【作者】 苓建强；

【导师】 骆有庆； 许志春；

【作者基本信息】 北京林业大学 ， 森林保护学， 2011， 硕士

【摘要】 木犀科(Oleaceae)白蜡属(Fraxinus L.)树种是我国用材林、防护林、风景林等造林的优良树种。然而,花曲柳窄吉丁(emerald ash borer, EAB) Agrilus planipennis Fairmaire作为一种重要蛀干害虫,在我国辽宁、山东、天津等地严重危害白蜡树种,造成巨大损失。自从入侵北美以后,特别是近10年来,仅在美国密歇根州东南部危害致死白蜡树3000万株,截止2010年2月已传至美国东北部13个州和加拿大东南部的安大略和魁北克2个省。因为其幼虫隐蔽危害,在危害初期极难发现,控制困难且防治费用昂贵,当前最有效的措施是营造混交林,提供害虫的隔离环境。探讨白蜡属各树种的抗虫机制,有助于揭示花曲柳窄吉丁在不同树种间危害的原因,从而为花曲柳窄吉丁的区域性控制提供科学参考。本研究选择对花曲柳窄吉丁具有不同程度抗虫性的8种白蜡树,通过测定树皮、树枝组织结构物理性质的差异,树皮中内含物组成成分差异,以及树叶挥发性化合物种类与含量的差异,明确花曲柳窄吉丁对8种树种喜好差异,找出导致树种抗性差异的关键因子。评价白蜡树对花曲柳窄吉丁的抗性机制,主要研究结果如下：(1)在自然情况下,花曲柳窄吉丁对不同树种危害情况差异显著,绒毛白蜡和红梣受害非常严重,美国白蜡和欧洲白蜡受害较重,而宽果梣与水曲柳危害较轻,而大叶白蜡与白蜡树未发现危害。(2)主要树种绒毛白蜡在不同方向的受害并不显著,而不同高度差异极其显著,1-2m处的受害显著多于其它高度,在1.5m处危害最多,用正态分布可以很好的预测羽化孔在树干上的分布情况。(3)花曲柳窄吉丁的危害与树皮颜色无关,抗虫性与树皮厚度、粗糙程度、皮孔大小、紧实程度成反比,即树皮越厚、越粗糙、皮孔越大、树皮越紧密,越有利于花曲柳窄吉丁的危害。(4)树种内部组织结构中,导管面积、木化细胞个数、木化细胞半径、木化细胞面积与石细胞个数是逐步回归选择的与抗虫性相关密切的因子。其中,导管面积和木化细胞面积与抗虫性呈负相关；木细胞半径、石细胞数和木化细胞数与抗虫性呈正相关。(5)主要内含物中多酚、可溶性糖、还原糖、黄酮是与抗虫性相关密切的因子。其中,在不同抗性树种中,多酚含量在白蜡树、大叶白蜡和欧洲梣中的含量显著高于其它树种,多酚含量与抗虫性呈负相关；可溶性糖在各树种问差异并不显著,与抗虫性呈正相关；还原糖含量在白蜡树中显著高于大叶白蜡和红梣,而大叶白蜡和红梣又显著高于其余树种,还原糖含量与抗虫性呈负相关；黄酮含量在白蜡树和欧洲梣中的含量显著高于其它树种,多酚含量与抗虫性呈负相关。(6)测定8个树种在机械损伤前后挥发性化合物,各树种挥发物含量变化并不相同。正常情况下,抗虫性树种的醇类、萜类在种类与相对含量所占比例都较大；而感虫类树种脂肪酸类含量较大。在遭受机械损伤后,各树种释放的挥发物种类与含量都显著增加,不同树种中各类挥发物的释放有差异,抗虫类树种酯酮类增加幅度较大,感虫类树种醇类增幅较大,萜类在所有树种中都增加。更多还原

【Abstract】 The ash species trees (Oleaceae, Fraxinus L.) are admirable as commercial, protection, and landscape plants for coastal areas in China. Emerald ash borer (EAB) Agrilus planipennis Fairmaire is an important borer pest and damaged the ash tree in China such as Liaoning, Shandong and Tianjin. Since it was discovered in North America, it has killed more than 30 million ash trees in southeastern Michigan alone for decade.By February 2010, EAB infestations were known in thirteen states in the northeastern United States and two provinces in the eastern Canadian. There were limited EAB detection and control methods, and high costs, current objectives have shifted away from eradication to management of the pest. At present, the most promising long-term approach for reducing EAB populations and conserving ash in forested areas of North America is to build mixed forest. The exploration of the resistance mechanism of ash tree is contribute to reveal the reason why the pest outburst, which provide scientific basis of the regional control of EAB.There are selected 8 ash trees which are different degree resistance to EAB. The physical property of barks and organization characteristics of branchs, secondary inclusion and volatile compound in different ash species trees and the resistance to EAB were studied.We explained the preferences differences among different ash species trees, finding the key factors which cause the resistance differences. The main results are as follows:(1) The study found that the harm states were significant difference in EAB to different ash species trees. F. velutina and F. pennsylvanlca were seriously suffered, F. americana and F. excolsior were less than the first two species, however F. mandshurica、F. platypoda、F. rhynchophylla、F. chinensis were the least damaged or no damage.(2) The number of emergence holes of EAB were no significant differences in different directions in the F. velutina. There were significant differences in different height, the emergence holes at the 1 to 2m were much more than others. Further analysis showed that the number of the emergence holes at the 1.5m was the maximum. The normal distribution prediction functions were as follows:(3) The studies on relationship between bark morphology of fraxinus and insect resistance found that the damage of EAB has nothing to do with tree color, but is associated with the stomata size, roughness, the compaction degree and crack size.(4) The relationship between the characteristics and the resistance was studied. The results showed that Vessel areas, lignified cells numbers, lignified cells radius and areas, and sclerotic cell numbers were major factors in sequence from high relations to low relations. Meanwhile, Vessel areas and clerotic cell numbers were negative correlation, while lignified cell radius, lignified cell numbers and lignified cell numbers were positive correlation to the resistance.(5) The relationship between the inclusion of different ash species and the resistance to EAB were studied also. Polyphenol. soluble sugar, reducing sugar and flavone were major factors having intimate relationship with the resistance. The content of polyphenol in F. chinensis, F. rhynchophylla and F. excolsior wrer significantly higher than others, and the content of polyphenol had negative correlations with the resistance. The content of soluble sugar in different trees were not significant difference and had positive correlations with the resistance. The content of reducing sugar in F. chinensis was higher than that in F. rhynchophylla and F. pennsylvanlca, while all the three trees were much more than that in other species left, and the conten of reducing sugar had negative correlations with the resistance. The content of Flavone in the F. chinensis and F. excolsior were more than other ash species trees, and the content of flavone had negative correlations with the resistance.(6) The relationship of volatile compound in different ash species trees and the resistance to EAB were studied. The results showed that the changes of content in various ash species trees were diverse after mechanical damagement. Usually, the trees which had a high level content and kinds of alcohol and hemiterpene were high resistance, and the high content of fatty acid could cause susceptible to the pests. The kinds and contents of each ash species trees in the test were increasing significantly after mechanism damage, and different ash species trees had different releases, the content of esters and ketone were higher than others in the resistant trees, while for the susceptible trees the alcohol was a high quantity, the contents of hemiterpene increased among all trees.更多还原