Interaction of pesticides with p-glycoprotein and other ABC proteins: A survey of the possible importance to insecticide, herbicide and fungicide resistance

P-glycoproteins (p-gps) are ubiquitous membrane proteins from the ABC (ATP-binding cassette) family. They have been found in many animals, bacteria, plants and fungi and are extremely important in regulating a wide range of xenobiotics including pesticides. P-gps have been linked to xenobiotic resistance, most famously in resistance to cancer drug treatments. Their wide substrate range has led to what is known as “multidrug resistance”, where resistance developed to one type of xenobiotic gives resistance to a different classes of xenobiotic. P-gps are a major contributor to drug resistance in mammalian tumours and infections of protozoan parasites such as Plasmodium and Leishmania. There is a growing body of literature suggesting that p-gps, and other ABC proteins, are important in regulating pesticide toxicity and represent potential control failure through the development of pesticide resistance, in both agricultural and medical pests. At the same time, aspects of their biochemistry offer new hope in pest control, in particular in furthering our understanding of toxicity and offering insights into how we can improve control without recourse to new chemical discovery.     

白菜黑斑病空间分布型研究及杀菌剂筛选

通过对白菜黑斑病的空间分布型进行研究,结果表明:在发病初期,白菜黑斑病空间分布型为随机分布;在病害发生1代以后白菜黑斑病多为聚集分布;在病害发生后期,单株病斑数大于1 000的地块,白菜黑斑病可能成为均匀分布.通过室内杀菌剂的筛选,结果表明:退菌特对白菜黑斑病菌的毒力最强,福美双、代森锰锌(新万生)对白菜黑斑病菌的毒力也很强,杀毒矾、速克灵、百菌清对白菜黑斑病菌也有较好的毒力.     

Evaluation of environmental and management effects on Fusarium head blight infection and deoxynivalenol concentration in the grain of winter wheat

During the past decade European wheat (Triticum aestivum L.) crops were increasingly affected by Fusarium head blight (FHB) infection and high deoxynivalenol (DON) concentration in the grain. This is discussed to be primarily caused by the application of conservation tillage practices and, simultaneously, enhanced cultivation of host crops such as maize and wheat.

This study investigated the effect of several environmental and management factors on DON formation and, particularly, interactions between factors. Moreover, a methodology was developed to quantify the relative effect of single factors, and combinations of two or more management factors on the DON concentration in order to evaluate management strategies with regard to their potential effect on DON formation.

In 2001 and 2002, FHB infection of wheat and DON concentration in the grain was determined on eight sites of a long-term on-farm tillage experiment located in southern and eastern Germany. In addition, three-factorial plot trials varying tillage, cultivar, and fungicide application were conducted at Goettingen, Lower Saxony, in 2001 and 2002.

Based on these data, the severity of the effect of year, preceding crop, tillage, wheat cultivar and fungicide application was calculated as follows: mean DON value of the treatment with the highest DON concentration obtained in the study divided by the lowest treatment mean value. For each influencing factor the calculation was done on average of the other factors included. The following ranking order was obtained: annual variation of rainfall during wheat anthesis (4.4) = Fusarium infection/susceptibility of the preceding crop (wheat versus sugar beet, 4.3) = Fusarium susceptibility of the wheat cultivar grown (4.3–5.6) > soil tillage applied to cultivate wheat (1.3–3.4) ≥ fungicide application at anthesis of wheat (2.1). The relative effect of combinations of two or more management factors on the DON concentration can be calculated by multiplying severity factors. Limitations of this method are due to strong interactions between some of the factors (e.g. cultivar × fungicide application, cultivar × tillage). Within tillage treatments shallow mixing conservation tillage increased the DON concentration only slightly compared to conventional mouldboard ploughing, if previous wheat straw soil cover was reduced to about 30%. In this case, the severity of the effect of tillage was much smaller compared to year, preceding crop, and cultivar. Data also reveal that FHB infection values counted in the field do not give a reliable prediction of the DON concentration.

It is concluded, that choosing a resistant cultivar is a powerful tool to ensure a low DON concentration in wheat grain even under highly infectious conditions. This strategy enables farmers to make use of the benefits of conservation tillage and, simultaneously, produce high quality wheat grain.     

不同药剂和包装处理对甜樱桃生理、品质及贮藏性的影响

研究了不同药剂和包装处理对贮藏期间甜樱桃果实生理和品质变化的影响。试验结果表明，包装和药剂处理组合对控制果实腐烂，保持果实硬度和颜色，减缓维生素Ｃ和可滴定酸含量的下降速率，抑制乙烯和乙醇生成都具有较明显的效果。但是药剂和包装处理并不影响贮藏期间果实可溶性固形物的含量。生物 １号药剂与 ０．０４ ｍｍ厚加有ＴＢＺ的聚乙烯塑料薄膜袋配合对减缓果实衰老，减少果实腐烂和保持果实品质的效果最好。     

金叶女贞假尾孢病害的生物学特性和杀菌剂筛选

金叶女贞在6～7月和9～10月叶片上会出现许多不规则形状的病斑，俗称叶斑病，严重时会导致受害叶片早落。经研究其病原为假尾孢真菌Pseudocercospora sp．。通过人工接菌，观察了病害的症状、发病规律、培养特性、形态特征，以及温度、pH对菌丝体生长的影响。经室内杀菌剂筛选试验，用10g／L百菌清杀菌效果较好。     

香樟叶斑病病原菌的鉴定、菌丝生长速率及防治药剂筛选研究

目的 鉴定引起万州区香樟叶斑病的病原菌,明确病原菌菌丝生长特性,筛选出有效抑制叶斑病病原菌的杀菌剂,为该病的防治提供理论基础。 方法 采用组织分离法分离和纯化病原菌,用柯赫氏法则进行致病性测定,通过形态特征及ITS、tub2、GAPDH、ApMat多基因联合分析鉴定其病原菌种类;用菌丝生长速率法研究其菌丝生长特性,并进行杀菌剂的筛选。 结果 分离菌株在 PDA 培养基上培养3 d呈现灰褐色,边缘灰白色,后期有橘红色孢子堆出现,分生孢子呈长椭圆形、两端钝圆、透明无色、为独立的单胞,测量其孢子大小为(9.8～18.6) μm × (4.2～6.0) μm;用两种方法对优势菌株ZT-1进行致病性检验,均能引起香樟叶片发病;代表菌株ZT-1和ZT-5与胶孢炭疽菌（Colletotrichum gloeosporioides）聚在一支,支持率达100%;菌落的最适生长温度为28 ℃,最适pH值为6.0,马铃薯葡萄糖琼脂培养基利于菌丝生长,最适碳源和氮源分别为葡萄糖、甘氨酸,最适的光照条件是全黑暗;在化学和生物杀菌剂中,15%三唑酮可湿性粉剂、1%蛇床子素水乳剂的室内毒力较强,对C. gloeosporioides的抑制效果明显,其EC50值均小于10 μg·mL−1。 结论 C. gloeosporioides是万州区香樟炭疽病的病原菌,15%三唑酮可湿性粉剂可作为防治的杀菌剂。     

合欢溃疡病流行规律与综合防治技术研究

通过对合欢溃疡病危害症状、流行特点和发生规律开展详细调查研究,及8种药剂试验筛选,表明40％福美砷、50％福美双、70％甲基托布津和50％多菌灵治愈效果较好.通过刮除病斑后涂药和在病斑上直接涂药2种施药方法比较,前者取得更理想的防治效果,其中40％福美砷、70％甲基托布津100倍液药防治效果分别高出18.1％,10.4％.并实施营林综合防治方法,纯片林病害发生率最为严重,多行混交林带次之,单行纯林带较轻.     

竹材的防霉试验研究报告

本研究根据竹材防霉效力值,试验五种配方对竹材的防霉效果。结果:0.1％MBT和0.5％DP的防霉效果不次于2.5％BP(主剂为Na-PCP),尤其是MBT,使用浓度较低,高效,有可能代替氯酚类防霉剂;0.5％苯菌灵和3.0％季胺盐化合物的防霉效果较差,建议可用作竹材的短期防霉。     

The use of adjuvants to improve spray deposition and Botrytis cinerea control on Chardonnay grapevine leaves

Spray adjuvants have the potential to improve deposition by effecting uniform distribution of the active ingredient on plant surfaces. In order to study whether such a qualitative improvement of spray deposition would lead to improved disease control, a laboratory experiment was conducted on artificially inoculated grapevine (cv. Chardonnay) leaves. Prior to inoculation with Botrytis cinerea conidia in a spore settling tower, leaves were sprayed to pre-runoff with 1 mL of a mixture of fenhexamid, a fluorescent pigment, and one of 15 selected commercial adjuvants to manipulate the deposition quality of a specific quantity of spray. Following an incubation period of 24 h at high relative humidity, leaf discs were plated onto Petri dishes with paraquat-amended water agar and rated for development of B. cinerea from isolated leaf discs 11 d later. Spray deposition on leaves was assessed with a spray assessment protocol using fluorometry, photomicrography and digital image analyses. B. cinerea incidences on the upper and lower surfaces of water-sprayed leaves averaged 90.4% and 95.8%, respectively. Despite full spray cover of leaves, applications with fenhexamid alone did not completely prevent infection and resulted in 34.6% and 40.8% B. cinerea incidences on the upper and lower surfaces of leaves, respectively. Through the addition of certain adjuvants, B. cinerea incidences were significantly reduced (incidences of 2.9–17.1% and 10.0–30.8%, respectively), while some adjuvants did not differ from the fungicide only treatment, even though they might have improved spray deposition. In a histopathology study using epifluorescence microscopy, distinct differences were observed in conidium mortality (20.5% vs. 31.2%), germination (60.4% vs. 51.4%) and germ tube lengths (27.8 μm vs. 19.7 μm) between Hydrosilicote and Solitaire in combination with fenhexamid, even though both adjuvants effected similar quantitative and qualitative spray deposition. The study clearly demonstrated the potential of adjuvants to improve the bio-efficacy of a fungicide directly through improved deposition on grapevine leaf surfaces, although bio-efficacy might be influenced by adjuvant mode of action in some cases.     

几种杀菌剂对霉菌及香菇菌丝生长影响试验初报

本文就几种杀菌剂对霉菌及香菇菌丝和生长的影响进行了研究。经试验五种杀菌剂的不同浓度水溶液对所试四种霉菌的抑制作用亦不同，正常的使用浓度对香菇菌丝的生长速度多为减慢。