北京地区苹果及葡萄根限捕食线虫具菌的种类及分布

对北京郊区果园的苹果和葡萄根际的捕食线虫真菌进行调查,发现苹果和葡萄的根际不同位置的捕食线虫真菌数量不同,内标际捕食线虫真菌数量大于外根际,而外根际捕食线虫真菌数量又叁于游离土壤中的捕食线虫真菌数量;在苹果根际发现的捕食线虫真菌共有９种：Ａｒｈｒｏｂｏｔｒｙｓｄａｃｔｙｌｏｉｄｅｓ,Ａ．ｃｌｉｇｏｓｐｏｒａ,Ａ．ｍｕｓｉｆｏｒｍｉｓ,Ａ．ｃｌａｄｏｄｅｓ,Ａ．ｂｒｏｃｈｏｐａｇａ,Ａｒｔｈｒｏｔｒ     

果树根围的植物线虫种群结构调查

对莆田市九华农场同一地段的龙眼、橄榄、楷杷、葡萄等四种果树根部的植物线虫种类和群体结构进行调查,结果表明：果树类别对植物线虫种类、群体组成有一定影响。从以上四种果树的根部和根际土壤中共鉴定出Ａｐｈｅｌｅｎｃｈｏｉｄｅｓ、Ａｐｈｅｌｅｎｃｈｕｓ、Ｃｒｉｃｏｎｅｍｏｉｄｅｓ、Ｈｅｌｉｃｏｔｙｌｅｎｃｈｕｓ、Ｈｅｍｉｃｒｉｃｏｎｅｍｏｉｄｅｓ、Ｐａｒａｔｙｌｅｎｃｈｕｓ、Ｐｒａｔｙｌｅｎｃｈｕｓ、Ｒｏｔ     

坡向尺度差异对大理苍山捕食线虫真菌分布格局的影响

为了解大理苍山地区不同尺度坡向上捕食线虫真菌的分布格局及其驱动因素,利用系统采样法对大理苍山东、西坡及其次级南、北坡的捕食线虫真菌进行调查。按照五点采样法采集苍山东、西坡及其次级南、北坡土壤样品共300份。采用传统方法对捕食线虫真菌进行分离纯化,结合形态特征和分子生物学方法鉴定所得菌株,按照新分类系统进行分类,鉴定为3属12种57株捕食线虫真菌。结果表明：苍山各尺度坡向捕食线虫真菌检出率和多样性指数均是西坡大于东坡,次级南坡大于次级北坡。次级南、北坡向间捕食线虫真菌群落差异大于东、西坡向间;西坡次级南、北坡向间的群落差异最大;东、西坡向的次级南坡向间群落差异也较大;东坡次级北坡与西坡次级北坡间的群落最为相似。产黏性菌网的Arthrobotrys属、产黏性球和黏性分枝的Dactylellina属在东、西坡及其次级南、北坡间均有分布,而产收缩环的Drechslerella属仅在西坡有分布。因此,坡向是影响苍山捕食线虫真菌空间分布格局的驱动因子之一,不同尺度坡向上捕食线虫真菌分布格局存在差异;次级南、北坡间捕食线虫真菌群落差异性比东、西坡间大,小尺度坡向间地理屏障对捕食线虫真菌分布格局的影响大于大尺度坡向间环境异质性的作用;环境筛选和扩散限制均会影响到捕食线虫真菌的群落构建过程。     

葡萄根际线虫种群的研究

对２４个栽培葡萄品种及１２个中国野生葡萄株系的根际线虫种群研究结果表明：寄生类线虫占线虫总量的１０．５％,腐生类占８８．４％,捕食类占０．３％,矛线类占０．８％。寄生线虫共鉴定出１０个属。其中螺旋线虫属的数量及分布寄主最多,短体线虫次之。不同种和品种的根际寄生线虫种类及虫口密度差异较大。大多数栽培品种根际的寄生线虫种类及数量明显高于野生种,野生种受线虫危害较轻。     

指隔孢属新种——粗壮指隔孢*

报道了一指隔孢属（Ｄａｃｔｙｌｅｌｌａ）新种：粗壮指隔孢（ＤａｃｔｙｌｅｌｌａｃｒａｓｓａＺ．Ｑ．Ｍｉａｏ,Ｌ．Ｐ．Ｌｅｉ&X．Ｚ．Ｌｉｕ）。该新种是在进行云南食线虫真菌调查时发现的,它能产生典型的大小两种分生孢子,将大小分生孢子分别挑单孢培养,仍能同时产生大小两种分生孢子;分生孢子梗粗壮,全壁芽殖式产孢和分枝;捕食器官为螺旋状菌丝分枝组成的三维网。研究标本保存于中国科学院微生物研究所真菌标本室（ＨＭＡＳ）。     

果树根围的植物线虫种群结构调查

对莆田市九华农场同一地段的龙眼、橄榄、枇杷、葡萄等四种果树根部的植物线虫种类和群体结构进行调查,结果表明：果树类别对植物线虫种类、群体组成有一定影响。从以上四种果树的根部和根际土壤中共鉴定出Ａｐｈｅｌｅｌｅｎｃｈｏｉｄｅｓ、Ａｐｈｅｌｅｎｃｈｕｓ、Ｃｒｉｃｏｎｅｍｏｉｄｅｓ、Ｈｅｌｉｃｏｔｙｌｅｎｃｈｕｓ、Ｈｅｍｉ－ｃｒｉｃｏｎｅｍｏｉｄｅｓ、Ｐａｒａｔｙｌｅｎｃｈｕｓ、Ｐｒａｔｙｌｅｎｃｈｕｓ、Ｒｏｔｙｌｅｎｃｈｕｓ、Ｔｙｌｅｎｃｈｕｓ、Ｔｒｉｃｈｏｄｏｒｕｓ等１０个属的植物线虫。龙眼上植物线虫有６属,其群体由２～４个属组成,优势线虫属Ｔｒｉｃｈｏｄｏｒｕｓ;橄榄上植物线虫有７属,其群体由１～７个属组成,优势线虫属为Ｐａｒａｔｙｌｅｎｃｈｕｓ;枇杷上植物线虫有６属,其群体由２～５个属组成,优质线虫属为Ｐａｒａｔｙｌｅｎｃｈｕｓ;葡萄上植物线虫有５属,其群体由２～５个属组成,Ｈｅｌｉｃｏｔｙｌｅｎｃｈｕｓ的分布频率较高,而Ｐｒａｔｙｌｅｎｃｈｕｓ的虫口密度最大。     

中国盐碱土壤中AM菌的生态分布

对我国盐碱土壤中丛枝菌根（Ａｒｂｕｓｃｕｌａｒ Ｍｙｃｏｒｒｈｉｚａ,ＡＭ） 菌的种属构成、生态分布状况进行了研究．结果表明,不同地区ＡＭ 菌种属构成不同,其种属组成、分布与土壤类型、碱化度和土壤有机质含量有关．盐渍化砂土、壤土和粘土中,Ｇｌｏｍｕｓ 属的真菌数量最多,Ａｃａｕｌｏｓｐｏｒａ 属次之,而Ｇｌｏｍｕｓ 属中的Ｇ．ｍｏｓｓｅａｅ 则是分布最为广泛的菌种．随土壤碱化度的增加,Ｇｌｏｍｕｓ ｍｏｓｓｅａｅ 出现频率随之相对增加．在一定范围内有机质含量越高,土壤中ＡＭ 菌种和属的种类就越多．ＡＭ 菌的种属组成因不同寄主植物而异,其中豆科植物根围中ＡＭ 菌分布的种属数量最多．     

指隔孢属新种——粗壮指隔孢

报道了一指隔孢属（Ｄａｃｔｙｌｅｌｌａ）新种：粗壮指隔孢（Ｄａｃｔｙｌｅｌｌａ ｃｒａｓｓａ Ｚ．Ｑ．Ｍｉａｏ,Ｌ．Ｐ．Ｌｅｉ＆Ｘ．Ｚ．Ｌｉｕ）。该种种是在进行云南食线虫真菌调查时发现的,它能产生黄型的大小两种分生孢子,将在发生孢子分别挑单孢培养,仍能同时产生大两种分生孢子,分包子梗粗装,全壁芽殖式产孢和分枝;捕食器官为状菌丝分枝组成的三维网。研究标本保存于中国科学院微生物研究所真菌标本室（ＨＭＡ     

丛枝菌根真菌对玉米和棉花内源激素的影响

在温室盆栽条件下研究了丛枝菌根（Ａｒｂｕｓｃｕｌａｒ ｍｙｃｏｒｒｈｉｚａｓ,ＡＭ）真菌：Ｇｉｇａｓｐｏｒａ ｒｏｓｅａ Ｎｉｃｏｌ．＆ Ｓｃｈｅｎｃｋ、Ｇｌｏｍｕｓ ｍｏｓｓｅａｅ（Ｎｉｃｏｌ．＆ Ｇｅｒｄ．）Ｇｅｒｄｅｍａｎｎ ＆ Ｔｒａｐｐｅ和Ｇｌｏｍｕｓ ｖｅｒｓｉｆｏｒｍｅ （Ｋａｒｓｔｅｎ）Ｂｅｒｃｈ对玉米和棉花植株内源激素的影响。结果表明,ＡＭ真菌在正常供水和干旱条件下均能显著提高     

中国的捕食线虫真菌：V.节丛孢属

本文报道了分离自我国部分省区的捕食根结线虫、蘑菇堆肥线虫、小杆线虫和秀丽隐杆线虫的节丛孢属菌１８个种,其中２个新种,７个我国新记录种。新种中贵洲节从孢Ａｒｔｈｒｏｂｏｔｒｙｓ ｇｕｉｚｈｏｕｅｎｓｉｓＫ．Ｑ．Ｚｈａｎｇ ｓｐ．ｎｏｖ。和秀丽节丛孢Ａ．ｖｅｎｕｓｔａＫ．Ｑ．Ｚｈａｎｇ ｓｐ．ｎｏｖ。此外,文中还列出了节丝孢属１８个种的检索表。     

捕食线虫真菌在北京地区果园中的季节性分布

通过对北京海淀区2个苹果园和2个葡萄园根际捕食线虫真菌2年的季节性变化调查,共分离到199个捕食线虫真菌菌株,隶属3个属16个种,Arthrobotrysdactyloides分离频率最高,其次是A.oligospora,A.conoides和Stylopagesp.。捕食线虫真菌的数量在晚春夏初最丰富,秋季次之,冬夏最少。通过统计分析,捕食线虫真菌数量的季节性变化与温度线性相关,而与线虫总数S形相关,与土壤湿度和植物寄生线虫数量无显著相关。     

不同基质对指状节丛孢孢子捕食器官形态建成的影响*

利用牛粪、土壤等基质诱导捕食线虫真菌指状节丛孢产生孢子捕食器官。孢子捕食器官形成过程与正常情况下捕食器官的形成基本相似;不同基质诱导孢子捕食器官的能力不同, 同种内不同菌株间形成孢子捕食器官的能力也有异别。预培养实验,温度处理实验的结果表明基质中诱导孢子捕食器官的主要诱导因子可能是某些化合物,这些物质在100℃下基本上丧失诱导活性;在诱导孢子捕食器官的过程中,基质中的微生物所起的作用不大。     

中国的捕食线虫真菌——Ⅴ.节丛孢属

本文报道了分离自我国部分省区的捕食根结线虫(Meloidogyne spp.)、蘑菇堆肥线虫(Aphelenchoides composticla)、小杆线虫(Rhabditis sp.)和秀丽隐杆线虫(Caenorhabditis elegans)的节丛孢属菌18个种,其中2个新种,7个我国新记录种。新种是贵州节丛孢Arthrobotrys guizhouensis K.Q.Zhang sp.nov.和秀丽节丛孢A.venusta K.Q.Zhang sp.DOV.。此外,文中还列出了节丛孢属18个种的检索表。     

捕食线虫丝孢菌的菌寄生性测定

研究了节丛孢Arthrobotrys、单顶孢Monacrosporium和隔指孢Dactylella三个捕食线虫丝孢菌属16个菌株,对水稻立枯丝核菌RhizoctoniasolaniAG1、大豆核盘菌Sclerotiniasclerotiorum、茄科镰刀菌Fusariumsolani和恶疫霉Phytophthoracactorum四种常见土壤植物病原真菌的菌寄生性。结果表明供试菌可以通过弹簧式菌丝圈缠绕、类附着胞结构吸附、简单的菌丝缠绕或者贴附寄主菌丝生长四种方式寄生病原菌。其中,绝大多数菌株对立枯丝核病菌有寄生作用,一些供试真菌对其它三种病原真菌有寄生现象。利用孢子液浸泡法测定了其中5种捕食线虫真菌对核盘菌菌核的寄生能力,显示有较高寄生率。     

Nematode-Capturing Hyphomycetes from Soils over Xerophytic Calcareous Rock in Upper Bavaria*

Nematode-capturing hyphomycetes were isolated from soil and plant debris on the south slope of a hill in the Jurassic of Upper Bavaria. The following species were found: Arthrobotrys arthrobotryoides, A. dactyloides, A. oligospora, A. superba, Dactylella astenopaga, Monacrosporium cionopagum, M. psychrophilum. Endozoic fungal parasites of nematodes were not isolated. With one fungal propagule of nematode-destroying fungi in 1.7 g soil, the density is only slightly lower than values given for agricultural soils.     

Rhizosphere Colonization and Control of Meloidogyne spp. by Nematode-trapping Fungi

The ability of nematode-trapping fungi to colonize the rhizosphere of crop plants has been suggested to be an important factor in biological control of root-infecting nematodes. In this study, rhizosphere colonization was evaluated for 38 isolates of nematode-trapping fungi representing 11 species. In an initial screen, Arthrobotrys dactyloides, A. superba, and Monacrosporium ellipsosporum were most frequently detected in the tomato rhizosphere. In subsequent pot experiments these fungi and the non-root colonizing M. geophyropagum were introduced to soil in a sodium alginate matrix, and further tested both for establishment in the tomato rhizosphere and suppression of root-knot nematodes. The knob-forming M. ellipsosporum showed a high capacity to colonize the rhizosphere both in the initial screen and the pot experiments, with more than twice as many fungal propagules in the rhizosphere as in the root-free soil. However, neither this fungus nor the other nematode-trapping fungi tested reduced nematode damage to tomato plants.     

Binding characteristics of lectins involved in the trapping of nematodes by fungi

Seventeen saccharides were tested for their ability to bind to the trap lectins of three species of nematode-trapping fungi and prevent nematode capture. The lectin of Arthrobotrys conoides was found to be inhibited by alpha-d-glucose/d-mannose and similar saccharides. The lectins of Monacrosporium eudermatum and Monacrosporium rutgeriensis were inhibited by alpha-l-fucose and 2-deoxy-d-glucose, respectively. Human group O(H) erythrocytes agglutinated to traps of M. eudermatum but not A. conoides or M. rutgeriensis. There was no agglutination of group A or B to traps formed by all three fungi. Exposure of the traps to trypsin eliminated the ability to capture nematodes. The presence of d-glucose/d-mannose and l-fucose residues on the nematode cuticle was suggested through the use of commercially prepared lectin-peroxidase conjugates.     

根结线虫天敌真菌及其高效菌株筛选

本文报道捕食和寄生南方根结线虫(Meloidogyne incognita)和爪哇根结线虫(M.javanica)的天敌真菌6属14种。其中Arthrobotrys candida A.cladodes var.macroides,A.musiformis,Monacrosporium cionopagum,M.doedycoides,Drechmeria coniospora,Harposporium crassum,H.lilliputanum,Myzocytium humicola和Verticillum coccospora为我国新纪录种。室内测定结果表明:GACA 1B(Arthrobotrys oligospora)、GACM 102(Monacrosporium doedycoides)菌株对南方根结线虫和爪哇根结线虫均具极高的捕食率,接种线虫7天后,捕食率达98%以上,接种20天后,捕食率均达100%。     

The influence of saprophytic competition on nematode predation by nematode-trapping fungi

Competivive stress imposed by common soil saprophytes may cause an increase in predation by the nematode-trapping fungi, Arthrobotrys oligospora and Monacrosporium cionopagum, on the bacteria-feeding nematode Acrobeloides buetschli. Nematode-trapping species grown with saprophytic competitors in an artificial soil substrate increased their trapping activity compared to control cultures. The results support the hypothesis that competition stimulates the predatory activity of nematode-trapping fungi as an adaptation to overcome their low competitive saprophytic ability.     

Ultrastructure of Nematode-Trapping Fungi

Capture cells differ ultrastructurally from vegetative cells in the nematode-trapping fungi, Dactylella drechslerii, Monacrosporium rutgeriensis and Arthrobotrys dactyloides, which capture prey by means of adhesive knobs, adhesive hyphal networks, and constricting rings, respectively. Adhesive knobs and adhesive networks contain dense inclusions not found in hyphal tips or subapical regions of the vegetative hyphae, and rough- and smooth-surfaced membranes are abundant in these trap cells. The fine structure of constricting rings differs from that of adhesive traps, and it is altered by closure. In the open configuration, there are membrane-bound inclusions, labyrinthine networks, and electron-lucent regions between the protoplasts and cell wall, all localized on the luminal side of the ring cells. After closure, these features no longer are evident and the cytoplasm of trap cells stains less densely.