人工酸雾对松萎蔫病的影响

<正> 许多科学家调查了松萎病发生和流行的规律。现已普遍认为松材线虫Bursaphelenchus xylophilus(Steiner et Buhrer)NickIe是该病的病原体。1971年Kiyohara和Tokushige用流行病学证实了松材线虫的致病力,并提出了引起松萎蔫病的一些其它因素,包括真菌和空气污染。目前,空气污染,特别是酸雨,是欧洲和北美一些国家引起森林衰退(Evans,1982;     

注药后黑松体内α-三噻吩含量测定方法

α-三噻吩(α-T)是一种植物源光活化毒素,注射入植物树干后,可用于防治松萎蔫病.介绍了以黑松苗1年生枝条木质部为材料,应用荧光分光光度计测定黑松体内α-T含量的方法.     

中国松萎蔫病病原线虫鉴定及诊断技术研究

松材线虫作为一种外来入侵物种,其致病机理尚不明确,致使该病的防治和控制工作进展缓慢。目前,该病的研究难点在于对其进行早期诊断和检疫。本文着重对我国松萎蔫病病原线虫鉴定及病害快速检测技术的研究现状进行评述,以期找到行之有效的检测方法。     

花绒寄甲防治松墨天牛林间试验初报

通过花绒寄甲防治松墨天牛林间试验,得出了松墨天牛在新干县被寄生死亡率64.6%,花绒寄甲生物防治效果明显。实验还说明,花绒寄甲寄生老龄幼虫。而且花绒寄甲是一种自然分布的生物天敌,可以在自然界繁殖,释放后随着时间推进,其种群量不断增加,活动范围亦不断扩大,对松褐天牛的寄生概率也会大大增加。因此,用花绒寄甲防治松墨天牛可以起到事半功倍的效果。     

药剂防治松突圆蚧的试验初报

试验采用50%杀扑磷、25%喹硫磷药剂防治松突圆蚧，结果表明：两种药剂的500倍液，防治效果均达80%以上，对雌蚧虫的杀伤力也远优于他种农药。     

两种杀虫剂对蜀柏毒蛾的生物活性和林间防效

在室内测定了5%甲维盐可湿性粉剂和5%阿维.杀铃脲悬浮剂对蜀柏毒蛾Parocneria orienta Chao 2龄幼虫的生物活性——触杀和胃毒作用,并进行了林间防治试验。室内试验结果表明,两种药剂对蜀柏毒蛾具有很强的杀虫活性和速效性,药后3 h的校正死亡率均在84%以上。林间防治试验结果表明,两种药剂对蜀柏毒蛾具有很好的防治效果,且持效期长。药后10 d,5%甲维盐可湿性粉剂的林间防效为90.73%～99.17%;药后15 d,5%阿维.杀铃脲悬浮剂的防效达87.76%～98.46%。建议在生产中使用5%甲维盐可湿性粉剂16 000～12 000倍液和5%阿维.杀铃脲悬浮剂4 000～3 000倍液防治蜀柏毒蛾和其他鳞翅目害虫。     

7种杀菌剂对苹果斑点落叶病防效试验

通过开展苹果斑点落叶病(Alternaria mali Roberts)田间药剂防治试验,表明所筛选的7种杀菌剂对苹果斑点落叶病都有很好的防治效果,其中25%丙环唑乳油0.033%浓度的溶液防效最佳,春梢期和秋梢期防效分别达89.84%和94.12%;而春梢期、秋梢期防效相对最差的10%多抗霉素可湿性粉剂0.1%浓度的溶液和1.8%辛菌胺醋酸盐水剂0.33%浓度的溶液,也达到85.83%和88.36%。这为指导大田防治和交替用药提供了科学依据。     

湿地松萎蔫病媒介昆虫松墨天牛及其携带线虫的研究

对湿地松萎蔫病媒介昆虫松墨天牛及其携带松材线虫、其它线虫的研究表明:湿地松萎蔫病木中羽化出的松墨天牛平均体长比马尾松上的短1.05 mm;从羽化开始到结束,天牛体长呈现减小的趋势,个体相差较大,体长最大的23.2 mm,最小的仅12.1 mm,相差11.1 mm,雌虫平均体长较雄虫长0.48 mm。萎蔫病木中的线虫在天牛体内表现为2种形态,线虫尾部呈指状或锥状;天牛体内的线虫有3种分布类型:所有线虫尾部为指状,所有线虫尾部为锥状,2个形态的线虫均有。湿地松松墨天牛中以尾部锥状线虫占多数,而马尾松的则以尾部指状线虫占多数。松墨天牛携带的线虫量与其体长无关,随着萎蔫病木的线虫量的增加呈上升趋势。线虫在松墨天牛体内的分布,以腹部为多,占整个虫体线虫量的75%以上,在利用松墨天牛预测湿地松萎蔫病时,取其腹部进行分离镜检即可。     

印楝素乳油对蜀柏毒蛾的生物活性及林间防效

在室内测定0.3%印楝素乳油对蜀柏毒蛾Parocneria orienta Chao的生物活性,并进行了林间防治试验.室内试验结果表明,0.3%印楝素乳油对蜀柏毒蛾具有很强的毒杀活性和一定生长发育抑制作用.林间试验结果表明,0.3%印楝素乳油对蜀柏毒蛾具有良好的防治效果.     

天水樱桃褐斑穿孔病发生与不同药剂防效评价

介绍了天水市樱桃褐斑穿孔病的发生现状与发生规律,分析了该病发生与气候因素和环境因素的关系。开展了田间不同药剂防效评价,提出了相应的农业防治结合化学防治技术的综合防控措施。     

松兰山景区松材线虫病综合治理研究

研究分析了浙江宁波市象山松兰山景区松材线虫病发生规律与防治效果。结果表明：只采取“封锁”措施，会使松材线虫病迅速爆发毁灭全林。从1992年到1998年，松兰山枯死松树从6株增到5893l株，增长了9820．8倍；采用皆伐松林防治松材线虫病并改造成板栗、杨梅的方法，会导致逆向演替，使松林最后成为以疏花野青茅为主的荒山。而采取综合防治措施就可有效地控制松材线虫病的危害。从1998年到2002年，松兰山枯死松树下降到137株，缩小了430倍，使松兰山仍然保持着葱郁的松林群落。     

保松灵（PEM）农药防治松材线虫病试验

试验表明，用３个类型保松灵在松树不同部位作低量喷雾能有效地抑制松材线虫病危害。喷洒保松灵的松树平均枯死率为２．３１％，比对照区松平均枯死率３６．３％净降３４％，经频率差异检验，Ｕ＝１６．５〉Ｕ０．０１＝２．５８，达到极显著水平。这个结果优于日本松材线虫病地面喷雾主药ＭＥＰ在象山试验的结果，而且用水量只为日本药的１／１０，平均每公顷农药成本只为日本药的１／３８。     

重灾区松材线虫病的治理试验

松材线虫病近距离传播是由松褐天牛自然扩散完成的。通过人工清理病死木结合化学防治,在中心疫区保住了1块松林。实践证明,人工清理后通过有效保护措施,能够控制松材线虫病。     

湖南省松材线虫病的预警及防控措施

该文分析了湖南省松材线虫病的发生背景,介绍了湖南省松材线虫病监测预警的方法和防控措施,并从实际出发对松材线虫病防治提出了建议.     

抗松材线虫病赤松组培再生植株田间生长表现

为了评价从日本引进的抗松材线虫病赤松通过无性快繁获得的再生植株在我国的生长状况.本研究对田间试种的抗病赤松6个家系12个无性系共688株再生植株进行跟踪监测.结果表明,抗病赤松0.5年生再生植株试种成活率明显低于2.5年、2年、1.5年及1年生再生植株;不同无性系间抗病赤松再生植株生长状况存在明显差异.其中,1#-A和5#-5无性系再生植株生长较好.菌根化造林试验表明,两种外生菌根菌美味牛肝菌(Be)和黄色须腹菌(R1)对抗病赤松1#-A5代、8代再生植株具有明显促生效果.此研究为今后抗病赤松再生植株造林育种提供了参考依据.     

Role of asymptomatic carrier trees in epidemic spread of pine wilt disease

To determine why pine wilt disease caused by the pinewood nematode (Bursaphelenchus xylophilus) recurs in the same pine stand even after thorough eradication of dead pine trees, the amount of oleoresin exudation from artificial wounds was measured from 72 Pinus koraiensis trees, highly susceptible to this disease, for 4 years. The amount of exuded oleoresin was rated from 0 to 4. All values obtained for each tree were summed at each measurement; thereby a cumulative curve was drawn to monitor the physiological condition of each test tree. Cumulative curves suggest that some pine trees that died had already been infected in the previous year or earlier and then had survived without any visible symptoms. If cessation of oleoresin exudation delays, and overlaps with activity of Monochamus alternatus, the vector beetle of pinewood nematodes, in the following season, such trees can be referred to as latent carriers or asymptomatic carriers. They could play a significant role as attractants for M. alternatus that could then transmit B. xylophilus to neighboring trees. Behavior of M. alternatus caged with several pine seedlings, only one of which acted as an asymptomatic carrier of B. xylophilus, confirmed this idea. The presence of asymptomatic pine trees, which harbored B. xylophilus nematodes or had reduced annual elongation, near stumps of newly dead trees in the study stand also substantiated this hypothesis.     

Retardation of pine wilt disease symptom development in Japanese black pine seedlings exposed to simulated acid rain and inoculated withBursaphelenchus xylophilus

Three- or 4-year-old Japanese black pine seedlings were exposed to simulated acid rain (SAR) at pH 3 for two months, then inoculated with a virulent isolate (S 10) of pinewood nematodes. The experiments were repeated three times in 1996–1998. The exposure to SAR killed no seedlings, and retarded the development of disease symptoms in the seedlings inoculated with nematodes. In the experiments in 1996 and 1997, however, cessation of resin exudation, and primary decrease in the xylem conductivity occurred earlier in the seedlings exposed to SAR than in those exposed to tap water as a control. These results imply that acid rain at pH 3 influenced an increase in some resistance of Japanese black pine seedlings to pinewood nematode, and that this improved resistance could potentially overcome damage caused by acid rain. The exposure to SAR did not have any significant effect on the water relations of the seedlings itself, suggesting that retardation of the symptom development after the exposure to SAR could not be attributed to the improvement in the water relations. This work was supported in part by a Grants-in-Aid for Scientific Research from the Japan Forest Technical Association (JAFTA).     

Genetic improvement in pine wilt disease resistance inPinus thunbergii: The effectiveness of pre-screening with an artificial inoculation at the nursery

Open pollinated progenies from 15 clones of Japanese black pine (Pinus thunbergii), that had been selected for their tolerance to pine wilt disease, were tested by artificial inoculation with pine wood nematode for six years at a nursery of Kyushu Regional Breeding Office. Family variations in the respective year were all significant. An analysis of variance across the six years’ tests confirmed highly significant effect of year and of families; however, the year by family interaction was significant also. Phenotypic and genetic variances estimated from each year’s result were fitted to a quadratic regression using their mean survival ratio as an independent variable. The variances were greatest at around 0.5 of the mean survival ratio. Estimated heritability showed a similar trend of change, whereas the peak of the expected amount of improvement shifted toward the lower survival range: around 0.4, where a greater selection differential was anticipated. It was concluded that a useful amount of genetic improvement that may be reduced by 30% due to the interaction, would be expected by prescreening seedlings where the mean survival ratio after inoculation was around 0.25 to 0.6.     

Relationship between the incidence of pine wilt disease and the drainage area

We examined the relationship between the incidence of pine wilt disease and moisture conditions in the stand level ofPinus densiflora Sieb. et Zucc. forests in the warm-temperate zone of the western part of Japan. For this analysis, pine trees killed by pine wilt disease were distinguished from the suppressed trees by their position in the layer of the pine forest stand. The drainage area, which is small in the upper part and large in the lower part of the slope, was adopted for representing the moisture conditions in the soil of the slope. The percentage of the pine trees killed by pine wilt disease increased as the size of the drainage area increased. This result suggested that the incidence of pine wilt disease tended to be high in areas with moist conditions. Pine trees attacked by the pinewood nematode die from extensive water deficit due to tracheid cavitations. Pine wilt disease mainly emerges in the summer when the soil water conditions become especially severe, and the radical water stress is thought to accelerate the disease. It was assumed that pine trees in the plots with the small drainage area resisted the influence of the attack of the pinewood nematode because pine trees in the plots with the small drainage area encountered long-term water stress and acquired drought tolerance. Pine trees in the plots with the large drainage area were presumed to be well established in the moist conditions and not to have acquired drought tolerance. The drought tolerance of pine trees was thought to be an important factor in resistance to pine wilt disease.     

湖北大别山五针松资源及保护

大别山五针松为中国大别山区特有树种，属国家Ⅰ级保护植物。本调查对湖北大别山自然保护区的大别山五针松资源现状、生境、种群特征及保护现状进行了调查，并提出了针对性保护举措和发展建议。