人工栽培三叶木通褐斑病病原菌鉴定及防治药剂室内筛选

引起三叶木通果实及叶片褐斑的病原菌,经致病性测定、病害症状、病原菌培养性状和形态特征等比较,鉴定为半知菌亚门,丝孢纲,丝孢目,暗色菌科,链格孢属(Alternaria sp.)。经7种化学药剂对该病原菌室内毒力测定,结果表明,80%代森锰锌可湿性粉剂对该病原菌菌丝生长抑制作用最强,其EC50为8.28 mg/L。     

Characterisation of QoI‐resistant field isolates of Botrytis cinerea from citrus and strawberry

BACKGROUND: In 2004, field isolates of Botrytis cinerea Pers. ex Fr., resistant to strobilurin fungicides (QoIs), were first found in commercial citrus orchards in Wakayama Prefecture, Japan. Subsequently, QoI‐resistant isolates of this fungus were also detected in plastic strawberry greenhouses in Saga, Ibaraki and Chiba prefectures, Japan. Biological and molecular characterisation of resistant isolates was conducted in this study. RESULTS: QoI‐resistant isolates of B. cinerea grew well on PDA plates containing kresoxim‐methyl or azoxystrobin at 1 mg L^?1, supplemented with 1 mM of n‐propyl gallate, an inhibitor of alternative oxidase, whereas the growth of sensitive isolates was strongly suppressed. Results from this in vitro test were in good agreement with those of fungus inoculation tests in vivo. In resistant isolates, the mutation at amino acid position 143 of the cytochrome b gene, known to be the cause of high QoI resistance in various fungal pathogens, was found, but only occasionally. The heteroplasmy of cytochrome b gene was confirmed, and the wild‐type sequence often present in the majority of resistant isolates, indicating that the proportion of mutated cytochrome b gene was very low. CONCLUSION: The conventional RFLP and sequence analyses of PCR‐amplified cytochrome b gene are insufficient for molecular identification of QoI resistance in B. cinerea. Copyright © 2009 Society of Chemical Industry     

防治香蕉叶斑病杀菌剂的应用进展

化学药剂是防治香蕉叶斑病的主要手段之一。本文综述了防治香蕉叶斑病杀菌剂的应用研究进展,重点介绍了这些杀菌剂的类型尧作用机理、化学结构、防治效果及在我国的登记情况等。     

几种杀菌剂对苹果斑点落叶病的田间防效研究

比较了5种不同药剂对苹果斑点落叶病的防效。结果表明:在田间推荐使用浓度下,5种药剂对苹果斑点落叶病均有很好的控制效果。30%己唑醇悬浮剂85 g/hm2、10%苯醚甲环唑微乳剂85 g/hm2和70%丙森锌.多菌灵可湿性粉剂1700 g/hm2的防治效果较好,在秋稍生长期和整个生育期对苹果斑点落叶病的防效均在80%以上;两种保护性杀菌剂,80%代森锰锌可湿性粉剂1360 g/hm2和70%丙森锌水分散粒剂1487.5 g/hm2的防效相对较低。     

竹毛壳菌对六种杀菌剂的耐药性测定

为了了解竹毛壳菌对化学杀菌剂的敏感程度,开发出对化学杀菌剂有抗性,生防效果稳定的遗传工程菌,采用常见化学杀菌剂进行了室内毒力测定。结果表明,该毛壳菌在不含杀菌剂的PSA培养基上能正常生长,但当PSA培养基中含0.10,0.25,0.50,1.00,2.00mg·L^-1不同浓度的6种杀菌剂时,毛壳菌表现出不同程度的耐药性。毛壳菌对甲基托布津和代森锰锌更为敏感,有效抑制中浓度EC50分别为1.2572mg·L^-1和1.9138mg·L^-1,而对地菌灵抗性最强,有效抑制中浓度EC50为779.4711mg·L^-1,敏感程度依次为甲基托布津〉代森锰锌〉多菌灵〉三环唑〉百菌克〉地菌灵。     

Enzyme activities in vineyard soils long-term treated with copper-based fungicides

Copper-based fungicides have been applied in vineyard soils for a long time, which has resulted in increasing soil Cu concentration. However, information relating to non-target effects of these fungicides on microorganisms of these soils is scarce. The aim of this study was to determine the potential enzyme activities of vineyard soils in relation to Cu content and evaluate the potential risks of long-term application of Cu-based fungicides. For this purpose, a wide range of soil samples, having different total, exchangeable and bioavailable Cu contents, were collected from six regions of quality wines located in the NW Iberian Peninsula, and the activity of dehydrogenase, β-glucosidase, urease and phosphatase were measured. Overall, the results obtained indicate adverse effects of Cu on dehydrogenase, β-glucosidase and phosphatase activities and an inconsistent effect on urease activity. Threshold Cu concentrations at which changes in the enzyme activities became evident were 150-200 mg total Cu kg⁻¹ and 60-80 mg bioavailable Cu kg⁻¹.     

重金属铜在甘蔗体内的吸收及对甘蔗产量和品质的影响

通过盆栽试验,研究重金属Cu在甘蔗体内吸收、积累规律及对甘蔗产量和糖分的影响情况。结果表明,根、茎、枯叶、梢头对Cu的积累能力总体表现为根茎枯叶梢头,甘蔗各部分器官Cu含量随外源投放的Cu浓度而增加,呈显著的正相关。少量的Cu会使甘蔗明显增产,但胁迫或过量对甘蔗的生长和生物量的影响不明显。Cu过量对甘蔗品质的影响表现在出汁率、还原糖的增加和纤维分的降低,适当地施Cu会增加甘蔗的产糖量,但过多会减低甘蔗的产糖量。     

6种杀菌剂对3种禾草病害的防治研究

为了筛选用于禾草病害防治的高效、低毒、低残留的杀菌剂,本试验选用6种常见的杀菌剂对3种禾草病原菌进行了室内毒力测定及田间试验。结果表明,苯菌灵对褐斑病菌和炭疽病菌的EC₅₀值分别是0.492 4,0.446 6 mg/L,多菌灵对禾草云斑病菌的EC₅₀值是0.413 0 mg/L,其抑制作用最好。田间药效试验表明,50%苯菌灵WP(750 g/hm²)防治禾草褐斑病和禾草炭疽病、25%多菌灵WP(750 g/hm²)防治禾草云斑病有各自较好的防治效果,在药后10 d的防效分别是75.40%,72.06%和76.97%。室内毒力测定与田间药效试验结果表现一致,且6种供试药剂防治3种禾草病害具有明显的时效性。     

饲料铜含量对亚硝酸盐胁迫下斑节对虾血细胞的影响

研究了饲料铜离子含量对亚硝酸盐胁迫下斑节对虾（Penaeus monodon）血细胞参数的影响。向斑节对虾投喂不同铜离子添加量（0,10,25,40,55和110 mg/kg）的饲料8周后,进行24 h 的20 mg/L亚硝酸氮胁迫,取样测定对虾的血细胞总数（THC）、血细胞活性氧（ROS）含量和血细胞凋亡率。结果显示,经亚硝酸盐胁迫后,25-55 mg/kg饲料组对虾能保持较高的THC,以及较低血细胞ROS含量和凋亡率;110 mg/kg饲料组对虾的THC最低,血细胞ROS含量和凋亡率均最高。这些结果表明饲料中添加25-55 mg/kg的铜离子能有效降低亚硝酸盐胁迫对血细胞造成的氧化损害,但过量添加（110 mg/kg）反而对血细胞造成更为严重的损害。     

长白山区人参锈腐病发生危害调查及杀菌剂田间药效试验

[目的]人参是我国传统名贵中药材,锈腐病是人参主要根部病害,生产上缺乏防治该病的有效药剂。本文对长白山区人参锈腐病发生危害进行调查,并选用新型杀菌剂对人参锈腐病菌的毒力及田间防效进行了测试,以期为生产上安全高效防治该病提供理论依据。[方法]采用菌丝生长速率法测定11种杀菌剂对人参锈腐病菌的毒力,并进行田间防效试验。[结果]室内毒力测定结果表明10%世高WG、18.7%凯特WG和60%百泰WG对人参锈腐病菌毒力最强,其EC50值分别为1.19mg/L、20.56 mg/L和27.77 mg/L。田间试验结果表明10%世高WG、18.7%凯特WG和60%百泰WG对人参锈腐病防效达50%以上。[结论]人参锈腐病发病盛期为6月上旬至7月下旬,10%世高WG、18.7%凯特WG和60%百泰WG是目前防治人参锈腐病的有效药剂。