Analysis of three types of triterpenoids in tetraploid white birches(Betula platyphylla Suk.) and selection of plus trees

Betulin, oleanolic acid, and betulinic acid are naturally occurring pentacyclic triterpenoids that have significant medicinal value. Considerable amounts of these triterpenoids are available in the outer bark of white birch. In this study, we used ultrasound-assisted extraction （UAE） to extract triterpenoids from birch bark rapidly and with high efficiency. Using high performance liquid chro- matography （HPLC）, three types of triterpenoids were separated and detected. We examined the differences among triterpenoids extracted from diploid versus tetra- ploid white birch. Then, we used factor analysis to screen out tetraploid white birches with comprehensively excel- lent performance. The results indicate that the optimum conditions for extraction include the use of ethanol as an extraction solvent, a solid-to-liquid ratio of 0.1 g/10 ml, ultrasonic power set at 100 W, a temperature of 60 ℃ and an extraction time of 15 min. A reversed-phase C18 col- umn （4.6 mm × 250 mm × 5 μm） with a column tem- perature of 30 ℃ and the mobile phase composed of A （acetonitrile） and B （0.1% aqueous phosphoric acid, v/v） at a flow rate of 0.5 ml/min were used, and the detection wavelength was 195 nm. No significant difference wasobserved between diploid and tetraploid white birch in terms of the content of three types of triterpenoids （at a confidence level of 0.05）. As triterpenoid content, height, and DBH （diameter at breast height） are strongly interre- lated, we used factor analysis to evaluate all individuals, and we screened out six plus trees with excellent com- prehensive characters.

A New Caffeoylquiniclactone, Neochlorgeniclatone from the Leaves of Betula platyphylla Suk.

A new caffeoylquiniclactone, named neochlorgeniclatone, was isolated from the leaves of Betula platyphylla Suk. The Structure was established by spectroscopic data.

A New Monoterpene Glucoside from the Leaves of Betula platyphylla Suk.

A new monoterpene glucoside. (2E,67.)-2.6-dimethyl-8-beta -D-glucosyloxy-2,6-octadienoic acid, was isolated from the leaves of Betula platyphylla Suk. The structure was established by spectroscopic data.

Comparison, Selection and Progeny Test of Natural Populations of White Birch (Betula platyphylla Suk.) in Northern China

[Objectives]This study was conducted to rationally and effectively use natural genetic resources of white birch(Betula platyphylla Suk.),and improve the scientific and technological content of improved varieties.[Methods]With the progeny of the white birch populations naturally distributed in northern China as objects,based on genetic effect analysis and comprehensive evaluation,the genetic variation,heritability and genetic gain of the growth characters in the progeny forest were systematically analyzed,by which populations or individuals with good growth vigor and strong stress resistance and adaptability were finally selected.[Results]There were extremely significant differences in the growth characters between the natural populations of white birch in northern China.The variation was the smallest in tree height,followed by crown width,and largest in DBH,and the average coefficients of variation were 20.56%,32.25%and 33.00%,respectively.The differences in characters between progeny of the same population were also extremely significant.The growth characters of white birch were more controlled by genes,and the genetic gains were larger.The heritability of tree height,DBH and crown width was 0.971,0.816 and 0.576,respectively,and the genetic gains were 15.97%,21.54%and 13.87%,respectively.[Conclusions]With the growth characters as the main evaluation indexes,taking various influencing factors into account,the Shanxi[SX]population,Hebei[HB]population and Liaoning[LN]population were selected to be excellent populations,and LN305,SX516 and HB403 were excellent individuals,which are advised to be widely used in multi-generation genetic improvement breeding.

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.

冀西北山地森林不同生境下白桦分枝结构特征

从不同生境和树干胸径的角度研究分枝格局,以揭示树木的结构复杂性程度与生长策略差异,为冀西北山地森林林业管理提供理论依据。以冀西北地区白桦纯林和3个典型混交林为研究对象,采用线性回归法和非参数Kruskal-Wallis检验法,分析胸径和生境对白桦分枝格局的影响。结果表明:①树干胸径对白桦分枝长度、基径和枝生物量的影响显著线性增长(p<0.05),且影响程度随分枝逐级减小(对分枝长度逐级影响为0.504>0.125>0.063>0.034>0.033;基径为0.037>0.014>0.011>0.006>0.005;生物量为0.414>0.025>0.007>0.003>0.002);②不同生境间的各级枝长、枝径和枝生物量都满足:混交林Ⅰ(白桦-落叶松)>混交林Ⅲ(白桦-杏树-杨树-樟子松)>白桦纯林>混交林Ⅱ(白桦-云杉);③白桦落叶松混交林的枝长、基径、生物量和分枝密度均优于其他林型,以最大限度获取空间资源,白桦落叶松混交林是最适合冀西北白桦生长的生境。

Expression profiling of the BpIAA gene family and the determination of IAA levels in Betula platyphylla tetraploids

Betula platyphylla Sukaczev tetraploids have significantly larger leaf, fruit and stoma (gigantic phenotype) than diploids of the same species;however, the mechanism underlying this difference remains unclear. Tetraploid B. platyphylla transcriptome data have indicated that the expression of genes related to indole-3-acetic acid (IAA) biosynthesis and signal transduction was altered after genome duplication. IAA exerts pleiotropic effects on growth and development by inducing the expression of Aux/IAA. We identified 20 Aux/IAA genes (BpIAA1– BpIAA20) in B. platyphylla distributed across 10 chromosomes. Multiple alignment and motif analyses revealed that nine BpIAA proteins shared all four conserved domains. Phylogenetic analysis indicated that Aux/IAA families were divided into four subfamilies and that there were two pairs of BpIAA sister genes. The BpIAAs were differentially expressed in diploids and tetraploids. Moreover, the expression levels of the nine BpIAA genes were specifically up-regulated in tetraploids from June to September compared with May (except August 5th) in tetraploids, while they were down-regulated in diploids. IAA levels were more than twofold higher in tetraploids than diploids during the vegetative season. These results indicate that genome duplication of B. platyphylla caused the up-regulated of genes involved in IAA synthesis, and the increased concentration of IAA may induce the constitutive expression of 20 BpIAA genes. Therefore, the significant changes in the expression patterns of the BpIAAs contributed to the gigantic phenotype of tetraploids to some extent. Our research sheds light on the phenotypic variations observed in B. platyphylla tetraploids.

桦褐孔菌内生真菌的组成研究

为探求桦褐孔菌腐朽木不同腐朽区域内生真菌组成,2021年7月,以采自黑龙江省漠河市的桦褐孔菌腐朽木为研究对象,根据腐朽程度不同将腐朽木横截面从内向外依次划分为腐朽区(木材质地结构发生变化,木质素已基本被降解)、变色区(木质部细胞的细胞壁初步降解,颜色变深)、健康区和菌核区。通过真菌培养技术和高通量测序技术研究桦褐孔菌腐朽木内真菌组成。研究结果显示:桦褐孔菌在木材中扩展严重影响了白桦木不同区域内生真菌的种类组成与物种丰富度。在PDA培养基上从白桦树桦褐孔菌腐朽木不同区域分离出的内生真菌组成有较大差别,腐朽区分离到的内生真菌较多,菌核区域分离到种类最少;高通量测序分析结果表明,健康区的物种丰富度(Chaol)和物种数目(Observed species)指数都明显高于其他区域,说明健康区的物种丰富度较高。变色区内生真菌数量明显减少,腐朽区的内生真菌数量比变色区略有增加,菌核区真菌种类最少。

应用非线性混合模型建立白桦枝长与枝径关系

为了探究枝条生长的动态变化规律,以张家口永定河上游地区为研究区,在研究区设置4个100 m×100 m的固定样地,每个样地采集生长良好的白桦样木4株,共计采集16株天然白桦3 576个枝条数据。在白桦枝长的广义非线性模型的基础上构建样木效应混合模型、枝级效应混合模型和样木枝级嵌套混合模型,采用赤池信息准则(BIC)、贝叶斯信息准则(AIC)、对数似然值(LL)和似然比检验(LRT)等指标比较各模型的拟合效果。结果表明:样木和分枝等级两水平混合效应模型明显优于广义基础模型、样木效应模型和枝级效应模型;当b0、b2、b3作为样木随机参数,b1、b3作为分枝等级随机参数时,两水平混合模型拟合最优,决定系数(R2)和均方根误差分别为0.870 4、11.461 3。因此,考虑样木和分枝等级嵌套两层次的混合模型预测精度均高于广义非线性模型、样木随机效应模型和分枝等级随机效应模型,更好地模拟冀西北白桦的枝长与枝径关系。

亚精胺对盐胁迫下白桦种子萌发与幼苗生理特性的影响

试验设5个处理,研究了不同浓度的亚精胺对盐胁迫下白桦种子萌发和幼苗生理特性的影响规律。结果表明,盐胁迫降低了白桦种子的发芽率、发芽势、发芽指数和相对发芽率,提高了白桦幼苗SOD、POD、CAT、APX活性和可溶性蛋白、可溶性糖、游离脯氨酸、淀粉、叶绿素含量。外源喷施亚精胺有利于提高盐胁迫下白桦种子的发芽率、发芽势、发芽指数和相对发芽率,提高白桦幼苗的SOD、POD、CAT、APX活性和可溶性蛋白、可溶性糖、游离脯氨酸、光合色素含量,降低淀粉含量。综合分析认为,0.8 mmol/L的亚精胺是促进盐胁迫下白桦种子萌发和缓解盐胁迫对其幼苗危害的适宜浓度。

间伐和修枝对白桦天然林林木生长的影响

1998年 ,对林龄为 2 0～ 30a的白桦天然林进行了不同强度的修枝和间伐处理 ,并于 2 0 0 3年春对林分生长状况进行了复查 ,结果表明 :不同强度的间伐和修枝处理对白桦天然林林木胸径生长和冠幅具有显著影响。强度修枝 (2 /3树高 )后 ,林木的胸径生长比弱度修枝降低 8%～ 10 %。中度间伐和强度间伐对保留木胸径生长和冠幅影响较为接近 ,但显著高于弱度间伐。树干解析结果表明 :间伐后 ,林分的材积生长量以中度间伐为最大 (6 .99m3 ·hm-2 ·a-1) ,强度间伐最小 (4.6 1m3 ·hm-2 ·a-1)。 5a的研究结果表明 ,林龄 2 0～ 30a的白桦天然林最适林分密度为 110 0株·hm-2 ,修枝强度不应超过 1/2树高。

指数施肥对白桦容器苗生物量及形态特征的影响

采用常规施肥、指数施肥、1/2指数施肥、2倍指数施肥以及不施肥(对照)5种不同施氮肥处理,研究其对白桦1年生播种苗生物量动态变化及苗木形态的影响。研究结果表明:(1)苗木达到生长高峰期时,生物量净增速率顺序为:2倍指数施肥>指数施肥>1/2倍指数施肥>常规施肥>对照。(2)生长结束后,2倍指数施肥处理苗木年单株生物量为13.32 g,显著高于其他处理。(3)在苗木生长高峰期(施肥后第10周)测定苗木叶面积,指数施肥和2倍指数施肥处理对苗木叶面积增加效果最为明显,达到53.36、53.39 cm2。(4)在苗木生长结束后,2倍指数施肥处理苗木最高为98.89 cm;而指数施肥处理苗木地茎最大,达到7.53 mm。指数施肥处理为最佳施肥方式,有效促进了白桦播种苗生长,改善了苗木形态结构。

白桦种源区划及优良种源的初步选择

以 4个试验点 7年生白桦种源试验林的树高、胸 (地 )径、保存率 ,采用方差分析及多点种源试验联合分析方法 ,进行差异显著性分析 ,结果表明 :各试验点不同种源间生长性状、保存率差异显著 ,种源与立地的交互作用达显著水平。用Tai法进行种源稳定性分析 ,得出栾川、黑河、帽儿山种源为稳定型种源。利用各种源的生长性状、保存率与各种源的地理气候因子做聚类分析 ,进行种源区划 ,初步划分为 10个种源区。综合各种源的生长量和适应性 ,初步为

硝普钠(SNP)和茉莉酸甲酯(MeJA)诱导的白桦Ty1-copia类逆转座子的克隆及分析

利用Tvl—copia类逆转座子逆转录酶（RT）的保守区域设计引物，优化了扩增条件后利用RT—PCR从白桦愈伤组织中得到了1条逆转录酶序列。利用硝普钠（SNP）和茉莉酸甲酯（MeJA）诱导后分别扩增克隆了11条和9条逆转录酶序列。这2l条逆转录酶序列（命名Bprtl-21）变化范围为205—290bp，一致性为71．93％，异质性为1．1％。50．9％，翻译成氨基酸的异质性为0～57．1％。经SNP和MeJA处理的样品中，获得的逆转录酶序列基本是分别聚类．初步证明不同的Tvl-copia类逆转座子能够分别响应不同的信号而被转录激活。分析所获得的21逆转录酶序列和苹果中19务逆转录转座子序列（DQ410748-DQ410766）进化关系发现．逆转录酶基本各自聚类。但是Bprt9、Bprtll和OQ4m750进化关系比较接近，Bprt15、Bprt19、DQ410751和DQ410753聚为一类，证明逆转座子存在水平传递。

2年生白桦种源的地理变异

在“八五”期间对白桦所做全分布区种源试验的基础上 ,又做了一次局部分布区的种源试验。试验选取来自 7个省份的 16个种源 ,在 3个试验点定植。对 16个种源的 2年生幼树高进行方差分析 ,结果表明 ,各种源间的差异极显著 ;利用幼树高与种源的地理因子 (经、纬度 )、气候因子 (温度、积温、降水、湿度、日照、无霜期 )作相关分析 ,研究白桦种源的地理变异 ,发现幼树高与纬度呈负相关 ,与经度呈正相关 ,温度与无霜期是影响地理变异的主要气候因子。初步判断 ,白桦的地理变异符合经纬向双重渐变的模式 ,反映了冷—暖的气候生态模式 。

白桦组培再生系统的研究(Ⅰ)

建立白桦（Ｂｅｔｕｌａｐｌａｔｙｐｈｙｌａｓｕｋｓ）组织培养再生系统，为白桦良种选育、定向培育及遗传转化等方面的研究，提供基础手段和理论依据。采用ＷＰＭ、ＭＳ、ＩＳ三种基本培养基，通过休眠芽获得无菌苗后，再选取无菌苗的不同部位作外植体，分别诱导、分化、生根形成再生植株。

白桦多点种源试验联合分析

调查了４个试验点５年生白桦种源试验林的树高、地径、保存率，采用方差分析及多点种源试验联合分析方法。进行差异显著性分析。结果表明：各试验点不同种源间生长量、保存率等性状差异明显，种源与立地的交互作用尚未达到显著水平。利用各种源的生长量、保存率等性状与各种源的地理气候因子进行相关分析,同时以树高、地径、经纬度为变量进行回归分析，研究种源的地理变异规律。由于各种源的适应性不同，造成各试验点的种源地理变异规律不同。利用聚类分析进行种源区划、初步化分为１２个种源区。最后综合各种源的生长量和适应性，为４个试验点初步选择出各自的最佳种源。

白桦组培再生系统的研究(Ⅲ)——组培过程中内源激素的变化

为了探讨白桦（ＢｅｔｕｌａｐｌａｔｙｐｈｙｌａＳｕｋｓ）组织培养的繁殖机理，选取白桦组织培养过程中的不同材料，采用间接酶联免疫吸附测定法，研究了不同发育阶段、部位及无性系的植物内源激素含量的变化，以及加入不同的外源激素对内源激素的影响，探讨了芽、根的分化与内、外源激素的关系。结果表明：（１）ＩＡＡ是愈伤组织生长的重要内部因子；（２）ＧＡ和ＩＡＡ共同作用促进愈伤组织的生长；（３）不同无性系的ＩＡＡ含量不同，从壮苗培养的增殖倍数来看，ＩＡＡ含量高的无性系具有较高的增殖速度；（４）ＩＰＡ／ＩＡＡ的比值大有利于诱导芽的分化；（５）加入不同的外源激素对内源激素的影响各不相同，其中对ＩＡＡ的影响最大。激素ＢＡ和ＮＡＡ协同作用的效果远远大于其中一种激素的使用效果。

白桦组培再生系统的研究(Ⅱ)——影响因素及培养程序

在“白桦（Ｂｅｔｕｌａｐｌａｔｙｐｈｙｌａｓｕｋｓ）组培再生系统的研究（Ⅰ）”的基础上，以展叶顶芽、休眠腋芽和种子为最初外植体，通过初始培养获得无菌苗后，选取无菌苗的不同部位作外植体，如：茎节、嫩枝、愈伤组织等，经过诱导培养、分化培养及生根培养，形成再生植株。研究了培养基、激素种类及浓度、无性系、外植体类型、蔗糖浓度对诱导及生根的影响，提出白桦组培的最佳条件及程序。最佳无性系的一个外植体，经三次继代培养增殖达３０００株，最佳培养基上的生根率达９５％以上，Ⅰ、Ⅱ级苗的移栽成活率达９０％。

白桦苗期种源试验的研究

对白桦16个种源的1年生苗高、地径进行方差分析．用各种源的苗高、地径与地理、气候因子做相关分析、结果表明：各种源间的苗高、地径差异极显著．苗高、地径与各种源的地理纬度呈负相关．与经度呈正相关。用16个种源的苗高、地径聚类分析．结合各种源的地理、气候因素。可将16个白桦种源区划为5个种源区。即六盘山及祁连山种源区、辽东及长白山种源区、小兴安岭及完达山种源区、大兴安岭种源区和新疆北部种源区，根据白桦苗期的生长表现。初步选择出最佳种源为汪清、凉水种源。