华山松大小蠹危害与寄主华山松营养物质和抗性成分的关系

对秦岭林区遭受华山松大小蠹危害不同阶段的被害华山松韧皮部内的营养物质含量和酶活性变化进行了测定。结果表明,在华山松大小蠹和共生蓝变真菌危害初期,华山松韧皮部内的苯丙氨酸解氨酶(PAL)、多酚氧化酶(PPO)、超氧化物歧化酶(SOD)活性均显著提高,丙二醛(M DA)含量明显增加;但随着华山松大小蠹种群数量的增加和蓝变真菌对华山松韧皮部和木质部组织危害的加剧,韧皮部组织内的PAL、PPO和SOD活性逐渐降低,在枯立木阶段降至最低;与此同时,华山松韧皮部内的水分及蛋白质、糖类、粗脂肪、淀粉等营养物质含量,则随华山松大小蠹和共生蓝变真菌危害的加剧而不断减少。华山松大小蠹的入侵危害降低了华山松韧皮部的生理生化抗性,加速了其营养的分解。     

华山松大小蠹对9种植物挥发物的EAG和行为反应

选取5种非寄主挥发性化合物水杨醛、壬醛、三氯乙烯、二氯甲基甲醚和顺-3-己烯-1醇,4种寄主挥发性化合物β-蒎烯、(+)-3-蒈烯、β-石竹烯和(+)-α-蒎烯,应用触角电位仪和Y型嗅觉仪初步研究了华山松大小蠹成虫对这9种化合物的EAG反应和趋向反应。结果表明:雌虫对三氯乙烯、(+)-3-蒈烯和β-石竹烯,雄虫对壬醛、二氯甲基甲醚、(+)-3-蒈烯和(+)-α-蒎烯有明显的EAG反应;β-蒎烯、(+)-3-蒈烯和(+)-α-蒎烯对华山松大小蠹雌成虫有较强的引诱作用;三氯乙烯对雄成虫有较高的引诱率,且显著高于对雌成虫的引诱率。试验结果可为华山松大小蠹的行为控制技术研究提供借鉴。     

入侵害虫红脂大小蠹的研究进展

红脂大小蠹是我国近年来重要的入侵害虫。对红脂大小蠹的研究进展进行综述,提出加强检验检疫技术研究,防止扩散;加大信息素、天敌等生物因子的应用和科学育林等林业管理措施。     

西南地区茶藨生柱锈重寄生菌的分离与鉴定

华山松疱锈病是华山松Pinus armandi最严重的病害之一.为了利用重寄生菌对华山松疱锈病进行生物防治,对其病原菌茶藨生柱锈Cronartium ribicola的重寄生菌进行了分离和鉴定.依据柯赫氏三原则对分离得到的真菌进行鉴定,得到茶藨生柱锈的重寄生菌链格孢Alternaria spp.,镰刀菌Fusarium spp.,棒束孢Isaria sp.,拟盘多毛孢Pestalotiopsis sp.,木霉Trichoderma spp.及粉红单端孢Trichothecium roseum.经显微和超显微观察发现接种重寄生菌后锈孢子受到不同程度的破坏,且不同的重寄生菌对锈孢子有不同的作用方式.图3表4参15     

信息素防治红脂大小蠹的研究

应用中国科学院动物研究所提供的大小蠹类植物性引诱剂对红脂大小蠹DendroctonusvalensLeConte成虫进行诱杀效果和最大引诱距离试验。结果表明,该引诱剂对红脂大小蠹成虫有较强的引诱作用,有效诱捕距离不超过400 m;应用诱捕器诱杀后,林地红脂大小蠹平均侵入孔数下降77.1%;该引诱剂可用于对红脂大小蠹的监测和诱杀防治。     

超声提取华山松松针中莽草酸工艺优化

[目的]优选华山松松针中莽草酸超声提取法的最佳提取工艺。[方法]以莽草酸含量作为指标,考察了提取溶剂、超声功率、超声时间、料液比、超声温度、超声次数、原料粒度等对莽草酸提取率的影响,筛选出最佳的提取工艺。[结果]超声提取法的优化条件为：以重蒸水为提取溶剂,超声功率为200 W,超声时间75 min,料液比1∶60,超声温度60℃,超声次数2次,原料粒度为40目。在最佳工艺条件下,莽草酸提取率达36.651 2 mg/g。[结论]该优化条件可靠,适合华山松中莽草酸的提取。     

华山松有害生物灾害经济损失初步研究

在毕节地区华山松害虫种类调查研究中,应用常国彬等提出的林业有害生物灾害经济损失评估计算方法,对赫章县水塘林场2004年生物灾害经济损失进行计算.结果:直接经济损失L直接667万元,间接经济损失L间接在4000万元到1.3亿元之间.     

川东华山松死亡原因探讨 Ⅰ.酸雨

本文就酸雨与四川东部华山松大面积枯死的关系进行了论证。华山松严重发病区巫山县梨子坪林场5-8月份大气降水的pH值分别为6.06、5.80、6.05、5.78;土壤pH值为5.20-6.65。用pH为3.5、4.5、5.5的稀硫酸模拟酸雨试验,喷雾200 h、400 h后对华山松的生长量、干重、叶绿素含量无不良影响,实验证明四川东部华山松大面积枯死与酸雨无关。     

茶藨生柱锈菌致病性分化的初步研究

采用交互接种的方法对华山松疱锈病、红松疱锈病的病原菌茶藨生柱锈菌的致病性分化进行了研究。结果表明:(1)红松疱锈病的病原菌锈孢子只能侵染其本地的转主寄主植物东北茶藨子;(2)华山松疱锈病的病原菌锈孢子能转主侵染多种不同地区的茶藨子植物;(3)所有华山松疱锈病病原菌的锈孢子均不能转主侵染东北茶藨子;(4)初步认定马先蒿属植物不是华山松疱锈病病原菌的转主寄主。     

Response of bark beetles and their natural enemies to fire and fire surrogate treatments in mixed-conifer forests in western Montana

Four treatments (control, burn-only, thin-only, and thin-and-burn) were evaluated for their effects on bark beetle-caused mortality in both the short-term (one to four years) and the long-term (seven years) in mixed-conifer forests in western Montana, USA. In addition to assessing bark beetle responses to these treatments, we also measured natural enemy landing rates and resin flow of ponderosa pine (Pinus ponderosa) the season fire treatments were implemented. All bark beetles were present at low population levels (non-outbreak) for the duration of the study. Post-treatment mortality of trees due to bark beetles was lowest in the thin-only and control units and highest in the units receiving burns. Three tree-killing bark beetle species responded positively to fire treatments: Douglas-fir beetle (Dendroctonus pseudotsugae), pine engraver (Ips pini), and western pine beetle (Dendroctonus brevicomis). Red turpentine beetle (Dendroctonus valens) responded positively to fire treatments, but never caused mortality. Three fire damage variables tested (height of crown scorch, percent circumference of the tree bole scorched, or degree of ground char) were significant factors in predicting beetle attack on trees. Douglas-fir beetle and pine engraver responded rapidly to increased availability of resources (fire-damaged trees); however, successful attacks dropped rapidly once these resources were depleted. Movement to green trees by pine engraver was not observed in plots receiving fire treatments, or in thinned plots where slash supported substantial reproduction by this beetle. The fourth tree-killing beetle present at the site, the mountain pine beetle, did not exhibit responses to any treatment. Natural enemies generally arrived at trees the same time as host bark beetles. However, the landing rates of only one, Medetera spp., was affected by treatment. This predator responded positively to thinning treatments. This insect was present in very high numbers indicating a regulatory effect on beetles, at least in the short-term, in thinned stands. Resin flow decreased from June to August. However, resin flow was significantly higher in trees in August than in June in fire treatments. Increased flow in burned trees later in the season did not affect beetle attack success. Overall, responses by beetles to treatments were short-term and limited to fire-damaged trees. Expansions into green trees did not occur. This lack of spread was likely due to a combination of high tree vigor in residual stands and low background populations of bark beetles.