Analysis of EST-SSRs in silver birch(Betula pendula Roth.)

Simple sequence repeats（SSRs） defined as sequence repeat units between 1 and 6 bp occur abundantly in both coding and non-coding regions in eukaryotic genomes and these repeats can affect gene expression. In this study, ESTs（expressed sequence tags） of Betula pendula（silver birch） were analyzed for in silico mining of ESTSSRs, protein annotation, open reading frames（ORFs）,designing primers, and identifying codon repetitions. In B.pendula, the frequency of ESTs containing SSRs was 7.8 %with an average of 1SSR/4. 78 kb of EST sequences. A total of 188 SSRs was identified by using MISA software and dinucleotide SSR motifs（65.9 %） were found to be the most abundant type of repeat motif followed by tri-（27.1 %）,tetra-（4.8 %）, and penta-（2.2 %） motifs. Based on ORF analysis, 175 of 178 sequences were predicted as ORFs and the most frequent SSRs were detected in 50 UTR（58.43 %）,followed by in ORF（31.46 %） and in 30UTR（8.43 %）. 102 of 178 ESTs were annotated as ribosomal protein, transport protein, membrane protein, carrier protein, binding protein,and transferase protein. For a total of 102 SSRs（57.3 %）with significant matches, a set of 102 primers（100 %） with forward and reverse strands was designed by using Primer 3 software. Serine（Ser, 19.6 %） was predominant in putative encoded amino acids and most of amino acids showed nonpolar（35.3 %） nature. Our data provide resources for B.pendula and can be useful for in silico comparative analyses of Betulaceae species, including SSR mining.

Expression of BpPIN is associated with IAA levels and the formation of lobed leaves in Betula pendula ’Dalecartica’

Auxin polar transport genes PIN(PINFORMED)determine the concentration gradient of auxin in plants.To understand the relationship between the development of different tissues in Betula pendula‘Dalecartica’,BpPIN gene expression and indole-3-acetic acid(IAA)content were analyzed using qRT-PCR,ELISA,and GUS staining.Gene expression of BpPIN genes and IAA levels in the leaves,buds,stems,xylem,and roots of B.pendula‘Dalecartica’and B.pendula as a control were measured.BpPIN1,BpPIN5 and BpPIN6 were upregulated during development in both species,suggesting a dominant role in the development of B.pendula‘Dalecartica’leaves.Moreover,BpPIN1 gene expression was positively associated with IAA levels during leaf,vein and petiole development in B.pendula‘Dalecartica’only.The correlation coefficient of the first three leaves was 0.69(P=0.04),while that of the first three petioles was 0.85(P=0.001).In addition,GUS staining of the pro-DR5::GUS transgenic line of cultivar was correlated with the results of BpPIN1 expression.Overall,these findings suggest that BpPIN1 is associated with the formation of lobed leaves in B.pendula‘Dalecartica’.

Identification of SSR loci in Betula luminifera using birch EST data

Expressed sequence tags（ESTs） are generated from single-pass sequencing of randomly picked cDNA clones and can be used for development of simple sequence repeat（SSR） markers or microsatellites.However,EST databases have been developed for only a small number of species.This paper provides a case study of the utility of freely available birch EST resources for the development of markers necessary for the genetic analysis of Betula luminifera.Based on birch EST data,primers for 80 EST-SSR candidate loci were developed and tested in birch.Of these,59 EST-SSR loci yielded single,stable and clear PCR products.We then tested the utility of those 59 markers in B.luminifera.The results showed 28（47.6%） yielded stable and clear PCR products for at least one B.luminifera genotype.In addition,this study describes a rapid and inexpensive alternative for the development of SSRs in species with scarce available sequence data.

Effect of MeJA and Light on the Accumulation of Betulin and Oleanolic Acid in the Saplings of White Birch (<i>Betula platyphylla</i>Suk.)

In this study, we investigated the effect of different types of light and MeJA treatment on the accumulation of betulin and oleanolic acid in various organs of white birch. Our results showed that betulin and oleanolic were accumulated mainly in the stalk skin. The content of both substances in the stalk skin was significantly affected by seasons with a peak accumulation in August. The content of oleanolic and betulin was significantly decreased in the stem skin treated with 4 types of light (red, yellow, blue and green) compared with the plant with normal illumination. In contrast, oleanolic acid in leaves was increased by 13.28 folds when the white birch was treated with green light. Betulin was increased by 1.959 folds in leaves of white birch treated with blue light. The highest content of betulin and oleanolic acid in various organs of birch with appropriate shading treatment (light transmittance: 50%) was increased by 45.09% and 30.50%, respectively, in comparison with those with non-shading treatment. Content of oleanolic acid and betulin can be significantly improved in various parts of birch after treatment with different concentration of MeJA. The study lays the foundation to metabolic regulation of oleanolic acid and betulin in birch.

Pilot study on the effects of elevated air temperature and CO2 on artificially defoliated silver birch saplings

The impacts of elevated temperature and COon young silver birch(Betula pendula Roth) saplings after 0,25, 50 or 75% artificial defoliation were assessed by measuring plant height and dry mass of aboveground compartments and roots and various morphological and physiological variables. Defoliation either increased or decreased plant growth depending on the severity of damage and the climatic treatment. At 21 °C and400 mg LCO, defoliated plants were not able to compensate for the lost foliage, but growth compensation and adaptation to the changed conditions were greater; growth of young defoliated silver birch saplings increased, which led to increased height and a tendency to enhance final aboveground and root biomass and leaf nitrogen and carbon content compared to the nondefoliated controls. Nevertheless, the short-term effect of the different climatic conditions did not result in a significant overgrowth of defoliated plants. A slight increase in temperature and COwere the most acceptable conditions for defoliated plants;however, a 4 °C increase with correspondingly higher COwas more stressful as shown by less growth in height and biomass allocation to leaves, stems and roots. The findings from the pilot experiment are more applicable to young birch trees, but stress on young trees may be reflected in future tree growth.

Growth and chemical composition of silver birch:Comparative study between Lithuania and Romania

The effects of different climatic conditions on growth and chemical composition of Betula pendula in geographically different European regions,Lithuania and Romania,were compared.Birch species in the entire area have a wide natural distribution,but B.pendula is commercially more important in Lithuania than in Romania.Here we evaluated tree ring width,wood density and foliar chemical composition of mature birch trees in two European regions.Trees at the Lithuanian sites had greater radial growth and wood density with no clear changes in foliar chemistry than those at the Romanian sites.Mean wood density was 600-700 kg m^(-3) at Lithuanian and 350-450 kg m^(-3) at Romanian sites.Mean width of wood ring,earlywood and latewood for Lithuanian birch trees were several times higher than the means for Romanian birch trees.We hypothesized that the main differences in birch radial growth and wood density were due to the different climatic conditions in the studied regions.Ca,K and Mg concentrations were significantly higher and Fe and Mn were lower in the birch foliage at the Lithuanian sites compared those at the Romanian sites.Overall assessment of growth showed that silver birch cultivation is more appropriate for colder climate regions and that birch growth may change in the context of a warming climate.

腐胺对枫桦和欧洲白桦嫩枝扦插生根及根茎养分含量的影响

【目的】枫桦和欧洲白桦作为用材林、土壤修复和城市绿化的优良树种,具有重要的经济和生态价值,优树嫩枝扦插是加快枫桦和欧洲白桦良种快速扩繁的重要途径,腐胺作为一类具有高生物活性的含氮碱与插穗生根关系密切,近年来受到诸多学者关注。研究腐胺对2个树种嫩枝扦插生根过程中的根系性状和根茎非结构化碳水化合物含量变化的影响,探讨其对2个树种嫩枝扦插生根作用效果的最佳浓度。【方法】以同家系枫桦和欧洲白桦2年生嫩枝为试验材料,设置不同浓度梯度T1、T2、T3(500、1000、1500 mg·L^(-1))的腐胺溶液浸泡组和对照组(CK1和CK2)处理,测定插穗不定根生根率、生根数、根长、根质量和根茎非结构化碳水化合物含量,通过方差分析、相关性分析和隶属函数分析揭示腐胺对2个树种插穗生根和养分含量的影响。【结果】腐胺对枫桦扦插生根促进效果最适浓度为500 mg·L^(-1),生根率达26.7%,生根数达5.3个,平均根长达9.4 cm;对欧洲白桦的最佳浓度为1000 mg·L^(-1),生根率达42.7%,生根数达6.7个,平均根长达6.5 cm。而对于根茎非结构化碳水化合物含量,1000 mg·L^(-1)浓度腐胺对枫桦根茎非结构化碳水化合物含量提升整体效果最佳,500 mg·L^(-1)浓度腐胺对欧洲白桦根茎非结构化碳水化合物含量的促进效果更好。【结论】腐胺浓度是影响2个树种扦插生根特性的关键因素,与传统处理方法ABT(生根粉)或IBA(吲哚丁酸)相比,腐胺不仅显著促进了2个树种插穗生根率、根长、根质量等性质,还对根茎非结构化碳水化合物含量具有提升作用,但通过隶属函数分析显示,腐胺+ABT(或IBA)整体指标促进效果虽然最优,但较仅使用ABT(或IBA)处理组该优势并不明显。

白桦EST-SSR信息分析与标记的开发

对NCBI(美国国立生物技术信息中心)中2548条欧洲白桦ESTs的序列进行分析,结果表明:其中260条ESTs中含有306个SSRs,为全部ESTs序列的10.2%,SSR频率为12.01%。其中,二核苷酸重复比例为81.37%,三核苷酸重复比例为16.67%,四核苷酸重复比例为1.96%。不同软件设计引物的效率不同,Primer3设计出176对SSR引物,在白桦中扩增成功的引物比例为59.09%,而具有多态性的引物比例仅为25.96%;SSR Primer设计出100对引物,在白桦中扩增成功的引物比例为37%,而具有多态性的引物比例为48.65%。

裂叶桦和欧洲白桦叶片形态特征及相关基因表达特性比较

为了探寻欧洲白桦变种裂叶桦的叶缘分裂机制。以2种桦树为研究对象,在叶片形态特征和解剖特征观测的基础上,进行了顶芽及叶片叶尖、裂片及凹缺等不同组织部位相关基因表达定量分析、内源激素IAA含量测定以及IAA活体标记的GUS染色分析。结果表明,裂叶桦叶片两侧叶缘自叶基到叶尖分裂出由大到小3~4个裂片,叶背面的叶脉呈明显的管状隆起,叶宽、平均二级脉间距、主脉横切面积等分别较欧洲白桦大了21.12%、12.64%、21.46%。BpmiR164s及靶基因的组织表达特性分析结果证明,BpmiR164-2及靶基因BpCUC2与裂片的形成关系密切,是裂叶性状产生的主要调控基因。生长素输出载体BpPINs基因的组织表达特性分析结果证明,6个基因中只有BpPIN2和BpPIN5在裂叶桦的叶尖、裂片及顶芽等组织器官中呈现上调表达。内源激素IAA的活体标记发现,在顶芽、幼叶中IAA的含量较高,而在叶片中,叶尖、叶齿及裂片处是激素的高表达部位,利用液相色谱—质谱联用仪(LC-MS)对2种桦树的上述不同组织部位的生长素测定也证明了激素的上述分布特点。综合上述,裂叶桦裂片产生是激素在叶脉、叶缘的极性运输及相关基因调控的结果。

白桦三倍体制种园中各家系种子活力比较

种子活力能够预测出苗率和幼苗生长潜势,可作为林木种子园母树评价的重要指标。以白桦三倍体制种园中15个三倍体家系及1个二倍体对照为试材,开展家系间种子活力及幼苗生长特性的比较研究。结果表明:种子千粒质量、主要活力指标及活力指数等7个指标在不同家系间的差异均达到极显著水平(sig.<0.01);根据发芽势、发芽指数、活力指数及幼苗健壮率等7个指标,采用模糊数学中隶属函数值的方法,对参试家系进行综合评价,结果是排在二倍体对照家系前的只有3个三倍体家系,初步确定这3个家系的采种母树为改建三倍体制种园的首选母树。

紫雨桦花色素苷含量的时空变化及相关基因的表达特性分析

以3年生紫雨桦无性系为试材,分别测定枝顶、中、下部叶片及不同发育阶段的花色素苷、叶绿素含量,同时采用qRT-PCR技术分析BpCHS与BpDFR的时空表达特性。结果表明:紫雨桦枝顶、中部及下部叶片的花色素苷及叶绿素含量差异显著,不同生长阶段2种色素的含量也达到显著水平;紫雨桦5—8月枝顶1~2叶片均为暗紫色或紫色,枝顶花色素苷含量在各生长阶段均显著高于中、下部叶片,枝顶、中部及下部叶片中的花色素苷与叶绿素含量时序变化呈现相反趋势。线性回归分析显示,2种色素的含量呈极显著线性负相关;对紫雨桦的3条BpCHS与4条BpDFR基因时空表达特性分析显示,在叶色呈现暗紫色或紫色的叶片中BpCHS2与BpCHS3基因表达量最高,在紫雨桦枝顶、中部及下部叶片颜色变化明显阶段,参试的4条BpDFR基因呈现显著的上调或下调,因此紫雨桦的叶色与BpCHS2、BpCHS3及BpDFR密切相关。

不同碳源对白桦愈伤组织生长和三萜积累的影响

在一个继代周期中,培养基中添加10～50 g·L^(-1)的蔗糖、葡萄糖和果糖后,白桦愈伤组织的鲜重均上升,浓度为20～30 g·L^(-1)的三种糖,其鲜重积累量均较高。培养基中添加不同浓度葡萄糖和果糖的白桦愈伤组织中三萜物质含量先上升后下降,而添加蔗糖的则呈直线上升。其中,葡萄糖、果糖和蔗糖浓度为30 g·L^(-1)的三萜类物质积累量最高。

欧洲垂枝桦的组织培养和植株再生

以引种的欧洲垂枝桦1 a生的腋芽茎段为外植体,以WPM为基本培养基进行离体培养,以期获得最适培养基及激素种类和浓度组合,结果表明:欧洲垂枝桦腋芽离体培养最佳培养基为WPM+2.0 mg.L-16-BA;最佳生根培养基为WPM+NAA 0.5 mg.L-1+IBA 0.2 mg.L-1。

白桦RAPD遗传连锁图谱的构建

以80个来自欧洲白桦(Betula pendula Roth)×中国白桦(Betula platyphylla Suk)的F1个体为作图群体。利用2个亲本和10个F1个体对1,200个10bp的随机寡核苷酸引物进行筛选,确定了208个多态性引物。利用RAPD标记,按照拟测交的作图策略,分别构建了欧洲白桦和中国白桦的分子标记连锁图谱。对2个亲本和80个F1代作图群体进行随机扩增,共获得了364个多态性位点。χ2检验结果表明有307个位点符合1∶1分离的拟测交分离,26个位点符合3∶1分离,31个位点属偏分离位点。拟测交位点中有145个位点来自欧洲白桦,有162个位点来自中国白桦。利用2点连锁分析,欧洲白桦中的145个连锁标记构成了14个不同的连锁群(4个以上标记),6个三连体和6个连锁对,37个为非连锁位点,连锁标记覆盖的总图距为955.6cM(centimorgan),平均图距14.9cM。而来自中国白桦的162个标记构成了15个连锁群(4个以上标记),4个三连体和6个连锁对,21个为非连锁位点,连锁标记覆盖的总图距为1,545.8cM(centimorgan),平均图距15.2cM。该图谱的建立为进一步将两个图谱整合为一个高密度图谱及重要基因的定位奠定了基础。

赛黑桦的构造特征和物理力学性质

赛黑桦（Betula schmidtii）,又称辽东桦,散孔材;木质厚重、坚硬,传统上用来制作车轴、木锤、擀面杖、算盘珠等（戚继忠等,2009;Akcehob et al.,2006）,主要生长在我国东北东部与朝鲜接壤地区,与该地区相邻的朝鲜南部和俄罗斯南部海滨一带（锡霍特山脉南端）亦有分布,成年立木高约20m,树干直径约70cm,寿命约300-350年（Nechaeva,1972;RedBookoftheUSSR，1984；Korkishko，1992）。

欧洲白桦优良无性系试管苗生根与移栽的研究

欧洲白桦各无性系试管苗诱导生根的能力从易到难依次为:2/86、1/86、4N、G 1;以1/2M S为基本培养基。对于无性系4N,单独使用NAA(0.3 m g.L-1)比单独使用IBA和同时使用NAA与IBA更有利于试管苗不定根诱导;0.1 m g.L-1NAA与0.1 m g.L-1IBA配合使用,诱导无性系1/86、2/86的试管苗生根,效果最佳。白桦试管苗木质化程度越高,其生根率有下降的趋势。试管苗移栽采用腐殖土∶细沙∶园土(1∶1∶1)或腐殖土∶园土(2∶1)作栽培基质效果较好。试管苗在生根培养基上培养的天数以及生根试管苗的生长状况对移栽成活率影响明显,试管苗不定根伸长最快的时期,移栽成活率最高。

东北林区天然白桦相容性生物量模型

基于东北林区天然白桦实测生物量数据,通过2种方案(以总生物量为基础分级控制和以总生物量为基础直接控制)建立天然白桦一元和二元相容性生物量模型,模型参数估计采用非线性度量误差联立方程组估计方法,并采用加权回归的方法进行异方差的消除。结果表明:2种方案所建立的天然白桦一元、二元相容性生物量模型的确定系数R2=0.800～0.988,模拟效率(EF)=0.80～0.97;2种方案所建立的相容性生物量模型的预测精度大多数在80%以上,树枝和树叶生物量模型的预测精度较差,但也在69%以上;所建立的相容性生物量模型中,总生物量和树干生物量模型效果较好,树根、树叶和树枝生物量模型效果较差。总的来说,2种方案所建立的相容性生物量模型都具有一定的精度,都能对天然白桦生物量进行很好的预估,以总生物量为基础直接控制方案所建立的一元和二元相容性生物量模型好于以总生物量为基础分级控制方案所建立的一元和二元相容性生物量模型,所以在进行天然白桦生物量预估时,建议采用以总生物量为基础直接控制所建立的相容性生物量模型。

热激处理对白桦幼苗温度适应的影响

以白桦为研究对象 ,人为模拟高温 ,以质膜相对透性和丙二醛含量为主要测定指标 ,比较了不同高温和不同处理时间对 1年生白桦幼苗的伤害程度以及高温预处理对白桦幼苗温度适应的影响 .结果表明 ,膜相对透性及丙二醛含量在 37℃和 4 2℃热激处理的 2 4h期间出现升、降、升的变化趋势 ,但 37℃ 2～ 4h处理为白桦热激反应的理想条件 .37℃

转基因白桦的花粉活力及外源基因的遗传表达分析

采用荧光素二乙酸酯(FDA)染色比较分析转基因白桦花粉的活力的结果表明,转基因白桦的花粉活力均低于非转基因白桦。应用多重PCR和Northern杂交技术分析表明,转基因白桦花粉中有外源基因整合和转录表达。检测转基因白桦花粉中gus报告基因的活性,显示gus报告基因在花粉表达。

基于RAPD标记的白桦遗传连锁群分析

Based on the genetic inheritance and segregation of random amplified polymorphism DNA(RAPDs) markers,the analysis of linkage groups for birch was performed by using a pseudo-testcross strategy.A segregating population comprising of 79 progenies from the cross between Betula pendula and B.platyphylla was obtained.A set of 1 000 random oligonucleotide primers were screened,and 178 primers were selected to generate RAPD markers within a sample of 79 F\-1 progenies.A total of 296 segregating sites was identified.Among them,273 sites belonged to 1∶1 segregating site,and 36 sites were found distorted from the 1∶1 ratio.The 273 sites segregating 1∶1(testcross configuration) were used to construct parent-specific linkage group,among which 137 sites were found for B.pendula and 136 sites for B.platyphylla.The resulting linkage maps consisted of 117 marker sites in 12 groups(four or more sites per group),2 triples and 3 pairs for B.pendula,which covered the map distance about 1 533.3 cM(Kosambi units),and the average map distance between adjacent markers was 16.4 cM.In the B.platyphylla,162 linked marker sites were integrated into 12 groups(four or more sites per group),2 triples and 4 pairs,which covered the map distance about 1 847.8 cM,and the average map distance between adjacent markers was 19.2 cM.The calculated genome coverage rate of B.pendula and B.platyphylla were respectively 68.5% and 68.9%.Further study is required to integrate the two maps to one density map and to locate important genes on the maps.