Altitude shape genetic and phenotypic variations in growth curve parameters of Larix kaempferi

To study the effects of geoclimatic variables of provenances on growth phenotypes and selected plus provenances,over 3000 trees of 22-year-old Larix kaempferi were evaluated from trials established in two climate zones for provenance selection and to explore the influence of climate variables on provenance performance.The material was replicated plantings of 84 open pollinated families from six provenances distributed in the mountains of central Japan.Provenance variation was observed in most age groups and the heritability of growth traits showed large differences.The phenotypic maximum value of height and diameter were significantly positive with altitude,and mean annual precipitation being important factors.Diameter at breast height growth was significantly negative with altitude and spring rainfall.The Ina provenance of relatively high altitudes,was well adapted to a variety of climates.Altitude might be the driving force for phenotypic and genetic variations and local adaptation.

Early evaluation of growth traits of Larix kaempferi clones

Early selection is an important method to shorten the breeding cycle for tree species, which may differ in the time for early selection. To evaluate the early selected time for Larix kaempferi, tree height and diameter at breast height of 57 L. kaempferi clones were measured over many different growth years. The results indicated that, except for age × clone interaction for diameter at breast height （P = 0.741）, there were significant differences among all variation sources （P 〈 0.01）. The coefficient of phenotypic variation ranged from 14.89 to 35.65% for height and from 19.17 to 23.86% for diameter at breast height in different growth years. The repeatability of height and of diameter at breast height among clones was high, ranging from 0.6181 to 0.8531 （height） and from 0.8443 to 0.8497 （diameter at breast height）, in different growth years. There were significant positive correlations between all pairs of growth traits except between height in the 2nd growth year and height in the 30th growth year; and between height in the 2nd growth year × diameter at breast height in the 30th growth year. With a comprehen- sive evaluation method and a selection ratio of 10%, L65, L1, L62, L9, L15, and L78 were selected as excellent clones in the 30th growth year. Their average values of height and diameter at breast height were 9.81 and 16.57% higher than the overall average, representing genetic gains of 6.46 and 13.99%, respectively. This study provides a theoretical foundation for the genetic improvement of L. kaempferi.

Isolation,expression and single nucleotide polymorphisms(SNPs) analysis of LACCASE gene(LkLAC8) from Japanese larch(Larix kaempferi)

Nucleotide diversity (pi) and linkage disequilibrium (LD) analysis based on SNP marker could provide a sound basis for choosing an association analysis method. Japanese larch (Larix kaempferi) is an important timber coniferous tree species for pulping and papermaking, but its high lignin content has significantly restricted it application potential. In this study, the LACCASE gene, that plays an important regulatory role for lignin biosynthesis, was selected as research target. The full-length cDNA and genomic sequences of the encoding LkLAC8 gene were isolated from the LACCASE expressed sequence tags of the Japanese larch transcriptome database using the rapid amplification of cDNA ends-polymerase chain reaction (RACE-PCR). The cDNA was determined to be 1940 bp, with an open reading frame (ORF, 1734 bp) that encoded a protein of 577 AA. This protein contains four highly specific Cu2+ binding sites and 11 glycosylation sites, thus belonging to the LACCASE family. The deduced protein sequence shared an 89% identity with the PtaLAC from Pinus taeda. A real-time PCR analysis showed that the LkLAC8 transcript was expressed predominantly in mature xylem, with moderate levels in the immature xylem, cambium and mature leaves, the lowest in the roots. Lastly, the genomic sequences of LkLAC8 in 40 individuals from six naturally distributed populations of Japanese larch were amplified, and a total of 201 SNPs (103 and 98 mutation types of transition and transversion, respectively) were detected; the frequency of the SNPs was 1/19 bp. Nucleotide diversity among the six populations ranged from 0.0034 to 0.0053, which suggested that there were no significant differences among the populations. The LD analysis showed that the LD level decayed rapidly within the increasing length of the LkLAC8 gene. These results implied that LD mapping and association analysis based on candidate gene may be feasible for the marker-assisted breeding of new germplasms with low lignin in Japanese larch.

Genetic variation of height growth rhythm between clones of Larix kaempferi × L. gmelini based on logistic models

Fifty-three larch interspecific hybrid clones（Larix kaempferi × L.gmelini） and their parent clones were used for growth curve analysis of height variations.The growth curves of the 55 clones were ＇S＇-shaped and 36 exhibited similar curves as the male parent.The coefficients of the logistic models were higher than 0.943,indicating that our results were effective in the simulation of the growth curves.ANOVA analysis showed significant differences in height of different clones （P／0.01）.Average date of maximum height growth was Day 173,and average duration of rapid growth lasted for 50 days.Annual average increase in height was 9.7cm d^（-1） and daily average increase was 0.2 cm.The ratio of GR to the total annual increase in height ranged from 51.2 to 68.8%,with the average being 59.8%.There was a positive correlation between k values and plant heights which benefited from the evaluation of early plant height.There was also a positive correlation between GR（growth stage）,GD（plant height） and annual increase in height.These results are informative to the evaluation of the elite clone selection and provide a theoretical basis for breeding and management.

Compatible taper and stem volume equations for Larix kaempferi(Japanese larch) species of South Korea

In this study, compatible taper and stem volume equations were developed for Larix kaempferi species of South Korea. The dataset was split into two groups: 80% of the data were used in model fitting and the remaining 20% were used for validation. The compatible MB76 equations were used to predict the diameter outside bark to a specific height, the height to a specific diameter and the stem volume of the species. The result of the stem volume analysis was compared with the existing stem volume model of Larix kaempferi species of South Korea which was developed by the Korea Forest Research Institute and with a simple volume model that was developed with fitting dataset in this study. The compatible model provided accurate prediction of the total stem volume when compared to the existing stem volume model and with a simple volume model. It is concluded that the compatible taper and stem volume equations are more convenient to use and therefore it is recommended to be applied in the Larix kaempferi species of South Korea.

Research on the relationship between stand productivity and site condition of Larix kaempferi

In this research, fi ve plots are selected based on stand storage and productivity of planted forest of Larix kaempferi (Japanese larch) as well as their relationship with factors such as forest age, site condition and stand den-sity. Through standard plot investigation and method of trunk analysis, systematic research is conducted on storage and productivity of the planted forest and their relationship with site condition. As shown in the research, produc-tivity of planted forest of Larix kaempferi in low latitude area is higher than that in high latitude area while stand productivity is higher in slight acid soil. Contents of potassium element in the soil have considerable in? uence on productivity of the Larix kaempferi forest.

Anti-inflammatory effects of natural volatile organic compounds from Pinus koraiensis and Larix kaempferi in mouse model

Natural volatile organic compounds(VOCs) extracted from conifers such as P. koraiensis and L. kaempferi have long been studied for their anti-oxidant, anti-proliferative, and anti-inflammatory effects. To evaluate the anti-inflammatory effects of VOCs from P. koraiensis and L. kaempferi, lipopolysaccharide(LPS) was administered to generate a mouse model for inflammation by the nasal route to the lungs and intraperitoneally to the whole body. VOCs of P. koraiensis and L. kaempferi were exposed to the mice by standardized wood panels with closed system. Increased levels of serum IgE and PGE2 were observed after exposure to dexamethasone and VOCs. We further determined the expression levels of inflammatory cytokine mRNA in the LPS-induced inflammation model by the reverse transcription quantitative polymerase chain reaction. Furthermore, the levels of cyclooxygenase-2, tumor necrosis factor-α, interleukin-1β, and interleukin-13 were determined in peripheral blood mononuclear cells. Those inflammatory cytokines and the key enzyme for inflammation cyclooxygenase-2 expression in PBMCs were strongly reversed by dexamethasone and VOCs. Lung tissues after nasal LPS exposure showed increased cytokine mRNA expressions which were suppressed by treatment with dexamethasone and VOCs. Furthermore, the damage induced by LPS was attenuated by dexamethasone and VOCs. In conclusion, the results from the present study indicate that VOCs of P. koraiensis and L. kaempferi have a therapeutic potential in the treatment or prevention of local and systemic inflammation due to their immunosuppressive effects.

Age-related trends in genetic parameters for wood properties in Larix kaempferi clones and implications for early selection

Wood properties are important traits that determine quality of structural wood. With the aim of performing efficient early selection for wood properties we investigated genetic variation in 20 Larix kaempferi clones aged from 4 to 15 years for four quality traits: wood density, wall thickness to lumen area, microfibrillar angle(MFA) and modulus of elasticity(MOE). We observed that age-related trends in overall means varied for differen traits: MFA decreased with the age, while the others generally increased with the age. Phenotypic variance always showed significant differences from the age of 8 years onward, with CVG ranging from 4% to 25%. Also clonal repeatability increased steadily until 9 years old and then kept medium or higher intensity(0.4–0.8). After the age of 6, genetic correlations were generally higher than phenotypic correlations. Estimates of early selection efficiency suggested that the optimal selection age for wood density was at age 5–6 years, while it was 9–10 years for the other traits. In combination with previous results we proposed a comprehensive early selection strategy for larch clonal breeding that involved selection based on nursery rooting ability, phenology, growth traits, and wood properties.

The Larix kaempferi genome reveals new insights into wood properties

Here,through single-molecule real-time sequencing,we present a high-quality genome sequence of the Japanese larch(Larix kaempferi),a conifer species with great value for wood production and ecological afforestation.The assembled genome is 10.97 Gb in size,harboring 45,828 protein-coding genes.Of the genome,66.8%consists of repeat sequences,of which long terminal repeat retrotransposons are dominant and make up 69.86%.We find that tandem duplications have been responsible for the expansion of genes involved in transcriptional regulation and stress responses,unveiling their crucial roles in adaptive evolution.Population transcriptome analysis reveals that lignin content in L.kaempferi is mainly determined by the process of monolignol polymerization.The expression values of six genes(LkC OMT7,LkC OMT8,LkL AC23,LkL AC102,LkP RX148,and LkP RX166)have significantly positive correlations with lignin content.These results indicated that the increased expression of these six genes might be responsible for the high lignin content of the larches’wood.Overall,this study provides new genome resources for investigating the evolution and biological function of conifer trees,and also offers new insights into wood properties of larches.

Mating patterns and pollen dispersal in a Japanese larch(Larix kaempferi) clonal seed orchard： a case study

Pollination dynamics highly determines the genetic quality of seed orchard crops. However, there is less research about the effect of mating patterns on seed productivity of orchard crops. So far, clonal seed orchards have been producing genetically improved seedlings used for most Japanese larch(Larix kaempferi(Lamb.) Carr.) plantations in China. In the present study, a total of 17 highly variable simple sequence repeat(SSR) markers were used for genotyping a progeny trial population consisting of 647 open-pollinated progenies germinated from seeds which were collected from 63 maternal clones with 140 potential paternal clones in a Japanese larch clonal seed orchard in China. Paternity analysis was used in the present case study in order to evaluate the level of paternal gametic contribution, estimate pollen contamination and selfing rates, and investigate pollination patterns,pollen dispersal patterns and the impact of mating patterns on seed productivity of orchard crops. We observed 93.7% of the success rate of the parental assignment, unequal paternal gametic contribution(0–12.4%) with 6.3% of the progenies derived from pollen contamination or unsampled pollen donors, and absence of evidence for selfing. We also found that pollination rate highly depended on the distance between pollen donors and maternal parents, the majority of the identified crossing(65.7%)occurred between clones within a 150-m radius, and large variations in growth performance existed among the paternal halfsiblings. Progeny growth performance(diameter at breast(DBH) and height(HGT)) was measured at Age-20 in order to investigate the impact of mating patterns on timber production of orchard crops. As either the paternal or maternal, two clones(i.e., clones Z38 and Z62) were identified to have produced progenies with higher average stem volume breeding values than that of all of the progenies. Specifically, the genetic gains for volume were 3.53% for the two clones as paternal parents, and 8.26% as the maternal parents at Age-20. Thus, both elite clones were ideal candidates for the construction of next-generation clonal seed orchards due to their synchronous reproductive phenology with greater crossing rate and higher genetic gain. These results improved the pedigree information to provide solid evidence of mating patterns for future design and effective management of seed orchards and for the development of viable long-term breeding strategies for other coniferous species.

Optimal Rotation Age of Larix kaempferi Pulpwood Plantation by Real Options Approach

The economic benefits and optimal rotation age of Larix kaempferi pulpwood plantation were analyzed under stochastic pulpwood price using real options approach in order to more effectively management to L.kaempferi pulpwood plantation in northern sub-tropical alpine area.Flexible rotation age and threshold price to different stand age of different site index plantation were developed.The result indicated that:1) the optimal rotation age of L.kaempferi plantation in site index 15,17,19,21 was 25,23,21 and 19 a,respectively,as the current pulpwood price equals 500 yuan·m-3,and the shortest rotation age was 23,20,17 and 15 a when facing to better price;and 2) Wait option should be the optimum strategy in any pulpwood price level when the stand age is lower than the shortest rotation age.

日本落叶松胚状体干化处理对萌发的影响

[目的]提高日本落叶松胚状体的萌发能力,优化日本落叶松良种繁育技术。[方法]本研究根据子叶数量和胚轴形态,对胚状体进行分类,并分别统计其萌发率;利用“滤纸容器法”对类型Ⅰ胚状体进行干化处理,统计其萌发情况。[结果]胚状体分为10种类型。类型Ⅰ胚状体萌发率为4.48%,其余类型胚状体难以萌发。干化处理14 d后,类型Ⅰ胚状体萌发率提高到69.43%,且具有干化响应的胚状体更易萌发。[结论]本研究表明日本落叶松胚状体干化处理后萌发率明显提高,为该物种良种繁育提供依据。

日本落叶松根际土壤水浸提液对林下山参的化感作用

目的探讨日本落叶松根际土壤水浸提液对林下山参的化感作用,为提高林下山参道地药材的品质以及规范化栽培与选址提供参考。方法研究了3种不同浓度(0.25、0.05、0.01 g·mL^(-1))的日本落叶松根际土壤水浸提液对林下山参种子萌发(发芽率、发芽势、发芽指数)、3年生林下山参显微性状(主根木质部、韧皮部、周皮及皮层)、人参皂苷含量[人参皂苷-Rg1、-Re、-Rf、-Rb1、-Rg2、-Rc、-Rb2、-Rb3、-Rd以及原人参三醇型人参皂苷(PPT)、原人参二醇型人参皂苷(PPD)和9种人参皂苷总量]的影响,结合液质联用技术对化感物质进行分析,并查阅相关文献对化感物质进行筛选。结果日本落叶松根际土壤水浸提液对林下山参的发芽指标有显著化感抑制作用,且随浓度增加抑制作用增强;化感作用会导致林下山参主根发生腐烂病变、皮层木栓化程度增强;化感作用对人参皂苷含量的积累具有显著促进作用。通过结果分析结合文献查阅,认为根皮素等5种物质可能是日本落叶松对林下山参作用的化感物质。结论结合上述研究结果,考虑到林下山参苗成活率、药材性状、劳动力成本、农药残留等因素,不建议在日本落叶松纯林下生产高品质林下山参。

日本落叶松种子园和优树自由授粉家系选择与利用研究

在甘肃小陇山沙坝落叶松/云杉良种基地,采用完全随机区组试验设计,对25个种子园的自由授粉家系和30个优树自由授粉家系在日本落叶松采伐迹地进行了更新造林试验,应用SPSS16.0和ASReml v3.0对造林9年生数据进行了统计分析。结果表明:不论是种子园自由授粉家系还是优树自由授粉家系试验林,树高、胸径、材积等性状家系间具有丰富的遗传变异,家系不同性状间具有显著的相关性,表型变异系数和遗传变异系数最大的是材积。种子园自由授粉家系试验林树高、胸径、材积的家系遗传力和单株遗传力为0.492、0.680、0.694和0.093、0.162、0.171,优树自由授粉家系试验林树高、胸径、材积的家系遗传力和单株遗传力为0.560、0.544、0.496和0.128、0.109、0.096,家系性状遗传力大于单株遗传力,家系性状受到中等以上的遗传控制,家系选择潜力大。根据种子园自由授粉家系亲本育种值指导初级无性系种子园去劣疏伐、改建1.5代种子园。以材积为主要选择指标,兼顾胸径、树高,在家系择基础上配合单株选择,从种子园自由授粉家系和优树自由授粉家系各选择20个优良单株构建高阶生产群体,高阶生产群体的预期遗传增益和现实增益分别达到25.74%、22.85%和122.59%、154.22%。从种子园自由授粉家系选择的50个单株作为构建遗传改良群体的应用材料,将优树自由授粉家系选择的45个单株作为育种群体的补充材料,构建遗传品质不断提高和遗传基础不断拓展的改良群体应用材料。

鄂西山区日本落叶松人工林全林整体模型研究与应用

为解决林分各测树因子及其生长模型之间的相容性问题,采用非线性度量误差联立方程组法建立鄂西山区日本落叶松人工林全林整体模型。研究结果表明,非线性度量误差联立方程组方法,能保证模型的相容性与无偏性;各林分因子的平均相对误差和相对均方误差均在6.5%以下,模型参数稳定性及预测精度均较高;建立的全林整体模型可用于不同初始条件的日本落叶松人工林林分生长收获预估、定量间伐作业设计以及林分密度控制图绘制。相关研究结果可为研究区日本落叶松人工林高效可持续经营提供科学参考。

鄂西日本落叶松人工林碳储量成熟龄研究

为研究鄂西山区日本落叶松人工林林分碳储量变化规律并确定碳储量成熟龄,利用8~41年生日本落叶松人工林87个标准地和249株样木树干生物量测定数据,以建立的单木树干生物量估算方程为基础,利用生物量扩展因子和碳系数推算出各林分单位面积碳储量,构建林分碳储量预估方程。结果表明:该区域日本落叶松人工林平均单株树干生物量为85.334 kg(2.694~395.214 kg),以胸径或树高为变量的一元和二元方程对单木树干生物量的拟合优度均在0.9以上,而二元方程拟合优度和精度更高;林分平均单位面积碳储量为77.465 t·hm^(-2)(4.573~172.512 t·hm^(-2)),其中单位面积碳储量为60~120 t·hm^(-2)的样地占总样地数的64.4%;利用Richards、Korf和Compertz 3个模型对林分碳储量进行预估,林分碳储量及其平均和连年碳积累量均十分相近,其中最大连年碳积累量和最大平均碳积累量分别为6.2和3.9 t·hm^(-2)左右,峰值林龄分别为13~15 a和23 a。Richards、Gompertz模型适于鄂西山区日本落叶松人工林碳储量的预估,该区域日本落叶松林分在中幼林(林龄15 a前)为碳的快速积累期,23 a为碳储量成熟龄。

日本落叶松种子园和人工林优树自由授粉家系试验林比较

【目的】为日本落叶松持续遗传改良提供应用材料和初级无性系种子园去劣疏伐提供依据。【方法】在甘肃小陇山沙坝国家落叶松/云杉良种基地,采用完全随机区组试验设计,在日本落叶松采伐迹地营造了30个优树自由授粉家系(Ⅰ)和25个日本落叶松种子园自由授粉家系(Ⅱ)试验林,试验林Ⅰ和Ⅱ均为15个区组,区组内家系株数2株×2株配置,株行距1.5 m×1.5 m。【结果】种子园自由授粉家系试验林胸径、树高、材积平均达到(6.474±1.474)cm、(6.429±0.885)m、(1.274±0.599)×10^(-2) m^(3),显著高于人工林优树自由授粉家系试验林胸径、树高、材积的13.99%、9.18%和26.94%(P>0.05)。种子园自由授粉家系胸径、树高、材积的表型变异系数和遗传变异系数为13.76%、22.76%、47.02%和4.52%、1.96%、9.54%,家系遗传力和单株遗传力为0.729、0.544、0.735和0.214、0.156、0.210;优树自由授粉家系胸径、树高、材积的表型变异系数和遗传变异系数是21.92%、26.82%、60.03%和4.36%、2.91%、9.76%;家系遗传力和单株遗传力依次为0.645、0.626、0.598和0.169、0.175、0.148;优树自由授粉家系试验林胸径、树高、材积性状的遗传变异比种子园自由授粉家系更加丰富。种子园自由授粉家系子代测定回向选择指导初级无性系种子园去劣疏伐升级1.5代种子园,入选单株直接无性繁殖利用或作为高阶育种应用材料,种子园自由授粉家系按照40%的入选率,入选10个家系,入选家系平均胸径、树高、材积为6.6148 cm、6.8420 m、0.0143 m^(3),在家系选择的基础上,选择50个单株,单株入选率3.58%,入选单株平均胸径、树高、材积达到9.16 cm、7.60 m、0.026 m^(3);入选家系和单株材积的平均遗传增益达到9.39%和22.09%。优树自由授粉家系和单株入选率为30%和3.01%。【结论】种子园自由授粉家系试验林入选单株预期遗传增益为22.09%,可作为高世代种子园营建和进一步遗传改良的应用材料,并直接进行无性系繁殖利用,使育种早见成效。优树自由授粉家系试验林入选单株预期遗传增益为20.66%,补充遗传改良材料,不断丰富和拓展遗传改良材料的遗传基础,确保长期稳定的遗传增益和持续遗传改良。

日本落叶松遗传变异分析及优良家系无性系选择

为探索日本落叶松遗传变异规律及选择优良家系无性系,以内蒙古自治区赤峰市旺业甸实验林场的59个日本落叶松无性系测定林和81个日本落叶松家系子代试验林为研究对象,测定其树高,对其进行方差分析和变异分析。结果表明,日本落叶松无性系和家系树高性状存在丰富的变异,变异系数范围分别为17.84%~20.67%和24.68%~31.19%。方差分析表明,每一年,无性系间和家系间均存在显著差异,重复力和遗传力范围分别为0.482~0.494和0.793~0.819,属于中等重复力和高遗传力。以20%的入选率为标准,最终选择出12个优良无性系和16个优良家系,无性系现实增益和家系现实增益范围分别为5.73%~16.48%和7.59%~15.35%。

日本落叶松自由授粉家系选择和无性繁殖利用

【目的】为加速日本落叶松良种转化利用效率,从源头提高造林质量,助推“碳达峰”和“碳中和”目标早日实现,进一步为遗传改良提供材料。【方法】在甘肃小陇山沙坝落叶松/云杉国家良种基地167林班30 a日本落叶松人工林主伐迹地,采用完全随机区组试验设计:按株行距1.5 m×1.5 m,4×4株小区,5次重复对36个日本落叶松种子园自由授粉家系进行更新造林试验。试验林17 a生胸径、树高、蓄积、生物量、碳密度等性状值采用spss16.0进行分析。通过家系性状遗传变异分析,以胸径为选择对象,选择出胸径最高的家系,在家系选择的基础上,配合单株选择。【结果】家系间胸径、树高、蓄积、生物量、碳密度差异达显著水平(P<0.05),且试验林胸径、树高、蓄积、生物量、碳密度等性状间呈极显著正相关关系(P<0.01)。这些性状表型变异系数和遗传变异系数依次为:27.23%、17.02%、60.34%、18.09%、18.08%和3.14%、1.73%、7.49%、2.03%、2.02%。表型变异系数远大于遗传变异系数,表明落叶松生长性状不仅受遗传因素影响,还易受环境因子影响,家系间存在着丰富的遗传变异,遗传改良潜力巨大。以胸径为主按30%的入选率,入选家系11个,入选家系胸径、树高、蓄积、生物量、碳密度的家系遗传力为0.520、0.455、0.542、0.451、0.448,预期遗传增益和现实增益分别达到3.32%、1.59%、7.56%、1.84%、1.83%和6.39%、3.49%、13.94%、4.08%、4.08%,家系性状选择强度在0.21~0.23间。在家系选择的基础上,配合选择单株55株,单株入选率2.15%,选择强度在1.37~2.45间。入选单株胸径、树高、蓄积、生物量、碳密度的遗传增益和现实增益分别是3.00%、3.73%、8.86%、1.46%、0.70%和56.53%、23.31%、145.25%、29.16%、29.16%。【结论】日本落叶松家系和家系内存在着丰富的遗传变异,而且生长易受环境因子影响,选择潜力大。在家系选择的基础上配合单株选择,将入选单株嫁接或者扦插营建采穗圃,早期无性系繁殖利用,进一步为遗传改良提供了应用材料。

松材线虫侵染对日本落叶松生理指标的影响

通过测定光合色素含量、渗透调节物质、苯丙氨酸解氨酶和抗氧化酶系统的动态变化,从生理生化角度探究日本落叶松对松材线虫侵染的响应规律。以3年生日本落叶松盆栽苗为实验材料,采用人工皮接法接入2 000条松材线虫,于接种后第0、5、10、20、30天时收集并测定针叶内叶绿素含量、可溶性蛋白含量、抗氧化酶[超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)]活性和苯丙氨酸解氨酶(PAL)活性等指标。结果表明:日本落叶松接种点上部和下部均检测到大量松材线虫,且下部线虫数极显著高于上部(P<0.01)。叶绿素a、b含量均在第10天时出现明显下降,随后开始上升,与对照组无显著差异。可溶性蛋白含量在接种10 d后开始逐渐上升,且显著高于对照组(P<0.05)。接种松材线虫后,SOD活性显著上升,各时间点均极显著高于对照组(P<0.01);CAT活性先小幅下降,后逐渐升高,于30 d时极显著高于对照组(P<0.01);POD活性表现为先降低后升高,且5 d后迅速升高,各时间点都显著高于对照组(P<0.05)。PAL活性呈现先升高后降低的变化规律,接种后10、20 d活性都显著高于对照组(P<0.05)。日本落叶松被松材线虫侵染后,叶绿素含量、可溶性蛋白含量、抗氧化酶和PAL活性变化与其抗病性存在密切关系,研究结果可以为日本落叶松对松材线虫抗性品系筛选和抗病机理提供参考。