1%苦参碱·印楝素乳油防治小菜蛾的效果

<正>苦参碱是由中草药植物苦参Sophora flavescens的根、植株、果实经乙醇等有机溶剂提取制成的低毒植物源广谱杀虫剂,具有触杀和胃毒作用,对鳞翅目害虫、蚜虫、红蜘蛛等具有良好的防治效果[1-3]。害虫一旦触及该药剂,即麻痹神经中枢,继而使虫体蛋白质凝固,堵死虫体气孔,使害虫窒息而死[4]。而苦参碱直接在中药临床上应用已有多年历史[5]。印楝Azadirachta indica是原产于印度、缅甸的一种楝科     

观赏百合感染黄瓜花叶病毒后的超微病变研究

 黄瓜花叶病毒(Cymbidium mosaic virus,CMV)是雀麦花叶病毒科(Bromoviridae)黄瓜花叶病毒属(Cucumovirus)的典型成员,寄主范围极其广泛,能侵染1000多种的单、双子叶植物.该病毒可经75种蚜虫传播,有些分离物还可通过种子传播,是寄主植物最多、分布最广、最具经济重要性的植物病毒之一^[1].     

高毒力杀蚜真菌菌株筛选

蚜虫是同翅目胸喙亚目的一个重要类群 ,发生种类多 ,数量大 ,繁殖速度快 ,危害威胁重。到目前为止 ,全世界已知蚜虫近 4 0 0 0种 ,绝大多数是农作物害虫。蚜虫的危害不仅是直接刺吸植物汁液、分泌蜜露影响植物的光合作用和蒸腾作用 ,更主要的蚜虫是多种植物病毒的传播媒介。因此 ,开展蚜虫的防治工作意义重大。长期以来 ,蚜虫的防治主要是大面积使用化学农药。然而 ,单一使用化学农药 ,结果使大量天敌被杀伤 ,破坏了天敌与蚜虫的消长关系 ;蚜虫抗药性产生 ,且随着用药次数和用药量的增加而交替上升。另外 ,大量使用化学农药还存在环境污染和…     

庐山外来植物调查研究

[目的]为进一步了解庐山地区现有外来植物现状,掌握庐山外来植物数据,为庐山外来植物管理提供参考依据.[方法]运用线路踏查法进行野外调查并结合相关文献、标本资料,对庐山外来植物种类、生活型、 原产地、引入途径以及外来入侵植物种类进行研究.[结果]庐山外来植物共有89科309属448种:(1)菊科植物种类最多,有69种,约占总数的15.4％;(2)草本类外来植物有289种,占比最大,约64.5％;其次是乔木,83种,约占总数的18.5％;(3)原产于美洲的植物最多,有178种,约占总数的39.2％;其次是亚洲,有106种,约占23.3％;欧洲、非洲和大洋洲所占植物较少;(4)大部分外来植物为有意引种,引种目的主要为观赏;(5)庐山外来入侵植物有115种,占外来植物总数的25.67％.[结论]庐山的生态环境特殊,外来植物种类丰富,建议加强外来植物监管监测、科学引种,同时加大外来入侵植物危害宣传,完善外来入侵植物防治措施.     

椰枣叶斑病的病原鉴定

<正>椰枣树(Phoenix dactylifera L.)属多年生棕榈科热带植物，是阿拉伯国家重要的经济和粮食作物，果实被称为“沙漠面包”,具有较高的营养价值^[1-2]。 目前我国对椰枣的研究主要集中于椰枣化学成分分析^[3]、基因表达^[4]、植物组织培养^[5]、逆境胁迫^[6]等领域，对椰枣病害发生及病原菌种类鲜有报道。2020年11月—2021年6月，对海南省椰枣病害发生情况进行调查，     

新蚜虫疠霉感染致病蚜虫的空间分布特征及其理论抽样技术

[目的]探明新蚜虫疠霉的空间分布特点,为进一步研究蚜虫新蚜虫疠霉病害流行规律及田间释放病原菌防治桃蚜提供依据.[方法]调查甘蓝田新蚜虫疠霉感染致病桃蚜密度,采用Taylor幂法与Iwao回归法分析新蚜虫疠霉的空间分布特征.[结果]新蚜虫疠霉在甘蓝田呈聚集分布中的负二项分布,公共K值为2.87.Iwao直线回归方程拟合式为(m*)=0.12+1.36 m(R=0.99),Taylor幂公式为lg(v)=0.35+1.69 lgm (R=0.96).在不同季节,其空间分布的拥挤度差异显著(F=5.34,p＜0.01),7-9月平均拥挤度最高,而1-3月和10-12月最低.精度分别为0.1、0.2、0.3和0.5时的理论抽样数公式分别为n=430.26/x+138.30、n=107.56/x+34.57、n=47.81/x+15.37和n=17.21/x+5.53.当被新蚜虫疠霉感染罹病桃蚜密度较低,即低于每样方5头时,以模型n=17.21/x+5.53较为适宜,在较高密度,即每样方10头/株以上时,以模型n=107.56/x+34.57较宜.[结论]新蚜虫疠霉在甘蓝田均呈聚集分布中的负二项分布,聚集原因是新蚜虫疠霉生物学特性和环境因素.在6-8月,对该菌侵染蚜虫的总体理论抽样以抽查20株左右样方为宜,而在其他季节,抽查30株左右样方为宜.     

麦蚜发生规律及其防治研究

麦蚜是我县沿江圩田三麦上重要害虫,尤以晚小麦受害更重。对其发生危害及防治进行了初步研究,结果报道如下。 一、麦蚜种类和发生特点 沿江圩田三麦上蚜虫有二种:禾谷缢管蚜(又名黍蚜)Rhopalosiphum padi[Linnaeus]及麦长管蚜Macrosiphum avenae[Fabricius]。 定点田系统观察结果:前期以麦长管蚜较多,后期禾谷缢管蚜所占比例逐渐上升,最高可占到99％以上(见表1)。 大田调查,禾谷缢管蚜比例占59.2—96.4％。禾谷缢管蚜所以能占绝对优势,主要因为这种蚜虫生长势强,繁殖速度快,5月下旬单个蚜虫繁殖平均达45只,而麦长管蚜虫只有4.2只。     

即墨白庙芋头软腐病病原菌鉴定

<正>芋头(Colocasia esculenta (L.) Schoot)属天南星科芋属单子叶多年生草本植物,是世界上分布最广的作物之一^[1]。其地下块茎富含淀粉和各种微量矿物元素,在世界各地广泛种植,是一种深受人们喜爱的健康食品,并且在医药和观赏方面具有多种用途^[2-3]。我国是世界芋头种植大国之一,各地区均有种植^[4]。白庙芋头为山东即墨特产,有600余年的栽培历史。近年来,山东即墨地区爆发了严重的细菌性软腐病,严重影响白庙芋头的品质,     

甘蔗花叶病毒田间杂草寄主鉴定

正玉米矮花叶病1963年在美国俄亥俄州首次报道[1],我国1968年在河南省首次报道。甘蔗花叶病毒(Sugarcane mosaic virus,SCMV)是引起我国玉米矮花叶病的主要病原[2, 3]。根据基因组序列的系统发育分析,SCMV分为4个组,其中第I组分布最广,第IV组是新发现的一个强毒株系,近年来的发生呈上升趋势[4, 5]。SCMV属于马铃薯Y病毒属(Potyvirus),粒体为弯曲线状。其由蚜虫非持久性传播[6],能侵     

四丰山风景区鳞翅目昆虫多样性调查

[目的]为掌握四丰山风景区鳞翅目昆虫的分布情况,了解其分布规律,探究四丰山风景区鳞翅目多样性.[方法]自2021年4月至2021年9月,选取该风景区内林缘、草甸、湿地、灌丛等4种生境采样点,采用直接网捕法.[结果]采集鳞翅目昆虫1015头,经鉴定统计,共计54种,隶属于13科39属;对以上种类进行分析发现,4种生境样本...     

高原人体生理适应学理论在进藏旅游中的应用

青藏铁路的贯通运行,带来了国内外进藏旅游热.然而,青藏高原毕竟是世界屋脊,高海拔带来的低氧及其引发的高原疾病依然威胁着游客的身体健康.健康高原旅行是当前游客进藏旅游的基本前提,通过综合国内外高原医学工作者对高原医学生理学的研究成果,提出阶梯进藏旅游的方法.旨在对越来越多的短期赴西藏高原旅行的人群以正确的健康指导,从而减...     

稻瘟病菌对三环唑抗药性测定方法的建立

研究了稻瘟病菌对三环唑抗药性的测定方法,确定了保绿培养基的成分,建立了抗药性测定的标准化模型。4叶I心期将稻苗在三环唑系列浓度药液中浸根处理36 h,剪取稻苗叶段插于100 μg/mL苯并咪唑+0.5％水琼脂保绿培养基上,用孢子含量为10⁵个/mL的稻瘟病菌孢子悬浮液喷雾接种,保湿培养8 d后调查结果,计算EC₅₀值。该测定方法与小苗测定相比较结果更加稳定且灵敏度高,重复性好。     

白刺花(Sophoraviciifolia)适应土壤干旱的生理学机制

用盆栽的方法人工控制土壤干旱条件,研究白刺花天然实生幼苗适应土壤干旱的生理学机制。结果表明:随土壤含水量的减少,白刺花叶水势在胁迫前期下降缓慢,随胁迫时间的延长,水势大幅度下降。白刺花通过在叶片内积累大量渗透保护性物质可溶性糖和K ,增加细胞的保水力,维持细胞生长所需膨压。白刺花游离脯氨酸含量变化与水分关系不大,可溶性蛋白质含量随土壤含水量减少而下降,可能是水分胁迫下受伤害的表现。随土壤水分含量的减少,白刺花SOD的活性明显升高,POD活性不高但随胁迫时间延长其活性较稳定,CAT活性下降但幅度不大,且CAT活性变化趋势与POD活性相反,说明三个保护酶能够相互配合协同作用,降低膜脂过氧化程度,减少水分胁迫造成的伤害,提高质膜稳定性,维持细胞膜的完整性,表现出很强的抗旱适应性。     

Heritability of Ulmus minor resistance to Dutch elm disease and its relationship to vessel size,but not to xylem vulnerability to drought

Dutch elm disease (DED) is a vascular wilt disease that causes the occlusion and cavitation of xylem vessels. Therefore, it is hypothesized that those elms that are less vulnerable to cavitation by drought might be more resistant to DED. To test this hypothesis, the relationship between xylem vulnerability to cavitation and susceptibility to DED was examined in progenies of crosses between susceptible and resistant individuals of Ulmus minor. Hydraulic conductivity and xylem vulnerability curves were evaluated and anatomical features such as vessel size, length and grouping were measured. Next, elms were inoculated with Ophiostoma novo‐ulmi, the cause of DED, and pre‐dawn and midday water potentials, stomatal conductance and wilting percentages were assessed. Progenies of R × R crosses showed significantly lower mean wilting percentages (30–50%) than the progeny of S × S crosses (75%). Fifty percent conductivity loss was reached at c. ?1 MPa, pointing out a high vulnerability of this species to drought‐induced cavitation. Crown wilting percentage as a result of inoculation and xylem vulnerability to cavitation by water stress did not show any significant correlation. Nevertheless, significant differences in theoretical hydraulic conductivity and vessel size parameters (diameter, length and size distributions) were found among the tested progenies. Susceptible trees had significantly wider and longer vessels. Xylem structure of resistant elms seems to restrict pathogen spread rather than prevent cavitation.     

Contribution of Fimbrial and Afimbrial Adhesins of Xylella fastidiosa to Attachment to Surfaces and Virulence to Grape

ABSTRACT The role of fimbrial and afimbrial adhesins of Xylella fastidiosa in biofilm formation was assessed by visualization of cell aggregates of mutant strains after incubation on glass surfaces. FimA- or FimF- fimbrial mutants adhered as solitary cells at a slightly lesser frequency to glass surfaces than the parental strain; however, cell aggregates were not formed, unlike the wild-type strain. Conversely, whereas the XadA- and HxfB- nonfimbrial mutants also exhibited a much lower frequency of adherence to glass surfaces than the wild-type strain, most of the cells retained on the surfaces were in cell aggregates of different sizes, much like that of the parental strain. Neither fimbrial or afimbrial mutants formed a mature biofilm on the sides of flasks of broth cultures, unlike the dense biofilm formed by the wild-type strain. Although FimA- and FimF- mutants did not form cell aggregates on glass surfaces when incubated as individual strains, aggregates of a FimA- or FimF- mutant were observed when co-incubated with either a XadA- mutant or HxfB- mutant, respectively. These results are consistent with a model in which the fimbrial adhesins FimA and FimF are involved preferentially in cell-to-cell aggregate formation whereas the afimbrial adhesions XadA and HxfB preferentially contribute to initial cell binding to surfaces, whereupon further cell aggregation can occur. In each of five separate experiments, FimA, FimF, XadA, and HxfB mutants of X. fastidiosa all were less virulent to grape than the corresponding wild-type strain. Fimbrial and afimbrial mutants might produce a reduced biofilm within vessels of grape and, hence, be deficient in various cell-density-dependent traits required for movement through the plant and, thus, virulence.     

A grower-friendly method to transfer predacious mites to commercial orchards

The establishment of predacious mites in commercial orchards may be accelerated by the transfer of pruned wood in winter and summer from donor orchards to release orchards. Following winter pruning, 3-year-old and older wood is collected and transported as soon as possible in bundles to a release orchard for distribution. If the release orchard is composed of dwarf trees, then one or two bundles of 5 kg each are placed vertically at the base of the trunk of every tree in the block (0.5 to 1 ha); if the trees are of standard size, then four or five bundles used. Following summer pruning, annual shoots and suckers are distributed immediately in a release orchard composed of dwarf trees by placing 12–15 branches on the foliage of fruit-bearing branches; if the release orchard is composed of standard trees, then 50 branches are used. The pruned wood should have 20–25 leaves and not less than one predator per leaf. The release orchard should have a light infestation (two or three mites per leaf) of pest tetranychids. These phytophagous mites would serve as food and help establish the predators. The release orchard grower should develop a pest management program based on the same groups of pesticides used in the donor orchard. http://www.phytoparasitica.org posting Aug. 31, 2005.     

Note to chew on: insect damage to musical instruments

Insects have a diverse range of ecologies that leaves many pre‐adapted to exploiting manufactured products as food sources, including musical instruments. To review what is known and to make recommendations for preventing and managing insect damage to musical instruments, we conducted a systematic search and a narrative review of the area. Of 339 papers, only eight peer‐reviewed publications met the inclusion criteria, and all were on xylophagous insects causing damage to wooden instruments. To supplement this material, we report a case of damage to the key pads (composed of felt enclosed in fish buoyancy bladder skin) of a clarinet by carpet beetles (Anthrenus verbasci (Dermestidae)), the first reported case of non‐woody damage and the first instance of insect damage rendering an instrument unplayable. To avoid such damage, regular inspection of instruments is recommended, and rapid treatment of any insect infestations in the immediate environment that could extend to affecting stored instruments. Instruments themselves can be extremely expensive, and if insects are still present these should only be treated by an expert; instrument cases can be more easily dealt with by heat treatment (black plastic bag in the sun) or application of a residual insecticide. © 2020 Society of Chemical Industry     

Acknowledgment to Reviewers

Journal of General Plant Pathology -