松树抗松材线虫病机制研究进展

松材线虫病(Pine wilt disease)是由松材线虫Bursaphelenchus xylophilus引起的一种世界性森林病害。本文对松树感染松材线虫病后的组织病理学变化、生理生化响应、松树抗松材线虫分子生物学研究和抗病反应对松材线虫定殖影响等进行了总结和分析。     

日本松材线虫病研究的最新动向

该文重点对近2a日本松材线虫病的研究文献进行整理分析。目前松材线虫病的研究仍是日本国森林病虫害的主要研究课题。在松树的抗（感）病机理、线虫在树体内的活动与增殖规律、线虫与天牛的关系、生物防治以及新技术在研究中的应用等方面取得较大进展。     

松树松材线虫病抗性育种成果的早期利用

松树抗性育种,是通过一定的选择程序,确定和选拔出具有一定抗性的新品种。在对松材线虫病的抗性上,松树的不同品种、不同种源及单株个体之间,都可能存在差异。抗病品种选择,主要是在松材线虫病的发生区,在发病时间久、病情严重的林分中,所残存的极少数健康植株极有可能具有一定的抗病遗传性。2001年10月,我省实施在省内松材线虫病疫区的残存木上采种育苗,并连续两年在苗木上接种松材线虫,经过选择,初步确定接种线虫后能存活下来的苗木就具有一定的抗性。之后,又在省内其他地区及非疫区采种育苗,并接种松材线虫进行选择。对已选拔出的具有抗性的马尾松家系侯选木进行有效保存,并在现有的条件下加以利用。抗性育种工作流程一、接种材料来源从2001年开始,分别在省内10个县(市、区)的一些马尾松母树上采种,播种育苗后第二年对苗木第一次线虫接种,第三年对保存的苗木又进行第二次线虫接种。期间共选拔抗性苗木家系251个。线虫是从病害的高发区滁州市、和县和广德县等3市县的16棵被害木上采集,经实验室分离和增殖培养后分析,最后选择出致病力最强的线虫作为苗木接种的虫源。二、接种成活苗木的利用在马尾松实生苗木上接种松材线虫后进行人工筛选,第一次在每株苗木上接...     

松材线虫生防真菌伊氏线虫菌研究进展

松材线虫病对森林生态健康有显著影响,可以导致松林大面积死亡,有效预防松材线虫病是维护森林生态系统的重要措施。伊氏线虫菌是一种松材线虫的内寄生真菌,具有作为松材线虫病生物防治的天敌的潜力。近几年,对于这种鲜为人知的真菌的研究增多。本文从该菌的发现、形态学、培养、侵染机制、分子层面研究和生物防治应用等方面较系统全面地介绍该菌。伊氏线虫菌共有6个菌株,能产生月形孢子和杆状孢子2种类型的孢子,月形孢子能黏附到松材线虫体表并寄生于体内将其杀死。伊氏线虫菌能在松树和松树分泌的树脂中存活,通过产生宿主松树的香味而引诱松材线虫。培养条件对伊氏线虫菌生长、产孢、孢子侵染活力的影响较大,可以在培养基中添加甘氨酸等增强其对环境的抗性。伊氏线虫菌基因组已被完整测序,还克隆出1个对松材线虫具有强毒力的丝氨酸蛋白酶基因,同时在菌株细胞内发现内生细菌的存在,可以通过分子方法检测该菌。在温室和野外采用树干注射、树冠喷洒和伤口接种等不同方法施用含有该真菌的生防菌,均显示其能降低松材线虫对松树的侵染。目前对于该菌的研究主要集中在实验室,对于林间防治应用也有研究,但还是较少。关于该菌未来的研究可以从几方面开展:1)分子层面弄清其侵染机制;2)商品化生物制剂; 3)野外防治方案; 4)松褐天牛与伊氏线虫菌之间的关系。     

松汁中检出的捕食线虫的真菌

<正> Ⅰ.序言日本对松树枯萎病有一些防治方法。该病系松材线虫Bursaphelenchus Lignicolus及日本松天牛Monochamus alternatus所致。据信,利用天敌消灭松材线虫,防止松树枯萎病的发生是个可行的方法。当在研究线虫对松汁是否显趋化性时,偶然发现了捕食线虫的真菌。该真菌Arthrodotrys sp.在琼脂培养基上对松材线虫有捕食性,是线虫天敌的候选者。这与Mamiya和Tamura二人在日本松天牛蛹室中发现的Dactylella Ieptospora相似。     

日本松材线虫防治措施

从20世纪初期开始，日本松林就不断受到松材线虫的危害。1970—1972年发现病原体松材线虫及其媒介松墨天牛后，便开始防治松材线虫的重点研究，并发现了导致松树枯死的强有力的传染病实体。1977年制定《松材线虫特别防除措施法》，采取了紧急防治对策。20多年来日本在防治松材线虫领域积累了一些经验和成果，1997年日本全国森林病虫兽害防除协会编辑出版了《松材线虫》一书，这些研究成果可供我国防治松材线虫借鉴。     

松材线虫在我国的分布

松材线虫[Bursaphelenchus xylophilus(Steiner＆Buhrer,1934)Nickle,1970]引起的松树萎蔫病(Pine Wilt Disease)是一种毁灭性病害。松树感染此线虫后可很快死亡。作者在温室用松材线虫接种三年生黑松苗,35d后76％的松苗即枯死了。据记载,在日本由于松材线虫为害引起的木材年损失量最高可达240万m~3 。自1981年以来,在我国湖南、贵州、云南、浙江、江苏等省都有松树枯死现象。1982年首次在南京发现松材线虫危害。以后,病情逐年加剧,到1987年已累计病死松树60万株,成为我国突出的、至今尚无防治良策的一大森林病害。     

从适生性分析松材线虫对云南松树树种的威胁

松材线虫病是松树的一种毁灭性病害。本文从松材线虫的为害状况,病原线虫的形态特征,云南松树树种的感病性以及环境等因素分析得到,此病对云南的松树树种特别是云南松具有潜在的威胁,进而提出了5条预防措施。     

拟松材线虫与松树萎蔫病

一、问题的提出 日本在松树萎蔫病的调查过程中,Mami-ya和Ende于枯死松树中发现一种与松材线虫Bursaphelenchus xylophilus(Steiner etBuhrer)Nickle极相似的线虫,它的雌虫和幼虫的尾部有一明显的指形突与B.xylophilus不能交配,被定为新种—Bursaphelenchusmucronatus(Mamiya et Ende),即拟松材线虫。据日本报道,拟松材线虫分布范围比     

松材线虫鉴定技术初探

松材线虫病,又称松树枯萎病,是由松材线虫感染松树并导致该树在极短时间内迅速死亡的一种森林生物灾害。此病主要危害松属植物,在河南省主要危害油松、华山松、白皮松、雪松和日本落叶松。松树一旦感病即很难治愈,最快的仅在40多天内即可枯死,因此又被称为松树的“癌症”。目前,世界上已有40多个国家和多个组织都将其列为检疫对象。对松材线虫的鉴定目前除了对感病松树进行外观和生物学判断以外,主要采用对疑似感病松树进行取样,然后对线虫进行分离,在显微镜下进行鉴定的方法进行。     

开展松材线虫病抗性选育 保护我国松林资源

松材线虫病是我国松林毁灭性病害,已造成数千万松株死亡,发生区经济损失巨大,目前此病害正威胁着南方重点林区及重要风景名胜区松林的安全。我国松属资源丰富,科技人员队伍组织体系完备,抗性选育研究已有较好基础。因此尽快开展抗性选育有利于发生区森林恢复、非发生区林分改造和结构调整,有利于保护我国森林资源。本文对开展抗性选育提出了具体建议。     

Comparison of histological responses and tissue damage expansion between resistant and susceptible Pinus thunbergii infected with pine wood nematode Bursaphelenchus xylophilus

Pine wilt disease caused by the pine wood nematode (PWN), Bursaphelenchus xylophilus, has been epidemic and has had disastrous impacts on pine forests and forest ecosystems in eastern Asia. Many pine species in this area are susceptible to this disease. Pinus thunbergii is particularly susceptible. In Japan, tree breeders have selected surviving trees from severely damaged forests as resistant candidates, and have finally established several resistant varieties of P. thunbergii. However, this breeding procedure requires much time and effort due to the lack of physiological and phenotypical information about resistance. To investigate the resistance mechanisms of selected P. thunbergii, we compared histochemical responses, tissue damage expansion, and PWN distribution in resistant and susceptible clones of P. thunbergii after PWN inoculation. The results suggested that the mechanisms of resistance are as follows: damage expansion in the cortex, cambium, and xylem axial resin canals are retarded in resistant trees soon after inoculation, probably due to the induction of wall protein-based defenses. Suppression of PWN reproduction was particularly caused by inhibition of damage expansion in the cambium. The slow expansion of damage in each tissue provides time for the host to complete the biosynthesis of lignin in the walls of cells that surround the damaged regions. This lignification of cell walls is assumed to effectively inhibit the migration and reproduction of the PWNs. The mechanism of initial damage retardation is presumed to be a key for resistance.     

松材线虫病的潜伏侵染及松墨天牛传播新途径

在南京用松材线虫接种 7种松树 ,于第 2a在无任何症状的松树的接种点上方 10cm处取样 ,分离线虫。结果表明松材线虫病的潜伏侵染现象比较普遍。在不同的松树品种上潜伏侵染现象有所差异。感病黑松和赤松很快死亡 ,只有在接种量小的情况下才有潜伏侵染现象发生。抗病性强的火炬松和湿地松感病后潜伏侵染现象比较普遍 ,并且样品中的线虫量也较高。而抗病性中等的马尾松和刚松感病后潜伏侵染现象的普遍性及样品中的线虫量均处于中等。短针松接种松材线虫后既不枯死 ,也无潜伏侵染现象。松墨天牛传播松材线虫的试验结果表明 ,未携带松材线虫的松墨天牛成虫在松材线虫病松枝上取食后 ,再到健康松枝上取食 ,有传播松材线虫的可能。这些结果表明在松材线虫病新病区清理病死木时 ,应采取早期诊断技术 ,把未表现症状的松树一起清除 ,以达到防治目的。     

Comparison of the gene expression profiles of resistant and non‐resistant Japanese black pine inoculated with pine wood nematode using a modified LongSAGE technique

The Japanese black pine (Pinus thunbergii) is highly susceptible to pine wilt disease caused by the pine wood nematode (PWN; Bursaphelenchus xylophilus). To cope with this disease, researchers and tree breeders selected PWN‐resistant individuals in a previous breeding program. In an attempt to understand the mechanisms of resistance in the Japanese black pine, we created four LongSAGE (serial analysis of gene expression) libraries. A total of 20 818 tags were studied, including 5194 tags from a PWN inoculated resistant pine, 5218 a non‐inoculated resistant pine, 5194 an inoculated non‐resistant pine, and 5212 a non‐inoculated non‐resistant pine. The analysis of the libraries indicated that 14 tag species were significantly up‐regulated (e.g., pathogenesis‐related proteins 2 and 4, osmotin, lipoxygenase, and chalcone synthase), and nine were down‐regulated (eukaryotic translation initiation factor SUI1, translationally controlled tumor protein, and xyloglucan endotransglycosylase) by the PWN inoculation in both the resistant and non‐resistant pines. On the other hand, 38 tag species were significantly expressed at a higher level only in the resistant pine (catalase, dienelactone hydrolase family protein) and 25 were expressed at a higher level in the non‐resistant pine (pathogenesis‐related proteins 1, 2, and 3, and leucoanthocyanidin dioxygenase). These differentially expressed genes are presumed to reflect some of the differences between the resistant and non‐resistant pines. Our results provide valuable information on the complex responses induced in the resistant and non‐resistant pine trees in response to PWN invasion.     

日本松材线虫病治理技术考察

日本是世界上松材线虫发生最早、受害损失最严重的国家，也是对松材线虫研究最深入、控制经验最丰富、治理技术最先进的国家。通过对该国多个林木育种中心、森林综合研究所及基层森林经营管理机构、生产者等的访问交流和实地考察，较系统地介绍了松材线虫病在日本的发生危害、研究现状和实用控制技术，提出了有效预防、治理松材线虫病的措施和方法。     

抗松材线虫病马尾松种源化学成分与抗性机理研究（第Ⅲ报）——接种松材线虫引起抗性马尾松种源中性萜类含量变化关系的研究

通过气相色谱分析研究了高抗、中抗和敏感马尾松种源在接种松材线虫（PWN）后所引起的中性萜类（主要是倍半萜类）组分含量变化规律以及含量变化与种源抗性间相关性变化规律。结果表明，接种PWN使抗性马尾松种源中某些萜类组分如长叶烯等增多，而某些组分如反式石竹烯等减少；接种PWN使高抗种源中长叶烯与反式石竹烯含量比值先减小后增大，且超过接种前的水平，但是未改变种源的抗病特征；树木生长过程对种源抗性及本研究没有造成影响和干扰。     

Suggestions on management measures of pine forest ecosystems invaded by <Emphasis Type="Italic">Bursaphelenchus xylophilus</Emphasis>

Pine wood nematode （PWN）, Bursaphelenchus xylophilus （Steiner et Buhrer） Nickle is an important invasive alien species in forests of China and has become one of the most destructive forest diseases. In order to improve the resistance and resilience of pine forest ecosystems against B. xylophilus invasion and make the pine forest ecosystem more timely responsive to PWN invasion, we made some recommendations based on five years of intensive observations. We advocate a set of management measures with the theme “Prevention is priority, but integrated with curative techniques and ecological resilience” on the pine forest ecosystem invaded by B. xylophilus; details of accurate measures are proposed. The aim is to discover the underlying problems of present pine forest ecosys-tems and to take, correspondingly, administrative measures and strategies, which will encourage the pine forest ecosystem to develop in a benign way.     

马尾松不同种源氨基酸含量与抗松材线虫病的关系

在选出和验证抗病马尾松种源的基础上,研究了马尾松不同抗病性种源的树体内氨基酸含量的差异。结果表明,抗病种源在接种松材线虫前后均比较感种源含有较少的组氨酸、苏氨酸、甘氨酸、异亮氨酸、胱氨酸、甲硫氨酸、亮氨酸、酪氨酸和精氨酸等９种游离氨基酸。它们与感病指数均呈正相关,这说明游离氨基酸含量低的马尾松种源抗松材线虫病。１１种固态氨基酸的含量与感病指数有负相关性,说明其含量较高的种源具较强抗病性能。     

Effects of Pulsed Magnetic Field on Biochemical and Physiological Characters and Ultrastructure of Pine Wood Nematode

In this paper,we employed the pulsed magnetic field(PMF) processing to investigate the effect of different pulse rise time and treatment time on the survival,reproduction,cellulase activity and surface characteristics of the pine wood nematode (PWN).The results showed that the wider pulse and the longer treatment time were able to reduce the survival,and inhibit the cellulase activity and reproduction of PWN.The 4th instar and females had a strong resistance to the pulsed magnetic field. With pulse rise time of 10 ms and the treatment of 60 min,the adjusted mortality of PWN was 100%. After the PMF treatment,the cellulase activity of PWN increased within a short time,and then declined with the treatment time.The observation with a scanning electron micrograph(SEM) revealed that there was no significant change in morphology of PWN,but the quantity of rod-shaped bacteria carried by PWN was reduced.