Elektronenmicroscopische waarnemingen over de zoösporen uit de zomersporangia vanSynchytrium endobioticum (Schilb.) Perc

Summary Electron microscope observations on the soral zoospores ofSynchytrium endobioticum revealed, besides nuclear substance, the presence of a crateriform cavity in the zoospore body. Probably this cavity corresponds with the vacuole which contains oil in the living zoospore. The flagella are cylindrical and they have a whiplash tip. Faint longitudinal striations can just be detected in some of the flagella. A slight terminal swelling on the end of the whiplash is occasionally found. Several flagella, showed fibrillar disintegration. Making elevent fibres in all, there are two long central strands and nine shorter peripheral strads. A fine line running along the centre of some fibres indicates that probably each fibre contains two subfibres.     

猪殃殃Galium aparine L.var.tenerum(Gren.et Godr.)Rchb.发生规律观察

猪殃殃是我省分布广泛,危害严重的麦田恶性杂草。近年来,发生数量和危害面积还在不断上升,是麦子增产的障碍之一。笔者从1979年秋播开始对其生物学特性和发生规律作了调查观察,现将观察结果简报如下: 一、分布特点猪殃殃的分布和土质有很大关系,据在本地区9个县46个公社调查1561亩麦田(代表面积一万七千余亩)每平方尺发生10株以上的危害面积,沙土地区占调查面积的12.2％,粘土     

Colonization of rose by Sphaerotheca pannosa (Wallr.) Lév. var. rosae Wor.

Colonization of rose by powdery mildew (Sphaerotheca pannosa) is described in terms of mycelium growth, conidiophore production and sporulation in time. The data used are gathered during different years, put together and treated by means of graphic models. Colonies could be separated into fast and slow growing colonies. Colonies initiated on leaves of increasing age showed a decreasing growth rate. Production of conidiophores and conidia started on the same day, and the relative activity of conidiophore production reached its maximum 6 days after the end of the latency period, followed 1 day later by the maximum activity of conidium production. Both conidiophore and conidium production continued for a long time at a low level. The effect of leaf age on conidiophore production found expression in differences in production rate during the first days of colony development and in final production levels. Observations on naturally infected leaves in an outdoor experiment showed a rapid decrease of sporulation on leaves of 10 days and older. Highest percentages of sporulating leaf area were observed on leaves between 7 and 10 days old.     

Zum Auftreten der Robinien-Miniermotte,Phyllonorycter robiniella (Clem.) und der Ro?kastanien-Miniermotte,Cameraria ohridella Desch. & Dim. (Lep., Gracillariidae) in Südtirol

Zusammenfassung  An 2 Gracillariiden,Phyllonorycter robiniella undCameraria ohridella, wird gezeigt, wie rasch importierte Sch?dlinge sich ausbreiten k?nnen: Die RobinienblattmotteP. robinella wurde in Südtirol erstmals 1991 festgestellt und trat 1996 bereits in Massenbefall bei Brixen an Robinien auf.—Die Ro?kastanienminiermotteC. ohridella war hier erstmals 1992 im Pustertal bei Toblach festgestellt worden (Butin & Führer, 1994). Neueste Untersuchungen im Herbst 1997 zeigen, da? sie nun bereits im gesamten Eisacktal zwischen Franzensfeste und Bozen an Ro?kastanien (Aesculus hippocastanum) verbreitet ist (Tab. 1); hingegen wurde im Etschtal südlich und westlich von Bozen bisher noch kein Befall festgestellt.

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On the occurrence of the robinia-leafminer,Phyllonorycter robiniella (Clem.) and the horse-chestnut- leafminer,Cameraria ohridella Desch. et Dim. (Lep., Gracillariidae) in South Tyrol

The examples of two species of Gracillariidae,Phyllonorycter robiniella andCameraria ohridella, show how fast the expansion can take place: The robinia-leafminerP. robiniella was first noticed in South Tyrol in 1991 and an outbreak occured on False Acacias near Brixen, already in 1996.—The horsechestnut leafminerC. ohridella was first noticed in the Pusteria Valley near Toblach-Dobiacco, in 1992 (Butin & Führer, 1994). The latest research, of autumn 1997, shows that they are now distributed on Horse Chestnut Trees (Aesculus hippocastanum) in the whole Isarco Valley, between Fortezza and Bozen-Bolzano (Tab. 1), whereas in the Adige Valley at south and west of Bolzano no occurrence could be found as yet.

     

Enkele waarnemingen over versmelten van zoösporen bij Phytophthora infestans (Mont.) de Bary

Summary Zoospores ofPhytophthora infestans were seen to fuse in pairs. Generally within 30 min. after zoospore discharge, fusion started by the formation of a connection between touching zoospores. Gradually the connection became shorter and thicker (fig. 1,2 and 3), and within 30 min. the two zoospores united to form a spherical body (fig. 4). The flagella were thrown off just before the compound zoospore assumed the spherical shape. The compound zoospores germinated by a germ tube within 30 min. after their formation. The analogy withCritopoulos' observations on zoospore fusion inP. capsici is discussed.     

核盘菌(Sclerotinia sclerotiorum (Lib.) de Bary)侵染抑制黄瓜光合作用的机理

 以津春四号黄瓜(Cucumis sativus L. ‘Jinchun 4’)为实验材料,通过同时测定黄瓜叶片叶绿素荧光快速诱导动力学曲线和对820 nm光的吸收曲线,以及过氧化氢含量和过氧化氢酶(CAT)活性的变化,研究了核盘菌(Sclerotinia sclerotiorum(Lib.)de Bary)侵染黄瓜叶片后,对光系统Ⅰ(PSⅠ)和光系统Ⅱ(PSⅡ)功能的影响,并分析了核盘菌侵染后,两个光系统之间的相互影响。结果表明,核盘菌侵染叶片后,叶片过氧化氢(H₂O₂)含量升高,膜脂过氧化的程度加剧,叶片放氧能力下降,快速叶绿素荧光诱导动力学曲线发生变化。核盘菌侵染严重伤害了PSⅡ供体侧(放氧复合体)、受体侧以及反应中心的活性,并且降低PSⅠ最大氧化还原能力(△I/Io)。核盘菌侵染黄瓜后,抑制了CAT的活性,导致过量活性氧的积累,直接伤害了光合机构PSⅠ和PSⅡ的功能;对PSⅠ的伤害抑制了PSⅡ电子向PSⅠ的传递,进一步加剧了PSⅡ的伤害程度,导致更多过剩激发能产生,造成恶性循环,这是核盘菌抑制黄瓜光合作用的主要原因。     

豚草(Ambrosia artemisiifolia L.)

豚草又名艾叶破布草和豕草，学名：Ambrosia artemisiifolia L．英文俗名：Common ragweed，Bitterweed，Blackweed，Hay—fever Weed，属双子叶植物纲菊科豚草属。     

毒麦(Lolium temulentum L.)

毒麦学名：Lolium temulentum L．；英文俗名：Poison Ryegrass，Bearded Ryegrass，Darnel；属单子叶植物纲(Monocotyledoneae)莎草目(Cyperales)禾本科(Poaceae)黑麦草属(Lolium L．)。俗名黑麦子、迷糊、小尾巴麦子。     

列当(Orobanche spp. and Phelipanche spp.)种子的采集与预处理方法

列当(Orobanche spp.and Phelipanche spp.)是一种在世界范围内危害严重的根寄生杂草,防除列当的研究也越来越多。正确地采集和预培养列当种子是获得正确防除列当研究结果的前提。列出了大田正确采集列当种子的方法,以及对采集到的种子进行过筛提纯、加洗洁精和吐温20清洗后,再表面消毒和预培养,并通过发芽试验检验此方法的可行性。结果表明,经过处理的向日葵列当、瓜列当种子的发芽率最高分别为54.4%、59.1%。此方法可以应用于列当的采集和预处理过程中,可为列当研究和防除提供参考。     

对于柿和君迁子角斑病(Cercospora kaki Ell.&Ev.)的研究

 柿樹虽然是亚热带果樹,但在我国分布很广,南自海南島,北迄河北省長城一带都有柿的栽培,从数量上看,有許多省如河南、河北、山东、陝西、湖北等,柿的栽培都占果樹栽培中重要地位。     

Bekämpfung von Epilachna vigintioctopunctata (F.) und Spodoptera litura (F.) mit Silikaten

The present work deals with the insecticidal efficacy of different modified natural silica products against the field pests Epilachna vigintioctopunctata (F.) and Spodoptera litura (F.). The substances “Fossil Shield^® 90.0s”, “Advasan^®” as well as different formulations of a silica-derived substance named “AL06” (developed in the section Urban Horticulture, Humboldt-University Berlin) were dusted into gauze-covered cages. In each cage, test insects were placed and mortality measured over time. A 100% mortality rate was archieved two days after treatment of adult E. vigintioctopunctata and S. litura larvae with some silica “AL06”-formulations. In contrast, mortality rate for E. vigintioctopunctata larva was only 30 to 70% after two days of treatment. Mortality rate was dose dependend, even though a linear correlation could not be found. Furthermore, the commercial substance “Advasan^®” was able to control the horticultural pest E. vigintioctopunctata within 48 hours successfully. For future horticultural applications, possible phytotoxic side effects of silica dusts and an application technology resulting in adequate leaf coverage have to be considered.     

胡杨内生真菌曲霉(Aspergillus sp.)链格孢(Alternaria sp.)的生理特性

采用接种法 ,对胡杨内生真菌曲霉 ( Aspergillus sp.)和链格孢 ( Alternaria sp.)在不同温度、p H、碳源、氮源、培养基及糖质量浓度下进行了生理实验研究。结果表明 :温度对两种菌株的生长和孢子产生具有明显的影响 ;曲霉 ( Aspergillus sp.) p H5～ 6时生长良好 ,而链格孢 ( Alternaria sp.) p H为 4～ 5时菌株生长良好 ,两种菌株均以蔗糖为主要碳源 ;菌丝干质量与培养基质量浓度呈正向关系。     

检疫杂草列当(Orobanche L.)

列当是一类寄生植物根部营寄生生活的列当科(Orobanchaceae)列当属(OrobancheL.)植物的总称,为我国进境植物检疫对象。最近,又被列为内检对象。列当属全世界有100多种,主要分布于地中海(埃及、叙利亚)、亚洲西部地区、东欧、俄罗斯的南部、中美洲南部及大洋洲、非洲东部和北部等地区,我国有23种,3变种,1变型,主要分布在西北地区,少数分布于北部和中部及西南的高海拔地区[1]。在我国引起严重危害的主要有埃及列当(瓜列当,O.aegyptiacaPers.)、分枝列当(大麻列当,O.ramosaL.)、向日葵列当(直立列当、二色列当,O.cumana Wallr)、列当(O.coe…     

胡杨内生真菌曲霉(Aspergillus sp.)链格孢(Altrnaria sp.)的生理特性

采用接种法,对胡杨内生真菌曲霉(Aspergillus sp.)和链格孢(Alternaria sp.)在不同温度、pH、碳源、氮源、培养基及糖质量浓度下进行了生理实验研究.结果表明温度对两种菌株的生长和孢子产生具有明显的影响;曲霉(Aspergillus sp.)pH 5～6时生长良好,而链格孢(Alternaria sp.)pH为4～5时菌株生长良好,两种菌株均以蔗糖为主要碳源;菌丝干质量与培养基质量浓度呈正向关系.     

Waarnemingen over het gedrag van zoösporen uit de zoösporangia vanOlpidium brassicae (wor.) dang

Summary The zoosporangial zoospores ofOlpidium brassicae are uniflagellate (fig. 1). Observations with a phase contrast microscope on living zoospores in watermounts showed that biflagellate zoospores resulted from zoospore fusion. Further, specimens were found with more than two flagella (fig. 2 and 3). As at zoospore discharge only uniflagellate zoospores occur, it may be, assumed that zoospores with more than two flagella are also the result of zoospore fusion. As there may be an analogy betweenO. brassicae andO. viciae,Kusano's explanation of the occurrence of compound zoospores with more than two flagella is discussed.     

番薯(甘薯)黑斑病[Ophiostoma fimbriatum(Ell.&Huls.) Nannf.]的防治研究

 番薯(甘薯)黑斑病在國內现已蔓延十几个省份,造成的损失十分驚人,估計每年在貯藏期要毁掉薯塊二十億斤以上,春薯地区,育苗期普遍發生爛床,例如在河北省疫区調查結果,以前未發現黑斑病时候,每味能采8次苗以上,现在由于黑斑病为害的結果,只能采1-3次苗,苗床即已坏掉。     

一株芹菜(Apium graveolens L.)软腐病菌Pectobacterium carotovorum subsp. odoriferum的特征

从北京通州地区芹菜软腐病样中分离获得的菌株QC01在实验室条件下能浸软芹菜叶柄组织,并能引起温室种植的芹菜软腐症状的产生。经病原菌表型特征分析,确定该菌株为有鞭毛的革兰氏阴性果胶杆菌Pectobacterium。QC01与参试的P.carotovorum subsp.odoriferum(Pco)菌株T5和CC1均具备在37℃以及在含有7%Na Cl培养基中生长的能力;能分解柠檬酸盐和液化明胶;除常见碳源外,QC01还能降解α-甲基葡糖苷、麦芽糖、山梨醇、阿拉伯糖和阿拉伯半乳聚糖。基于16S rRNA基因完整序列系统发育关系表明,QC01与其他Pco菌株聚集成明显的Pco类群。QC01和CC1 type II与已报道的Pco菌株JKI 582 type II和NB 1892的16S rRNA基因完整序列相似性为100%。这是首次在中国发现Pectobacterium carotovorum subsp.odoriferum引发芹菜软腐病。     

Morphological and molecular identification of Fusarium oxysporum f. sp. narcissi on poet’s daffodil (Narcissus poeticus L.) in Serbia

Journal of Plant Diseases and Protection - In autumn 2018, daffodil (narcissus) plants with basal bulb rot were noticed in a plantation in locality Jasika, Serbia. Morphological characterization...     

江苏省棉花枯萎病菌(Fusarium oxysporum f.vasinfectum (Atk.) Snyder et Hansen)专化类型的研究

根据江苏省不同枯萎病区病株的病症,不同菌系的培养性状,和对不同棉种的致病性状,可把江苏棉枯萎病菌分成南京型和启东型两个类型。前者只为害陆地棉,与美国的枯萎病菌相似。后者对陆地棉、海岛棉和中棉均能侵害,与南京型菌系有明显差别。因此认为启东型是枯萎病菌的一个新的类型。     

东北霜霉菌Peronospora manschurica(Naum.)Syd.对黄瓜霜霉病的诱导免疫作用

 本研究以多年筛选出的东北霜霉菌Peronospora manschurica(Naum.) Syd.为诱导菌,在黄瓜植株的3~4叶期,采用茎部注射、喷雾和灌根等三种诱导接种方法,诱导植株产生诱导抗性,测定东北霜霉菌对黄瓜霜霉病的免疫作用。研究结果表明:东北霜霉菌免疫作用的强弱与诱导接种方法有关。在3种诱导接种方法中,以注茎诱导接种法的免疫作用最强,使黄瓜植株产生的系统保护作用最明显,表现为黄瓜霜霉病的发病始期较对照株向后推迟12~13天,平均病情指数降低17.6;喷雾诱导接种的免疫作用较弱;而灌根诱导接种法,未能反应出东北霜霉菌的免疫作用。