松材线虫和拟松材线虫不同株系致病性的研究*

１９９０－１９９３年，从国内外收集的松材线虫９个株系和拟松材线虫５个株系，用皮接法接种３－６年生的松苗，测定线虫的致病性。结果表明，松材线虫的致病力明显高于拟松材线虫，其中国内的５个株系致病力最高，拟松林线虫通常不致病或致病力极低，在同一线虫种内，株系间致病力随寄主不同而不同。在寄主死亡速度上，寄主相同并死亡率相同或相近时，采自南京、广东马尾松病树上的线虫株系接种后，寄主平均死亡时间略短于其它株系     

“松材线虫SCAR标记与系列分子检测技术及试剂盒研制”项目通过鉴定

2006年5月，由南京林业大学森林资源与环境学院叶建仁教授主持完成的“松材线虫SCAR标记与系列分子检测技术及试剂盒研制”通过了江苏省科技厅组织的科技成果鉴定。该项研究对松材线虫与拟松材线虫特异片段进行了系统筛选，共获得了7个松材线虫DNA特异片段与5个拟松材线虫DNA特异片段，为松材线虫与拟松材线虫的分子鉴定奠定了基础。首次将2个松材线虫与2个拟松材线虫的DNA特异片段成功转化为SCAR标记，丰富了松材线虫与拟松材线虫分子标记方法。首次采用SCAR标记方法成功构建了松材线虫检测试剂盒，PCR检测过程仅需2．2小时。首次成功标记了一个可用于检测松材线虫的非放射性探针DIG-F2／R1。用该探针对线虫基因组DNA点杂交，松材线虫均表现有较强的杂交信号，而拟松材线虫、霍夫曼尼伞滑刃线虫、大核滑刃线虫、长尾属线虫等均无杂交信号。     

松材线虫体外酶组成分析

将表面消毒的松材线虫，在Ｔｒｉｓ－ＨＣｌ缓冲液中振荡培养，培养液经硫酸铵沉淀、透析、冷冻真空干燥，制成的干样，用于聚丙烯酰胺凝胶电泳。结果表明，松材线虫能向体外分泌多种可溶性蛋白，对其中酶组成分析发现有纤维素酶、过氧化物酶、蛋白酶、淀粉酶等。同样条件下未能检出β－半乳糖酶、β－木糖酶、β－葡聚糖酶、漆酶等。     

松材线虫病树早期诊断的研究：Ⅱ松树品种,接种量及线虫来源对 …

１９９７－１９９８年用不同量的松材线虫接种黑松和马尾权,用３个来源的松材线虫接种马尾松,用松材线虫接种７种松种,接种后对松树的流胶情况定期进行观察。     

松材线虫和拟松材线虫雄虫交合伞形状的比较

松材线虫和拟松材线虫雄虫交合伞形状的比较刘伟，杨宝君关键词松材线虫，拟松材线虫，雄虫交合伞松材线虫病是松树的一种毁灭性病害。病原松材线虫ＢｕｒｓａｐｈｅｌｅｎｃｈｕｓｘｙｌｏｐｈｉｌｕｓＮｉｃｋｌｅ（简作Ｂｘ）的形态与非病原拟松材线虫Ｂ．ｍｕｃｒｏｎ...     

自然侵染的松材线虫在松树体内的分布与消长

在松材线虫病为害季节，通过在发病区的不同小班选择刚出现枯萎症状的松树作为标准株，每隔一定时间，在不同部位取样、分离并计算松材线虫含量，结果表明受松材线虫侵染的松树、自出现初始症状的1个月左右时间，树冠枝条松材线虫含量显著多于其它部位，以后松材线虫在松树体内的分布趋于均匀。     

拟松材线虫研究进展

松材线虫和拟松材线虫共同构成松材线虫复合群体,为松材线虫病的病原物。拟松材线虫危害过去没有引起足够重视,相关研究工作不如松材线虫细致。近年来,随着拟松材线虫致病性增强现象不断被报道,人们逐步加强了拟松材线虫研究。本文从拟松材线虫分类学特征、致病性研究及与松材线虫关系等角度对拟松材线虫研究进展进行综述,并展望未来可能的研究热点。     

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。     

松材线虫病死木处理试验

为探索松材线虫病死木的利用问题，作者从1988年起，先后在松材线虫病发生地6家木制品厂进行了病死木处理试验，其工艺流程是病死木制材后加温烘干，温度65－120℃，杀灭了松材线虫和松褐天牛，进而在木板上涂胶、高温高压下（140－150℃，7－10kg/cm^2)压成不同规格的层压胶合板。工艺是安全可行的。松材线虫病死木处理试验结果表明，这是控制松材线虫病扩散蔓延的有效途径之一。     

苦豆碱对松材线虫的杀线活性

研究了苦豆草中苦豆碱对松材线虫的杀线活性，讨论了苦豆草生物碱在研究防治松材线虫病中的意义。使用含苦豆碱的培养基培养灰葡萄抱菌菌丝的生物测定方法，测定了苦豆碱对松材线虫的杀线活性，５天后培养基中苦豆碱的ＬＣ５０＝２．６３×１０－５ｇ／ｍｌ，当浓度为１×１０－４ｇ／ｍｌ和２．６３×１０－５ｇ／ｍｌ时，１５天后苦豆碱的杀线率分别为９９．９％和９４．３％。     

THE DEVELOPMENT PATTERN OF DOTHISTROMA NEEDLE BLIGHT AND ITS CONTROL

From field investigations and inoculations,Dothistroma pini,the pathogen ofDothistroma needle blight was found to overwinter as mycelium and unmatured acervuli in infectedneedles.The conidia were spreaded mainly by rain splash.The disease became widespread by trans-porting discased seedlings and seions conidia spread throughout the growing season,but mainlyfrom May to July.The diseade was found in both stand locations in each summer of investigation.The outbreak severity was serious in pure stands of susceptible pine and mixed stands with largecomponents of suseeotuble pine.but slight in mixed stands of unsusceptible species with small com-ponents of suseeptible hosts.The disease was less severe in pruned stands than in unpruned stands.The disease was most serious near the infection centre.indoor and outdoor tests,it was shown thatChlorothalonil smoke,Chlorothalonil spray and Thiram and Asomate sprays were effective controlfungicides.     

Localized within‐ and between‐tree variation in nematode distribution during latent state of pine wilt disease makes the disease status cryptic

The pinewood nematode (PWN), Bursaphelenchus xylophilus, is the causal agent of pine wilt disease, an epidemic disease that has severely damaged pine forests in East Asia. The disease has spread to northern areas in Asia and parts of Europe. To prevent disease spread as the forefront of damage prevention, a better understanding of infection status is highly important. Not all infected trees show disease symptoms, and such asymptomatic PWN‐carrying trees are likely to be overlooked and can become a pathogen reservoir. To elucidate PWN infection status in asymptomatic trees, we performed PWN inspection of branches and trunks in 21 test trees in two different conditions: trees that had experienced PWN inoculation and those with suspected PWN infection that had experienced transient foliage discoloration. We detected PWNs in eight test trees (38%) and in 13 (1.5%) of a total of 843 samples. The difference in these percentages suggests that nematode inhabitation was highly localized within the trees, possibly owing to the restricted migration of PWNs. Our data demonstrated that trees that were once weakened but recovered their vigour can persist, as the asymptomatic carriers, in the forest. The implications for disease control are also discussed.     

福建省松材线虫病预防措施及可持续控制对策

松材线虫病是松树的特大毁灭性病害，其病原是松材线虫，传播途径主要是靠松墨天牛携带。福建省已处在松材线虫病的包围之中，松材线虫病传入福建省只是时间的迟早问题。为了延缓该病的传入或一旦传入，能及时采取有效的控制办法，作者提出了预防性措施和可持续控制的对策，主要包括加强检疫措施，加强监测和监控，采取超前的预防控制措施。     

Enhancing resistance in Pinus radiata seedlings to terminal crook (Colletotrichum acutatum) using methyl jasmonate and ultraviolet‐C radiation

Colletotrichum acutatum is a fungal pathogen that causes terminal crook disease in radiata pine (Pinus radiata) seedlings in New Zealand forest nurseries. Symptoms of infection include malformation or death of the growing tip and a stiffening and thickening of the stem. Although the disease can be managed effectively using fungicides, the New Zealand forest industry is interested in alternative control options such as induced resistance. The aim of this study was to evaluate spray application of chitosan (1.4 g/l) or 2.25 mm methyl jasmonate (MeJA) and irradiation with UV‐C (2.16 kJ/m²) for their potential to induce resistance to terminal crook. The treatments were applied to 4‐month‐old seedlings at 1 week before pathogen inoculation. By the end of the experimental period (42 days after inoculation), there was 80% disease incidence in the controls, with 48% of seedlings exhibiting severe terminal crook symptoms. The most effective treatment (p < 0.05) was MeJA with 16% disease incidence and none with severe symptoms. UV‐C also significantly (p < 0.05) reduced infection with 52% incidence and 20% of seedlings exhibiting severe symptoms. Chitosan did not reduce disease incidence (72%) compared with the control (80%) but did significantly reduce (p < 0.05) disease severity with 28% exhibiting severe symptoms. MeJA was the only treatment that significantly (p < 0.05) reduced the detrimental effects of infection on seedling apical growth and stem diameter. To our knowledge, this is the first report demonstrating the potential for MeJA and UV‐C to control terminal crook in radiata pine.     

Pedicularis and Castilleja are natural hosts of Cronartium ribicola in North America: a first report

White pine blister rust disease, caused by the introduced pathogen Cronartium ribicola, has severely disrupted five‐needled pine ecosystems in North America. A 100‐year effort to manage this disease was predicated in part on the premise that the pathogen utilizes only species of Ribes (Grossulariaceae) as alternate hosts on this continent. The current study presents the first conclusive demonstration that some species in the family Orobanchaceae (Pedicularis racemosa and Castilleja miniata) are functioning as alternate hosts in a natural ecosystem of North America. This finding has implications for improving our understanding of epidemiology, pathogen adaptation and host–pathogen interactions within white pine blister rust.     

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。     

Dieback Disease of Pines with Special Reference to Corsican Pine Pinus nigra var. Calabrica Schn: III. Mycological Factors

The fungus Brunchorstia pinea Karst. v. H. is found to be consistentlyassociated with early stages of dieback disease in a numberof pine species. Inoculation of buds with conidial suspensions of the funguscauses typical disease symptoms to develop. The proportion ofsuccessful inoculations depends on the time of year, the locationof the tree, and its physiological condition. Vigorous treesare able to avoid infection, while weaker trees are very susceptibleto attack. It is suggested that though infection depends on low host resistance,Brunchorstia must be considered a primary pathogen since inall probability trees would survive and produce a crop wereit not for the activities of the fungus.     

Anatomical-based defense responses of Scots pine (Pinus sylvestris) stems to two fungal pathogens

We investigated the cellular responses of stem tissues of mature Scots pine (Pinus sylvestris L.) trees to inoculations with two fungal pathogens. The bark beetle vectored fungus, Leptographium wingfieldii Morelet, induced longer lesions in the bark, stronger swelling of polyphenolic parenchyma cells, more polyphenol accumulation and increased ray parenchyma activity compared with the root rot fungus, Heterobasidion annosum (Fr.) Bref., or mechanical wounding. Axial resin ducts in the xylem are a general feature of the preformed defenses of Scots pine, but there was no clear induction of additional traumatic axial resin ducts in response to wounding or fungal infection. The anatomical responses of Scots pine to pathogen infection were localized to the infection site and were attenuated away from bark lesions. The responses observed in Scots pine were compared with published studies on Norway spruce (Picea abies (L.) Karst.) for which anatomically based defense responses have been well characterized.     

Unravelling and managing fusiform rust disease: a model approach for coevolved forest tree pathosystems

Fusiform rust disease remains the most destructive disease in pine plantations in the southern United States. Our ongoing research is designed to identify, map, and clone the interacting genes of the host and pathogen. Several resistance (R) genes have been identified and genetically mapped using informative pine families and single‐spore isolate inoculations. In addition, we are mapping the first of many expected corresponding avirulence (Avr) genes in the fungal pathogen. The Avr genes condition avirulence/virulence and avirulence is required for an incompatible reaction (i.e., no‐gall development) to take place within an inoculated tree that carries resistance at the corresponding R gene. We provide an overview of our methodology for identifying and mapping R and Avr genes, an update of our current progress, and a brief discussion of two approaches for predicting R gene genotypes of uncharacterized parental trees and for estimating the efficacy of specific pine genotypes at various planting locations. This paper emphasizes the critical importance of controlled genetic materials of both the host and pathogen for elucidating the genetic nature of resistance and virulence in coevolved forest pathosystems.     

Incidence and distribution of white pine blister rust in the high‐elevation forests of California

In 2004–2006, a California‐wide survey was conducted to evaluate the incidence and distribution of Cronartium ribicola, cause of white pine blister rust (WPBR), in the high‐elevation white pine forests. WPBR occurrence varied considerably within and between regions, and little to no disease was found in the Basin and Range, eastern Sierra Nevada and Transverse and Peninsular mountain ranges. Field surveys revealed no evidence of rust on Great Basin bristlecone, limber or the southern subspecies of foxtail pine. Rust incidence for western white pine was highest in the North Coast region (42% of trees surveyed), followed by the Klamath (18%) and northern Sierra Nevada (14%). For whitebark pine, WPBR incidence averaged 24% in the northern Sierra Nevada; this was considerably greater than other regions where whitebark pine was found infected. Latitudinal trends in WPBR incidence (i.e. greater in the north) may correspond with earlier introductions of C. ribicola into these regions, reflecting the southward spread of the pathogen since its introduction from the north in the early 1900s and environmental conditions favourable for infection. Distance from inoculum sources and potentially host phenology may also be important factors influencing the distribution of C. ribicola.