日本落叶松咖啡酸-O-甲基转移酶基因 LkCOMT的克隆及单核苷酸多态性分析

依据日本落叶松转录组数据库检测到的咖啡酸-O-甲基转移酶(COMT)基因ESTs序列设计引物,分离得到一个编码该酶的新基因。其cDNA克隆全长为1 350 bp,包含长度为1 092 bp的开放阅读框,可编码364个氨基酸残基。序列分析显示,所推导的蛋白质氨基酸序列包含COMT基因5个所特有的保守元件,与海岸松PpCOMT的蛋白质氨基酸序列同源性达94%。在此基础上,利用DnaSP5.0软件对日本落叶松40株基因型个体的LkCOMT序列进行了单核苷酸多样性SNPs分析,共检测到92个SNP位点,SNP发生频率为1/17 bp,多样性指数π_T为0.007 80。在这些SNPs中,65个属于转换,27个属于颠换。在外显子区域,共检测到58个SNP位点,其中37个为错义突变,21个为同义突变。研究结果为日本落叶松基因标记辅助育种提供了理论基础。     

日本落叶松EST-SSR标记挖掘及特征分析

基于日本落叶松转录组测序(RNA-seq)结果,利用SSRIT工具查找SSR位点,检测到1 788个EST-SSR位点,平均长度是17.5 bp。进一步统计分析发现在落叶松中重复类型SSR位点出现次数最多的是六、三核苷酸,其余依次是五、二、四核苷酸重复类型;同时检测到656种重复基元类型,种类丰富。用Primer Premier 5.0设计500对引物,随机合成102对,以红豆杉科、柏科、松科材料为模板进行检测,结果显示在红豆杉科和柏科里的扩增率分别为95%、50%;在松科不同属的通用性为落叶松属99.01%、黄杉属67.4%、雪松属63.8%、冷杉属67.4%、云杉属70.2%和松属75.7%。利用101对SSR引物对7种不同落叶松品种亲缘关系进行了分析,获得79个多态性位点,在遗传相似系数0.69处将其区分为4个类群。     

甘肃小陇山日本落叶松人工林土壤优势真菌多样性探讨

为了初步了解国家级自然保护区小陇山沙坝地区日本落叶松人工林夏季土壤真菌生态分布与多样性情况,利用全球卫星定位系统(GPS),在天水小陇山日本落叶松栽种区沙坝地区抽取10块日本落叶松人工林样地,采用稀释平板法对该地区日本落叶松人工林土壤真菌进行分离计数,结果表明该区土壤真菌数量较少。并分离鉴定出4个优势属,其中青霉属(Penicillium)和曲霉属(Aspergillum)是该地区最常见的类群。为了进一步了解该区日本落叶松人工林土壤质量与土壤真菌数量及多样性的反应机制,对该区日本落叶松人工林真菌区系又进行了多样性分析:不同采样区多样性指数波动较大,物种多样性较低,土壤真菌数量较少。     

长白落叶松人工林可燃物碳储量分布及燃烧性

对小兴安岭长白落叶松人工林可燃物进行分层分类型调查,比较其碳储量垂直分布,分析从未成林地到成熟 林林火种类、行为和燃烧性,据此评估森林燃烧性等级,并提出可燃物处理和营林防火措施。结果表明:未成林碳 储量仅87.660 t/ hm2 ,但各层可燃物连续性好,草本着火且形成高强度地表火后,易引发树冠火,属高燃烧性林分, 应加大灌草清除;幼龄林碳储量138.574 t/ hm2 ,不易发生地表火,但枯死枝可引发树冠火,高林分密度有利于树冠 火蔓延,属高燃烧性林分,应注重整枝,兼顾地表可燃物清理;中龄林碳储量163郾884 t/ hm2 ,可能发生地表火,因间 伐修枝而抬高树冠,降低了林冠火发生的可能性,属低燃烧性林分,可计划烧除灌草;近熟林碳储量199.838 t/ hm2 , 可以发生地表火,甚至树冠火,属中燃烧性林分,应重点清理可燃物累积多的区域;成熟林碳储量253.962 t/ hm2 ,地 表存在大量可燃物,可形成高强度地表火,属高燃烧性林分,应计划烧除。      

大兴安岭北部兴安落叶松树干液流规律及影响因子分析

利用Granier 热扩散植物液流技术(TDP),于2012 年5—9 月连续对大兴安岭北部兴安落叶松蒸腾进行测定, 结合同步观测的环境因子,分析兴安落叶松树干液流规律及其与环境因子的关系。结果表明:1) 兴安落叶松蒸腾速率具有明显的昼夜变化规律,晴天和阴天均为单峰曲线,雨天为双峰曲线,且晴天和阴天的蒸腾速率高于雨天。夜间液流通量占整日液流通量的百分比为晴天(5.91%) 雨天(4.88%) 阴天(2.57%),在高温无雨情况下,液 流通量呈现随高温无雨日数的增加而逐渐降低的趋势。2) 6—8 月兴安落叶松蒸腾量占观测期总耗水量的80%, 液流速率日峰值较高,其中7 月最高达23.6 cm3 / (cm2·h),5 月次之,9 月最低为2.03 cm3 / (cm2·h)。3) 边材液流速率与环境因子存在良好的相关性,多元回归模型决定系数为0郾79;影响兴安落叶松树干液流的主要影响因子为蒸汽压亏缺和光合有效辐射。4) 生长季内兴安落叶松林蒸腾耗水量为566郾49 t/ hm2 ,即56郾65 mm,占同期降雨量 的12%。      

火干扰对兴安落叶松林土壤轻组有机碳的影响

该研究基于土壤轻组有机碳在土壤碳循环中的重要作用,以大兴安岭林区兴安落叶松林土壤为研究对象,分析了火干扰后不同年份高强度火烧对土壤轻组有机碳的影响。用比重分离法对兴安落叶松林火干扰后3年（2008年）、火干扰5年（2006年）和火干扰后9年（2002年）样地及各对照样地的土壤样品进行测定。结果表明：不同年限火干扰后土壤轻组有机碳存在显著差异（P〈0．05）：火干扰后3年土壤轻组有机碳增加11．99％,而火干扰后5年土壤轻组有机碳含量减少了8．77％,火干扰后9年土壤轻组有机碳含量减少了6．27％,减少程度随着时间的推移有所下降。研究结果表明,土壤轻组有机碳与土壤含水率并无显著性关系;火干扰后3年和5年样地轻组有机碳与pH值呈显著性负相关,火干扰后轻组有机碳与土壤温度具有显著性负相关（P〈0．05）。火干扰后短期内土壤轻组有机碳表现出更加明显的季节动态性。该研究为进一步了解火干扰对北方森林土壤碳循环、碳平衡的影响机理以及火干扰后森林生态系统的碳效应提供基础数据。     

A study on the geographic variation and selection of the best provenance ofLarix olgensis

On the basis of the results from the geographic provenance test of nine years oldlarix olgensis in Liangshui Natural Reserve of our university, a study on the geographic varition and the primary selection of the best provenance ofLarix olgensis was carried out. The main results are as follows: I.The different provenances ofLarix olgensis have rich and wide genetic variation, and exist a linear correlation with latitude and longitude in collection area. General trends are enumerated below: Provenances at lower latitude and more west longitude have lighter thousand seed weight, short growth period, higher increment, wide branches, rich leaves and crown as well as worst adaptabillity. It is a dual-way variation along with two directions of latitude and longitude, and also embodies a change gradually in climate condition from south to north. The temperatures in seed production site, especially the mean temperature in January and ≥10 °C accumulated temperature, are important factors that produce geographic variation forlarix olgensis. 2. The variation of different provenances in periodic biological phenomena and growth rhythm trends are that: 1 both of the provenances from Changbai Mt. (III) and Dashitou(IV) at low latitude belong to the centralized growth type, and have shout growth period, the difference between these two provenances is that the provenance from Changbai Mt. grows well in all time, Dashitou provennce is well only in later period; 2 the provenance from Baidao Mt. (II) at middle latitude belongs to even growth type and has longer grpwth period, this provenance has higher increment in early and later periods relatively; 3 Xiaobeihu provenance at high latitude is a growth type among II. III and IV provenances and has a general growth period, the provenance grows better in middle time and worse in later time. 3. The best provenance in Liangshui Natural Reserve and its meighbourhood is Dashitou Procenance, which growth in height, diameter and volume has exceeded 16. 28%, 46. 27%, 30. 58%, 78. 20, 82. 00% as well as 392. 00% by comparison with the mean value of the contrast and the worst provenance respectively, The result from the height growth of three, five, seven and nine years oldLarix olgensis by using the method of order correlation analysis demonstrates that it is possible to make early selection of the provenance. Meanwhile, data from juvenile and mature oflarix olgensis plantation also prove the reliability of the early selection. 4. The provenance heritabilities of nine years oldlarix olgensis in Liangshui Natural Reserve are follows: The heritability of the height growth (h²) is 0.79; The heritability of the diameter breast height (h²) is 0.791; The geretic gain is 24.5% and 40.36% respectively.     

不同营林措施对日本落叶松生物量的影响

通过测量集约经营和一般经营的日本落叶松标准木的地上和地下部分的生物量,并据此分析测量两种不同经营措施的全体生物量,显示出集约经营和一般经营的日本落叶松造林差异很大,集约经营的措施可以促进日本落叶松各个器官迅速生长,单株及全林产量大幅度提高,是提高林木生产率的有效途径。     

长白落叶松苗最佳密度的小气候研究(Ⅰ)——长白落叶松苗群体的太阳辐射分布状况

本文总结了对长白落叶松苗期不同密度的小气候环境的定量测定数据、生物生长量的研究,得出长白落叶松苗最佳密度为600～700株/m~2时群体叶面积指数为2.2,光能利用率为0.26～0.30,太阳透过系数为0.5左右。并建议:将合格苗分为三级,按级加大差价,提高培育伏苗积极性。     

Larix gmelini tannin-based adhesive for plywood

Larix tannin-phenol-formaldehyde (TPF) adhesive, having 60% by weight of phenol being replaced, was evaluated for its utilization in plywood. The kinetic characteristic of the TPF resin was investigated through differential scanning calorimetry (DSC) and the results obtained from the DSC scans show that the resin has a little bit different thermochemical behavior from that of phenol-formaldehyde (PF) resin. Two kinds of plywood panels were produced using the TPF adhesive in laboratory. The desired test results met the Chinese GB 9846-88 and ZB B70006-88, respectively, and the long assembly time of TPF resin in preparing plywood can be improved by mixing with the filler.All the properties of plywoods bonded with the TPF adhesive were compared with those obtained with synthetic PF adhesive.