leaves. The higher amidase activity of the four-leaf plants was localized in the unexpanded leaves.Rice root callus suspension in cultures also demonstrated propanil amidase activity. In vivo experiments indicated that the herbicide was metabolized by the tissue culture. Propanil amidase activity as determined in vitro, however, was detected only after the culture had developed to late stationary phase.     

Metabolism of some sterol inhibitors in fungi and higher plants,with special reference to the selectivity of fungicidal action

The metabolism of triforine, chloraniformethan, the α-(pyrimidin-5-yl)benzhydryl alcohols (fenarimol, nuarimol and triarimol), the trityl-azoles (fluotrimazole and clotrimazole), and the morpholine types of sterol inhibitors is reviewed; the metabolism of the azolyl-alkane derivatives (mainly triadimefon and triadimenol) is discussed in detail. Redox and hydrolytic reactions are of primary importance. Enzymic inactivation may be one factor influencing fungicide selectivity. Metabolism is the dominant factor of selectivity if it represents the activation process, as with triadimefon. Transformations in higher plants do not differ significantly from those occurring in fungi, except that factors such as the formation of conjugates with natural compounds of plant tissues also play a role, as with triforine and triadimenol. The selectivity of fungitoxic action may be influenced by metabolism both in the host plant and the pathogen.     

Transgenic rice plants that over-express the mannose-binding rice lectin have enhanced resistance to rice blast

Mannose-binding rice lectin (MRL), which is almost identical to the salt-induced protein SalT, binds to mannose and glucose residues. Expression of the MRL gene in response to infection with Magnaporthe oryzae, the rice blast fungus, was stronger in the incompatible interaction than in the compatible. Transgenic rice plants that constitutively over-expressed MRL strongly suppressed the growth of invasive hyphae of the fungus on leaf sheaths and the development of typical susceptible-type lesions on leaf blades, but did not affect penetration by the fungus in comparison with the wild-type. On a polycarbonate plate, purified recombinant MRL inhibited conidial attachment and appressorium formation but not conidial germination. These results suggest that MRL may play an essential role in disease resistance by suppressing development of M. oryzae in situ.     

Effects of brassinolide on the growing of rice plants

Brassinosteroids are plant steroid hormones that are essential for plant growth. When germinated rice seeds were treated with brassinolide (BL), stems were elongated and root spiral formation was observed at 5 nM of BL. Such root spiral formation was not induced by other plant hormones such as auxin and gibberellin. Since weak non-steroidal brassinolide-like compound (NSBR1) also induced spiral formation, this root spiral induction can be used as the index in the search for BL-like compounds.     

枯草芽胞杆菌GB519在水稻植株中的定殖及对稻瘟病田间防效

枯草芽胞杆菌GB519是一株具有广谱抑菌活性的生防菌株。本研究利用绿色荧光蛋白标记的菌株GB519-GFP处理水稻种子、根和叶片,结合激光共聚焦显微镜观察和抗生素平板回收检测的方法,探究其在水稻根茎叶中的定殖动态。结果显示：经GB519-GFP发酵液处理水稻种子、根和叶片后,菌株均可内生定殖于植株的表皮、皮层和维管束中,表明其可在水稻植株内迁移和定殖。GB519-GFP在处理部位的定殖量通常呈现先减少后增多的趋势,非处理部位3～5 d后即可检测到标记菌株。浸种处理,3 d后在幼芽中可检测到标记菌株;20 d后在根中的菌量最多,达5.7×10⁵ cfu/g。灌根处理,1 d后根中菌量为5.4×10⁵ cfu/g; 20 d后根、茎和叶中菌量均达到最大值;处理80 d后,根中定殖数量仍达1.9×10⁵ cfu/g。叶面喷施处理,1 d后叶片菌量为4.2×10⁵ cfu/g; 20 d后叶片菌量达4.4×10⁵ cfu/g。不同处理方法在各部位的定殖量几乎均在处理20 d后达到峰值。...     

二化螟田间为害株率与为害丛率间的关系

通过不同调查者调查相同稻田内二化螟为害的枯鞘、枯心和白穗等受害稻株,分析平均受害株率和平均受害丛率的关系。结果表明,“平均受害丛率”在不同调查者之间的误差小于“平均受害株率”。受害株率和受害丛率之间呈正相关的关系,当受害丛率小于60%时,受害株率与受害丛率的相关系数超过0.91,用受害丛率可以较准确地估计受害株率。     

Unravelling the physiologic and metabolic action of thiamethoxam on rice plants

We investigated some physiological and biochemical effects promoted by the insecticide thiamethoxam on rice crops. Two experiments were carried under pest-free conditions, in the greenhouse, with thiamethoxam at doses of: 0, 17.5, 35.0, 70.0 and 105.0 g a.i. per 100 kg of seeds. In order we check the physiology, biochemistry and production. In the first experiment thiamethoxam alter the content of photosynthetic pigments, as well as the enzymatic activity of phenylalanine ammonia-lyase, and in the second experiment this molecule modified the root development and nitrate reductase activity in rice plants. We believe that the thiamethoxam has potential to change the primary and secondary metabolism of rice plants, characterizing as a bioactivator.     

三唑类杀菌剂对水稻药害机理及解决方案

三唑类杀菌剂(triazole fungicide, TFs)是一类广谱、高效、低残留、长效、内吸传导性好,同时具有保护和治疗作用的新型杀菌剂,对真菌性病害有较好的防控效果,在作物病害防治上被广泛应用。三唑类杀菌剂在防治水稻中、后期真菌性病害上取得了极好的防效,是应用量较大的杀菌剂之一。但由于三唑类杀菌剂使用不当,在生产上造成了大量的药害实例,导致水稻减产或绝收,同时引起了一些社会问题,需要引起高度重视。本文在作者多年的调查和研究基础上结合相关文献资料,阐述了三唑类杀菌剂的分类、使用方法、作用机制,对水稻产生药害的原因、症状表现和机理,使用三唑类杀菌剂时避免发生药害的措施及药害发生后的补救方法。     

水分对旱稻土壤及植株中主要营养元素含量的影响

在防雨棚池栽条件下研究了不同水分处理下土壤矿质元素的释放及旱稻植株对矿质元素的吸收利用特点。结果表明：土壤水分对土壤N、P、K含量及植株养分吸收存在明显影响。随着土壤水分含量的提高,土壤硝态氪含量显著下降,氨态氪含量显著上升;磷素在低水分处理下先升高后基本保持较高水平,而在高水分处理下有一个升降升的变化过程;钾素在65％、100％水分处理下在分蘖中后期显著大于其它水分处理,而在分蘖前期各水分处理都有一个先降后升的变化趋势。在植株对矿质元素的吸收上,100％水分处理下植株体内的全氮含量一直呈下降趋势,65％、75％处理下磷素变化呈“U”型,其余各处理下植株体内的N、P、K含量都呈W型变化。随土壤含水量的增加,旱稻植株对N、P、K的吸收总量均增加。     

杀菌剂生物测定技术的发展

概述了杀菌剂生物测定的发展历史,探讨了离体、活体和组织筛选的常规生物测定技术,以及高通量筛选方法,同时从多个角度阐述了杀菌剂生物测定技术的发展趋势。     

杀菌剂生物测定技术的发展

概述了杀菌剂生物测定的发展历史,探讨了离体、活体和组织筛选的常规生物测定技术,以及高通量筛选方法,同时从多个角度阐述了杀菌剂生物测定技术的发展趋势。     

氘标记稻瘟酯的合成及其杀菌活性

氘标记农药作为探针或者内标在农药代谢、毒理研究或者农药残留分析中发挥着重要作用。由于动力学同位素效应,C-D键比C-H键更为稳定,因此氘标记农药可能具有更长的半衰期,以及对非靶标生物更小的毒性。稻瘟酯是一种对水稻恶苗病和稻瘟病有良好防治效果的农用杀菌剂。本项研究利用单电子转移还原氘化反应和氘标记中间体,成功合成了4个不同位点被选择性氘代的稻瘟酯,其中3个化合物未见文献报道,并对其进行了杀菌活性测试。离体杀菌活性测试结果显示,上述4种氘代稻瘟酯对水稻稻瘟病菌和水稻恶苗病菌均具有良好的生物活性,与未被标记的稻瘟酯无显著差异。氘标记稻瘟酯未来可作为代谢、毒理研究的探针及农药残留分析中的内标。     

取代苯甲酸酯类化合物的合成与杀菌活性

以取代苯甲酸和异戊醇为原料,合成了14个未见文献报道的取代苯甲酸酯类化合物,其结构均通过红外光谱、核磁共振氢谱和气相色谱-质谱联用（GC-MS）确证。生物活性测定结果表明:14个新化合物对灰霉病菌Botrytis cinerea、稻瘟病菌Piricularia oryzae和纹枯病菌Rhizoctonia solani的活体杀菌活性均好于离体杀菌活性,尤其是化合物3j在500 μg/mL下对黄瓜灰霉病的活体防效达96.4%,3e（500 μg/mL）对水稻稻瘟病的活体防效为96.3%。