感染松材线虫病的思茅松林择伐木外观判定初探

通过观察思茅松在12月至翌年1月感染松材线虫病的外部特征，得出思茅松感病后的主要外部特征和区别于其他松树的感病特点，并提出择伐感病思茅松时在外观特征上的判定标准和处理建议。     

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。     

松材线虫病的潜伏侵染及松墨天牛传播途径

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。     

辽宁省防范松材线虫病入侵管理对策探析

该文介绍了松材线虫病病原、传播媒介及危害症状,以及在辽宁省的适生性、感病寄主植物、传播媒介,分析了松材线虫病可能入侵的途径等,提出了防范松材线虫病入侵的行政管理、检疫措施、监测预警等方面的管理对策。     

大连地区松材线虫病林间接种试验初报

通过2次人工接种试验来模拟大连地区感染松材线虫病林木发病的全过程,实验表明:大连地区松材线虫病的感病松木过程为感染枝先开始枯萎,然后整株树木失绿枯萎,然后整株树木枯死。大连地区感病松木存在2种外部症状类型,一种是当年枯死,一种是越年枯死。当年枯死的病程是8~20周,6月份以前发病死亡的基本都是越年枯死感病木。     

沈阳市油松松材线虫病发病规律观察

为了明确自然状态下油松感染松材线虫后的发病规律，采用直接观察法、流脂观察法、松材线虫分离鉴定等方法对沈阳市东陵公园内约70 a生油松大树发病过程及症状特征进行了持续性观察。结果表明：感病油松表现为当年、越1年和越2年枯死，以越1年枯死类型为主。油松受害初期，不同小枝的同一时间受害症状不同，枯死针叶在树冠上无规则星状分布，受害后期，树冠下小枝发病过程整齐统一。油松枯死5～6个月后针叶开始脱落。枯死油松胸径以下树皮上多有天牛危害痕迹，无流脂现象。该结果可为东北地区松材线虫病的防治提供依据。     

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。     

松材线虫入侵对马尾松树光合特性的影响

[目的]明确松材线虫入侵对马尾松树针叶光合特性、光合响应曲线、主要光合响应指标及碳氮元素含量的影响,以期在光合生理水平上提供松材线虫病的早期快速诊断技术,为林业管理者采取快速防治措施提供科学的理论依据。[方法]本研究选取健康期、感病中期和感病末期马尾松树为研究对象,利用Li-6400XT便携式光合测定仪和稳定同位素质谱仪,分别测定不同感病阶段马尾松树针叶光合特性及所测针叶样品的C%、N%和δ~(13)C含量。[结果]健康马尾松树在松材线虫胁迫条件下,可显著降低其针叶的净光合速率、蒸腾速率及气孔导度,其数值大小均表现为:健康期感病中期感病末期;不同感病阶段马尾松的暗呼吸速率数值之间的差异也达到极显著水平,其数值的大小表现为:感病中期健康期感病末期;健康期马尾松的光补偿点显著低于感病中期的光补偿点,但是其光饱和点显著高于感病中期的光饱和点。此外,不同感病阶段马尾松树针叶的平均C素含量变化不大,但平均N素和平均δ~(13)C含量则会显著下降。[结论]松材线虫侵染健康马尾松树后,可降低其对外界光照条件的适应能力,致使其光合特性显著下降;感病马尾松树针叶N素损失是导致马尾松光合能力显著下降的一个主要原因;感病马尾松树针叶气孔导度下降是导致其针叶δ~(13)C含量下降的主要原因,同时亦说明松材线虫的入侵会显著降低马尾松树针叶的水分利用效率。     

松材线虫致病性最佳接种量的研究

松材线虫是引起松树死亡的一种毁灭性病害的病原。为了研究松材线虫的致病性,该文对松材线虫的接种量进行研究,对3年生黑松苗接种松材线虫后的发病程度进行了等级划分以及发病等级的描述。3年生黑松苗,接种松材线虫LN001后,每株接种量为10000条时,发病率、感病指数、死亡率3个指标均达到最大值。接种松材线虫LN002后,每株接种量为8000条的松苗,在接种第47d时,感病指数达到100。3年生黑松苗接种松材线虫8000~10000条,为适合进行松材线虫接种试验的接种量。     

本溪市松材线虫病集中普查情况分析

1 本溪市松材线虫病发生情况及趋势松材线虫病是重要的林业检疫性有害生物,是我国最具危险性和毁灭性的林业有害生物。松树感染松材线虫后40天即可死亡,成片松林感病后2~3年即可毁灭。具有致病力强、感病树木死亡速度快、传播迅速、防治难等特点,素有“松树癌症”之称,是国务院高度重视和国家林业局严格防控的主要林业有害生物。     

Susceptibility of Coulter pine (Pinus coulteri) to western dwarf mistletoe (Arceuthobium campylopodum) in southern California

The susceptibility of Coulter pine (Pinus coulteri) to western dwarf mistletoe (Arceuthobium campylopodum) was evaluated in southern California. Eight stands infested with western dwarf mistletoe and dominated by Coulter and Jeffrey pines (Pinus jeffreyi) were sampled. Infection of Coulter pine was evaluated using circular plots established around large, severely infected Jeffrey pines and with rectangular transects. A total of 25 plots and 10 transects were sampled. In each plot and transect, live trees > 5 cm in diameter at breast height (1.4 m above the ground) were assigned a dwarf mistletoe rating (6‐class system). Nearly 600 Jeffrey pines and more than 400 Coulter pines were evaluated. Infection of Jeffrey and Coulter pines in the plots and transects averaged 96% and 97%, respectively. These data indicate that Coulter pine should be classified as a principal host of WDM and not as a secondary host as previously reported.     

Long‐term survival and non‐vector spread of the pinewood nematode,Bursaphelenchus xylophilus,via wood chips

The pinewood nematode, Bursaphelenchus xylophilus, is the causal agent of pine wilt disease and is transmitted to new host trees by beetles of the genus Monochamus. The increasing interest in imported wood chips from North America for paper production and energy purposes and the corresponding phytosanitary risk of non‐vector transmission of B. xylophilus has been discussed since 1984, the year of the first interception of B. xylophilus in wood chips in the European Union. The long‐term survival of B. xylophilus in wood chips and its non‐vector spread from infested wood chips to non‐infested trees were studied. Pinus sylvestris logs were inoculated with a suspension of B. xylophilus to produce infested wood chips. During the long‐term storage test, B. xylophilus in P. sylvestris wood chips were examined. Four variants, including sealed and openly stored wood chips at both 15°C and 25°C, were studied. For the test of non‐vector spread, B. xylophilus ‐infested wood chips were placed on three‐ to four‐year‐old P. sylvestris saplings under different conditions. Bursaphelenchus xylophilus survived for more than 1 year at both temperatures in the sealed wood chips, which was significantly longer than for the openly stored variant at 25°C. Temperature, tree condition and wood chip location all influenced non‐vector spread through wood chips. Of the 480 trees that were in contact with infested wood chips and showed clear symptoms of pine wilt disease, B. xylophilus were extracted from 42 pines at 25°C and one pine at 15°C. The highest B. xylophilus infestation rates resulting in clear pine wilt disease symptoms (75%) were found in infested wood chips directly attached to stem‐wounded trees at 25°C. However, more variants exhibited B. xylophilus infestation at this temperature; trees with stem or root injuries plus direct contact with infested wood chips to the wounded part were primarily affected. Moreover, non‐vector spread was also detected in stem‐ and root‐injured pines without any direct contact with infested wood chips. Our results confirmed that B. xylophilus can survive for long periods in wood chips and can be transmitted from infested wood chips to damaged trees, but the likelihood of such PWN establishment should be low compared to spread through vectors. These findings must be considered in the pest risk analysis of B. xylophilus, and studies using outdoor trials should be carried out to complete this pest risk analysis.     

Responses of water-stressedPinus thunbergii to inoculation with avirulent pine wood nematode (Bursaphelenchus xylophilus): Water relations and xylem histology

The effect of water-stress conditioning on water relations and histological features ofPinus thunbergii Parl. inoculated with avirulent isolate ofBursaphelenchus xylophilus (Steiner and Buhrer) Nickle, pine wood nematode, were investigated. Pines were kept under 8 days cycle of severe water stress. One-half of the water-stressed pines died as a result of infection by avirulent pine wood nematode and water stress tended to induce increased susceptibility and/or decreased resistance of pines to avirulent pine wood nematode. In dead pines, the water conducting function of xylem was lost, and all of the parenchyma cells died. In surviving pines, the xylem hydraulic conductivity and the xylem water content were significantly reduced (12 to 23% and 77 to 83%, respectively) compared to controls. Safranin dye perfusion of excised axis stem segments indicated that the water conductance was limited to the very narrow peripheral area of xylem. Embolism caused by cavitation in the tracheids occurred in the central part of xylem and in that dysfunctional region of the xylem the axial parenchyma cells surrounding the epithelial cells, and ray parenchyma cells partly degenerated but the epithelial cells survived. The disruption of tracheid shape observed in surviving pines indicates that avirulent pine wood nematode temporarily disturbed cell division of the cambium. Considering the differences in responses between dead pines and surviving pines after inoculation with avirulent pine wood nematode, the death of water-stressed pines apparently resulted from death of cells, in particular the vascular cambium and the loss of xylem hydraulic function by cavitation.     

萧氏松茎象幼虫食性、危害及防治技术

萧氏松茎象幼虫在南岳衡山主要危害华山松，在寄主树干基部皮层和裸露的根皮层蛀食，造成大量流脂，导致生长衰弱，引起松墨天牛暴发；同时取食新鲜松脂，越冬后的幼虫仅靠取食新鲜松脂就能正常发育。幼虫只危害健康松树，不危害衰弱木、枯立木，说明其蛀食危害与松树能否分泌松脂有关。在被害松林内，单株幼虫数在0～6头之间。幼虫在有虫株之问分布较均匀，1头／株的占82．5％，平均为1．38头／株，且单株虫口密度与树干基部直径呈明显正相关。混交林和非松树林分能阻止该虫扩散。5—10月间在幼虫危害期和蛹期，采用人工清除幼虫和蛹的方法可有效控制该虫危害，而采用化学药剂防治该幼虫，效果不明显。     

松材线虫病感病松树中致萎毒性物质的研究

本研究用我国自然感染松材线虫病的15年生以上黑松和马尾松以及人工感染松材线虫病的3年生黑松的木质组织进行萃以和粗提纯，方法为高压蒸煮法和氯仿碱法。生物测定结果显示，有致萎活性的毒性物质仅存在于自然感病未死的黑松和马尾松以及人工感病未死的黑松木质组织中。自然感病死后1年的黑松和马尾松以及健康松树不中含有这些毒性物质。通过气相色谱－质谱联用仪（GC／MS System）对上述木质组织萃取物作定性分析发现，自然感病未死的黑松、马尾松和人工感病未死的黑松有致萎活性的萃取物中均含苯乙酸和2－甲氧基肉桂酸，自然感病死后1年的松树和健康松树中则无。而在健康松树和感病松树中都发现有苯甲醛存在。表明毒性物质与苯乙酸和2－甲氧基肉桂酸有关，苯甲醛则是松树正常的代谢产物。苯乙酸和2－甲氧基肉桂酸均为酚类化合物，是植物体内重要的次生物质。说明感病松树中的毒性物质是松树组织由于松材线虫侵染而产生的异常代谢产物，应称之为致萎毒性物质。     

红脂大小蠹诱导油松树干挥发性单萜相对含量的变化

使用Porapak Q吸附剂,采用动态顶空的吸附方法,连续抽取11个不同阶段的对照、损伤与虫害油松的挥发物成分.运用GC、GC-MS与图谱峰面积进行挥发物成分定性与单萜相对含量的定量分析.与对照和损伤油松相比,虫害油松含有高比率的(+)-α-蒎烯(超过90％)和月桂烯,但(+)-3-蒈烯,(-)-β-蒎烯,莰烯和柠檬烯含量较低.(+) -3-蒈烯含量对照和损伤油松高于虫害油松(低于4％).(+)-3-蒈烯含量从损伤4天后的最低水平逐渐恢复到对照油松中含量水平.(-)-β-蒎烯和柠檬烯在不同处理的油松中含量相近,但在接入雌雄虫后3个处理间存在显著差异.尽管目前不确定我国的红脂大小蠢是否在危害油松后释放信息素,但研究表明红脂大小蠢可能会利用各种单萜成分细节上的变化作为化学信号,从而实现寄主的选择和种群聚集.本研究对于揭示油松抗性机制,完善红脂大小蠢的监测与防控技术体系具有重要意义.     

TAXONMIC SIGNIFICANCE OF SYMPTOM CHARACTERISTICS AND AECIOSPORES SURFACE STRUTURE OF PINE NEEDLE RUST

INTRoDUrnoNRneneedlerustdiseasecausedbyCo-leosPoriumsPP.seriouslyharmspinetreesthatarelessthanloyearsold.Sincel847,LeviellsetuPCoIeosPoriumgenus,sofarintheworld,morethan9Ospeieshavebeendescribed.AInOngthem,8speCiesareautoec1ous,1speciesarendcI-OCyclic,and3speciesaredenti-cyclic,theremainingareheteroeciousI7'l6l.fuStorically,theclassificahonofColeosPo-riumisnotveryclear.lntfadihonalclassifica-hon,genusofCoIeosPorilunwasdecidedbythemorpholOgyofteliosPOres,andspecieswasdecidedbyaltem…     

不同松树感染松材线虫后NO和核酸酶变化与其抗病性的关系

以黑松、马尾松和火炬松为研究对象,对其接种松材线虫后4,12,24,48,72,96和120 h的NO和核酸酶的活性进行测定.3种松树接种松材线虫后,针叶内NO平均含量的积累为火炬松＜马尾松＜黑松,这种差异在12 ～48 h尤为明显;48h后较其割伤处理(CK1)的增加幅度为火炬松＞马尾松＞黑松.同时3种松树接种后的核酸酶变化趋势存在差异,单链核酸酶活性在4～48 h为火炬松＞马尾松＞黑松,而火炬松双链核酸酶活性在4～96h时却一直低于马尾松和黑松,这表明不同松树体内单链或双链核酸酶的活性变化与其抗病性有关.且3种松树在接种松材线虫后,表现出症状的时间顺序为黑松最早,马尾松次之,火炬松最晚.这表明NO和核酸酶的变化与松树感染松材线虫后的病程发展密切相关.     

Effect of drying methods on the discoloration of three major domestic softwood species in Korea

1 Introduction Three major softwood species in Korea are Japanese pine (Pinus densiflora), Korean pine (Pinus koraiensis) and larch (Larix leptolepis) which have been used for traditional buildings and furniture for a long period of time. They are easily discolored due to drying and UV irradiation. It has been observed that the discoloration varies with different drying methods and the extent of UV irradiation (Mottonen and Luostarinen, 2001; Kang, 2003). To prevent beech from discolorat…