【作者】 赵敏；

【导师】 张磊； 王峰；

【作者基本信息】 东北林业大学 ， 林学， 2025， 硕士

【摘要】 自1982年首次在国内发现松材线虫(Bursaphelenchus xylophilus)病以来,该病害已迅速蔓延至全国多个省份,并表现出明显的北扩趋势,已扩散至辽宁、吉林等地,造成了严重的生态和经济损失。落叶松(Larix spp.)是东北地区主要针叶速生造林树种,明确落叶松家系抗松材线虫的生理生化与代谢响应可以为抗病落叶松的选育、防治策略优化及林业可持续发展奠定基础。本研究以落叶松家系以及落叶松无性系为试验材料,通过综合抗病评价,筛选高抗落叶松家系及无性系,同时将落叶松分为高抗、中抗和低抗三种类型,分析其生理生化、代谢产物等差异变化。主要研究结果如下:(1)高抗性落叶松筛选:通过对落叶松家系与无性系接种松材线虫试验,筛选到高抗家系5个(1317、1321、1311、1310、1305),中抗家系5个(1339、1336、1314、1316、1313)。筛选到抗病单株与无性系15个,其中高抗单株与无性系5个(1317-4、1317-3、1305-b、1305-a、1305-c),中抗单株与无性系10个(1317-2、1321-2、1321-5、1339-2、1321-4、1317-5、1326-b、1313-a、1302-a、1308-d)。(2)生理生化指标与抗病性:测定不同抗性落叶松家系的叶绿素(Chlorophyll)、超氧化物歧化酶(Superoxide Dismutase,SOD)、过氧化物酶(Peroxidase,POD)、可溶性糖(Soluble Sugar)以及可溶性蛋白(Soluble Protein)含量,发现高抗家系的叶绿素、SOD以及POD活性显著高于低抗家系。相比之下,低抗家系由于抗氧化能力较弱,代谢调控失衡,导致叶绿素降解严重,可溶性糖和可溶性蛋白异常积累,最终无法有效抵御松材线虫侵害。(3)萜类化合物与抗病性:α-蒎烯(α-Pinene)、蒈烯(Carene)、莰烯(Camphene)、异松油烯(Terpinolene)、β-蒎烯(β-Pinene)、石竹烯(Caryophyllene)、月桂烯(Myrcene)和长叶烯(Longifolene)在松树抵御松材线虫的过程中发挥了重要作用。高抗家系各萜类化合物在感病后期呈现上调趋势。其中,蒈烯和异松油烯在感病后期的含量显著高于低抗家系,这说明它们在松树后期防御松材线虫时发挥了重要作用。(4)激素及其相关物质与抗病性:通过超高效液相色谱(UPLC)对目标化合物进行分离,发现44种激素及其相关物质,其中12种代谢物在不同抗性落叶松间存在显著差异。1-氨基环丙烷羧酸(1-Aminocyclopropane-1-Carboxylic Acid,ACC)、反式玉米素核苷(trans-Zeatin Riboside)和二氢玉米素核苷(Dihydrozeatin Ribonucleoside)在高抗家系中含量较高,且变化趋势更为稳定,表明这些物质在正调控植物抗病过程中发挥了关键作用。脱落酸(Abscisic Acid,ABA)、3-吲哚乙腈(3-Indoleacetonitrile)、3-吲哚乙酰胺(3-Indoleacetamide)、赤霉素A9(Gibberellin A9)、对-玉米素(para-Topolin)、L-色氨酸(L-Tryptophan)和顺式玉米素(cis-Zeatin)通常在低浓度时有利于落叶松增强抗病性。(5)代谢途径与抗病性:高抗家系在抵御松材线虫侵染时,展现出高效的代谢调控能力。在病害初期高抗家系优先激活抗氧化酶系统,而在后期逐步增强次级代谢物的合成,从而提供持续有效的防御。此外,高抗家系在感病后期能保持较高的代谢物含量,从而进一步增强其抗病能力。更多还原

【Abstract】 Since the first detection of Bursaphelenchus xylophilus in China in 1982,the pathogen has rapidly spread to multiple provinces and demonstrated a clear northward expansion trend.It has reached Liaoning,Jilin and other places,causing serious ecological and economic losses.Larch(Larix spp.)is the main coniferous fast-growing afforestation tree species in Northeast China.Clarifying the physiological,biochemical and metabolic responses of larch families to pine wood nematode can lay a foundation for the breeding of disease-resistant larch,the optimization of control strategies and the sustainable development of forestry.In this study,larch families and larch clones were used as test materials.Through the comprehensive disease resistance evaluation,the families and clones of highly resistant larch were screened,and the larch was divided into three types:high resistance,medium resistance and low resistance,and the differential changes of physiology,biochemistry and metabolites were analyzed.The main findings are as follows:(1)Screening of highly resistant larch families and clones:Through the experiment of pine wood nematode inoculation on larch families and clones.Five highly resistant families(1317,1321,1311,1305,1310)and five moderately resistant families(1339,1336,1316,1314,1313)were screened.A total of 15 disease-resistant clones were screened,including 5 high-resistant clones(1317-4,1317-3,1305-b,1305-a,1305-c)and 10 medium-resistant clones(1317-2,1321-2,1321-5,1339-2,1321-4,1317-5,1326-b,1313-a,1302-a,1308-d).(2)Physiological and biochemical indexes and disease resistance:The contents of chlorophyll,antioxidant enzymes(SOD,POD),soluble sugar and soluble protein in different resistant larch were measured.It was found that the activities of chlorophyll and antioxidant enzymes(SOD,POD)in resistant varieties were significantly higher than those in susceptible varieties.In contrast,due to weak antioxidant capacity and unbalanced metabolic regulation,susceptible varieties can’t effectively resist the invasion of Bursaphelenchus xylophilus,resulting in serious chlorophyll degradation and abnormal accumulation of soluble sugar and soluble protein.(3)Terpenoids and disease resistance:Terpenoids(such asα-pinene,carene,camphene,terpinolene,β-pinene,caryophyllene,myrcene and longifolene)play an important role in the process of pine trees’resistance to Bursaphelenchus xylophiluss.The terpenoids in the high-resistance family showed an up-regulation trend in the late stage of infection.Among them,the contents of carene and terpinolene in the late stage of susceptibility were significantly higher than those in the low resistance families,indicating that they played an important role in the defense of pine against pine wood nematode in the late stage of pine trees.(4)Hormone and its related substances and disease resistance:Ultra-performance liquid chromatography(UPLC)was used to separate the target compounds,and 44 hormones and their related substances were found,among which 12 metabolites were significantly different among different resistant larches.Among them,1-Aminocyclopropane-1-Carboxylic Acid(ACC),trans-Zeatin Riboside and Dihydrozeatin Ribonucleoside were higher in high-resistant families,and the trend was more stable,indicating that these substances played a key role in the positive regulation of plant disease resistance.Abscisic acid(ABA),3-indoleacetonitrile,3-indoleacetamide,Gibberellin A9,para-Topolin,L-tryptophan and cis-Zeatin are usually beneficial to the disease resistance of larch at low concentrations.(5)Metabolic pathway and disease resistance:The disease-resistant varieties showed efficient metabolic regulation ability when resisting the infection of Bursaphelenchus xylophilus.Resistant varieties preferentially activate other defense mechanisms(such as antioxidant enzyme system)in the early stage of disease,and gradually enhance the synthesis of secondary metabolites in the later stage,thus providing sustained and effective defense.Disease-resistant varieties can maintain appropriate metabolite content in the later susceptible stage,thus further enhancing their disease resistance.更多还原