Effects of priming treatments on germination and biochemical characteristics of Pinus bungeana seeds

This experiment was conducted to evaluate the effect of seed priming on the germination and physiology of Pinus bungeana seeds.Seeds were treated by hydropriming with distilled water,halopriming with potassium nitrate (KNO 3) at 0.3,0.6,1.2 MPa respectively (untreated dry seeds were taken as control).Properties of seed germination and physiology were determined and the effect of hydro-and halopriming on germination and physiology of P.bungeana seeds were investigated.The results showed that,compared with control,each priming treatment had increased the germination percentage (GP) and germination index (GI),shortened the mean germination time (MGT) and the time required for 50% of the seeds to germinate (G 50).Primed P.bungeana seeds significantly decreased the relative conductivity and the amount of malondialdehyde (MDA).Of all the treatments applied to seeds of P.bungeana,halopriming at 0.3 MPa KNO 3 produced the highest GP (65.0%) and the shortest MGT (18.8 d) and G 50 (18.2 d).     

水曲柳、胡桃楸等天然次生林生长情况调查

通过标准地调查,对现有天然次生林水曲柳、胡桃楸和黄菠萝幼龄林林分特征、优良单株径级分布、生长过程进行研究,指出相应的抚育技术措施,为小兴安岭天然次生林中水曲柳、胡桃楸和黄菠萝等珍贵阔叶树种单株定向培育提供科学依据。     

水曲柳播种育苗技术

通过对水曲柳种子采集、催芽处理、播种育苗、田间管理、移栽等试验,提供了一套水曲柳播种育苗技术,旨在培育良种壮苗,增加阔叶树造林比重。     

不同间伐强度对水曲柳天然次生林生长动态及乔木层结构的影响

以水曲柳天然次生林为研究对象,以培育大径材为目标,采用典型取样法,研究不同强度间伐对水曲柳天然次生林的生长变化及乔木层组成结构的影响.结果表明:不同间伐强度对水曲柳胸径生长及材积生长差异显著,以弱度和强度间伐的天然次生林分中水曲柳中大径级林木较多,以中度间伐胸径生长率最大;不同间伐强度水曲柳天然林中,林木径级分布以强度...     

水曲柳CUC1基因克隆及瞬时表达分析

[目的]本研究克隆了水曲柳(Fraxinus mandshurica?Rupr.)CUC1基因,分析其表达特性,为该基因在水曲柳再生的调控研究中奠定基础.[方法]从水曲柳苗克隆FmCUC1基因,利用生物信息学软件分析Fm-CUC1基因的核苷酸序列及其编码蛋白的氨基酸序列,并构建系统进化树;利用农杆菌介导法将FmCUC1...     

新疆伊犁河岸小叶白蜡复叶构件生物量分配

小叶白蜡(Fraxinus sogdiana Bunge.)为奇数羽状复叶,常由5~13片小叶组成。通过取样测量,分析不同复叶构件生物量的可塑性及其构件生物量之间的关系。结果表明:小叶白蜡全部样本复叶生物量为0.146~1.663g,平均以7片小叶的最大,并显著高于其他复叶,以5片小叶的最小,并显著低于其他复叶;叶轴生物量为0.016~0.179 g,平均以13片小叶的最大并显著高于其他复叶,以5片小叶的最小并显著低于其他复叶;小叶生物量为0.006~0.886 g,平均以7片小叶的最大并显著高于其他复叶。不同复叶构件生物量具有较大的可塑性,其变异系数为22.8%~138%;对生左、右小叶的生物量分配具有对称性,顶小叶和相同叶序小叶生物量分配随小叶数增多依次减小。不同复叶构件生物量之间的关系既有直线函数的同速生长型,又有幂函数的异速生长型,各构件生物量在复叶生长过程中相对增长速度可通过相关方程的参数做具体描述。     

空气污染对银杏和白蜡树上康氏粉蚧种群的影响

研究了在城市空气污染环境中康氏粉蚧（Pseudococcus comstocki) 在银杏树（Gindgo biloba)、白蜡树（Fraxinus chinensis)上种群密度变化，用化学分析方法测定了城市空气中SO2和Pb在树体、虫体、天敌体内的积累量，结果表明：（1）首次确认和发现康氏粉蚧以银杏树为寄主，并造成严重危害。（2）空气污染物SO2、Pb可被树体、虫体和天敌吸收，并在体内积累。（3）在污染严重的市中心，气温升高，空气污染物SO2、Pb增多，促进康氏粉蚧发育，产卵期提前2－3天，产卵量增加。（4）空气污染程度与树体含污量和康氏粉蚧虫口密度呈正相关，污染愈重树体内S和Pb积累量愈高，在高污染区内银杏树韧皮部和叶片含Pb总量比中－轻度污染区增加10．1％－15．3％，含S总量增加13．9％－22．0％，白蜡树分别增加5．7％－11．9％，及4．5％－7．8％。树体含污量愈高，虫口密度也愈大，在重污染区银杏树和白蜡树上口密度为76．8头／枝及43．1头／枝；中－轻度污染区在两种树上为16．4－2．8头／枝及13．7－2．5头／枝。（5）在重污染环境中银杏树体内氨基酸组分发生变化，有13种氨基酸超过清洁对照区，增幅达24．4％－76．19％，可溶性增加6．46％。（6）康氏粉蚧在空气污染严重的环境中大发生，是寄主树种抗虫性下降和营养条件改变，天短种类和数量大量减少，虫体具有较强的抗污染性能综合作用的结果。     

盐胁迫下白蜡根际微域的营养元素状况

为揭示根-土界面微域养分的吸收、累积与亏缺状况,运用X-射线电子探针研究盐胁迫对白蜡根际和根内营养元素相对含量及其分布的影响。结果表明,与对照（0 g/L）相比,低浓度（3 g/L）盐分处理使白蜡根系吸收较多的Ca、Mg、Cl等元素; 而高浓度（9 g/L）处理则使根系吸收Ca、Mg、Cl的能力下降。白蜡根内Na、K、Fe的累积量和根际Na的含量随盐浓度增加均有升高; 其中,过量的Na会破坏白蜡根细胞原生质膜的结构,引起胞内营养大量外泌,造成植物营养缺乏,从而诱发盐害。因此,Na在根际微域的累积是引起白蜡盐害的主要原因。     

Leaf litter selection by detritivore and geophagous earthworms

Summary Litterbag experiments with 10 different kinds of leaf litter showed that detritivore (Lumbricus species) and geophagous (Aporrectodea species) earthworms prefer certain litter types over others, since different numbers of worms were found below the litter after 50–52 days of exposure in a pasture. The detritivores preferred Fraxinus, Tilia, and predecomposed Ulmus and Fagus litter to Fagus litter and paper, while geophages preferred Tilia litter to Alnus and Ulmus litter, so that the two groups of earthworms showed different preferences. The detritivores seemed to be more selective than the geophages. The palatability of the litter was examined in relation to the C: N ratio, the lignin concentration and the initial and final polyphenol concentration. The numbers of detritivores were significantly correlated with the C: N ratio and the final polyphenol concentration, so that selection of litter seems to be related to palatability. The numbers of geophages were not significantly correlated with any of the parameters for palatability. The disappearance of litter after 50–52 days appeared to be due to detritivore activity, since the numbers found below the litter were positively and significantly correlated with the litter disappearance. There was no significant correlation with geophage activity. This indicates that detritivores use litter as food, and therefore influence the composition of the litter layer.     

水曲柳苗木平茬与去顶芽促萌试验

实验证明水曲柳1年生插穗的生根率较高,如果能利用少量有限的超级苗资源获得大量1年生萌条,则可增加插穗来源,实现利用扦插技术大量扩繁优良资源的目的.本试验以水曲柳超级苗的平茬桩(仅留1～2个侧芽)和去顶芽桩(仅摘除项芽)为试材,采用激动素(KT)、2,4-二氯苯氧乙酸(2,4-D)、高锰酸钾(KMnO4)、三十烷醇(TA)和诱芽营养剂进行萌芽促进试验,探索获得大量的1年生萌条的途径.结果表明,对水曲柳1年生苗平茬桩,诱芽营养剂的促萌效果相对较好,其次是1 mg/L的KT和5%的KMnO4;对水曲柳1年生去顶芽桩,诱芽营养剂促萌效果较好,1 mg/L和20 mg/L的2,4-D,5 mg/L的KT、TA和2,4-D,1%和5%的KMnO4也有一定效果;对水曲柳2年生苗平茬桩和去顶芽桩,诱芽营养剂萌芽促进效果较好;对2年生苗平茬桩,0.1 mg/L的KMnO4浸泡48 h的促萌效果也较好.总体来看,诱芽营养剂对水曲柳苗桩萌芽促进的应用潜力最大.