云南红豆杉天然种群遗传多样性研究

采用垂直板式聚丙烯酰胺凝胶电泳，检测了云南红豆杉（Taxus yunnanensis)雌配子体的5种等位酶，并以10个基因位点编码的5个酶系统，分析了滇西北3个云南红豆杉天然种植的遗传多样性与遗传分化。结果表明，群体的多态位点比例是0．77；群体的平均杂合性观察值是0．302；预期值为0．3320；每个基因位点发现的等位基因数是2．05，有效等位基因平均数是1．466。对10个基因位点的基因多样性测定表明，种群间的分化占14．66％。总的基因多样性约85％产生于种群内。群体间的平均遗传距离是0．118。     

南岭山地南方红豆杉天然林与人工干扰群体的遗传变异分析

【目的】南岭山地的南方红豆杉资源丰富,分布集中,群体类型多样,是研究不同干扰群体遗传变异的理想材料。本研究对南岭山地南方红豆杉群体的遗传变异水平进行探究,比较其天然林群体和人工干扰群体的遗传差异,揭示人类活动对植物群体遗传变异的影响,为制定南岭山地南方红豆杉遗传保护策略提供科学依据。【方法】本研究基于叶绿体基因组标记方法,利用4个非编码区序列分析南岭山地南方红豆杉的遗传变异模式,比较不同干扰程度群体(天然林和人工干扰林)的遗传变异特征及其遗传分化。【结果】在种的水平,8个南方红豆杉群体中共检测出4个单倍型,单倍型多样性(Hd)为0.552,核苷酸多样性(Pi)为0.000 23。基因遗传分化系数分别为NST=0.190,GST=0.158,且NST (0.190)大于GST (0.158)(P 0.01)。不同干扰程度群体遗传变异检测结果表明,天然林群体中检测到4个单倍型,包含2个私有单倍型,单倍型多样性(Hd)为0.603,核苷酸多样性(Pi)为0.000 27;而人工干扰群体仅检测到2个共享单倍型,单倍型多样性(Hd)为0.508,核苷酸多样性(Pi)为0.000 20。【结论】南岭山地的南方红豆杉群体存在明显的谱系地理结构,分子方差分析(AMOVA)结果显示遗传变异主要来自群体内,遗传分化高。天然林群体的遗传多样性高于人工干扰群体,天然林和人工干扰林两组群间存在明显的遗传变异。研究结果可为南岭山地南方红豆杉资源的保护和可持续利用提供参考。     

长阳栓皮栎天然群体遗传多样性的等位酶分析

采用5种等位酶对长阳栓皮栎天然群体的遗传多样性和遗传变异进行了研究。共检测到7个基因位点,15个等位基因,其中5个位点为多态位点;群体多态位点比例P=71.4%,平均等位基因数A=3.2000,平均有效等位基因数AE=1.6090,平均期望杂合度HE=0.3563,观测杂合度HO=0.3625。长阳栓皮栎群体的遗传多样性较高,遗传变异水平较高。     

毛红椿天然群体遗传多样性及取样策略探讨

[目的]研究毛红椿天然群体遗传多样性取样策略,为其种质资源收集、保存和遗传多样性保护等提供参考依据。[方法]利用8对微卫星分子标记进行毛红椿天然群体遗传多样性和空间自相关分析,综合制定其天然群体合理取样策略。[结果]毛红椿天然群体等位基因数平均为7.5个,期望杂合度(H_e)和多态性信息指数(PIC)均值分别为0.643 7和0.636 0,基因分化系数(G_(ST))均值为0.290 7。在遗传多样性取样策略方面,提出了根据毛红椿群体基因分化系数来确定取样群体遗传变异所占总变异比例的运算公式为1-(G_(ST))~(n-1),其中,n为取样群体的数量。当取样群体达到4个时,基本上能包括该树种97.5%的遗传变异;同时确定了目标群体的选择方法,应选择与其它群体间基因分化系数均值较大的4个群体,即贵州册亨(CH)、浙江遂昌(SC)、浙江仙居(XJ)和云南师宗(SZ)。通过构建云南宾川(BC)、云南师宗(SZ)和江西宜丰(YF)群体内取样单株数量与基因多样性和等位基因之间的捕获曲线,确定了群体内取样单株数量应达到15个以上;毛红椿天然群体内300～520 m范围内的单株间存在相似关系,超出此范围个体间差别较大,说明在进行群体内单株取样时,单株间距应大于520 m。[结论]取样群体数量、群体间遗传分化系数、群体内单株数量以及单株间距离等影响了毛红椿取样群体的遗传多样性。毛红椿天然群体遗传多样性取样策略为取样群体4个、每个群体最少取样15个单株,单株间距大于520 m。     

思茅松天然群体的遗传多样性及遗传分化

采用凝胶电泳技术,检测了思茅松(Pinuskesiyavar.Langbinaensis)种子胚乳的9种同工酶。通过对9种酶系统编码的16个酶位点的遗传分析,揭示了思茅松三个天然群体的遗传多样性和遗传分化情况。思茅松天然群体的遗传多样性较高,群体的多态位点比例为0.667;平均每个位点的等位基因数为2.13;期望杂合度和观察杂合度分别为0.288和0.197。群体间的遗传分化程度较低,分化系数仅为0.052,群体间的遗传距离为0.015。表5参15。     

白皮松天然群体遗传多样性的等位酶分析

采用8种等位酶对白皮松4个天然群体的遗传多样性和遗传分化进行了研究.在4个群体中共检测到10个基因位点,15个等位基因,其中6个位点为多态位点;群体总体水平多态位点比率P=60%,平均有效基因数A=1.92,平均期望杂合度He=0.106,种群平均遗传距离为0.006 8.南漳白皮松群落平均等位基因数A=1.9,平均有...     

白皮松天然群体遗传多样性的EST-SSR分析

为探讨白皮松群体间遗传变异规律,使用7对EST-SSR引物对分布区内21个白皮松天然群体的遗传多样性及遗传分化水平进行了研究。结果表明:7对引物在21个白皮松天然群体的663个单株中共检测到14个多态性位点。各群体间有效等位基因数(Ne)、Shannon’s信息指数(I)、观测杂合度(Ho)、期望杂合度(He)、Nei’s期望杂合度(Nei’s)分别为1.156 5 1.601 9、0.133 5 0.492 5、0.138 4 0.397 3、0.0860 0.342 8、0.084 6 0.337 4。白皮松群体间遗传分化系数(Fst)平均为0.215 2,基因流(Nm)值平均为0.911 9,群体间基因交流总体较少,遗传分化较大。白皮松多样性水平在分布区内呈规律性变化,多样性分布的中心区域主要在西部、南部,具有从西向东,从南向北依次减少的趋势。     

青海云杉群体同工酶变异的研究

本文利用聚丙烯酰胺凝胶垂直板电泳技术,研究了青海云杉4个天然群体8个基因位点表达的5种同工酶的变异模式。结果表明,青海云杉具有较高的遗传变异性,多态位点百分率为49.95％,每位点等位基因平均数为2.38,平均期望杂合性为0.212。群体分化水平较低,平均基因分化系数为0.023。群体间遗传距离平均值为0.01224,遗传距离和空间距离间存在正相关性,其间相关系数为0.8409,空间上相距较近的群体在遗传上具有较高的相似性。     

蒙古栎天然群体等位酶遗传多样性研究

以中国蒙古栎全分布区的8个天然群体和辽东栎1个天然群体为研究对象,进行了水平淀粉凝胶电泳技术的同工酶分析,共分析了13种酶系统产生22个位点。结果表明：(1)蒙古栎在种和群体水平的遗传变异水平较低,多态位点百分率P分别为52．38％、28．976％,期望杂合度He分别为0．099、0．085,观测杂合度H0分别为0．092、0．088;(2)蒙古栎群体间遗传分化程度较高,分化度Gst为0．107,遗传多样性中的遗传变异量89．27％存在于群体内;蒙古栎群体水平的基因流Nm比值为2．080。(3)蒙古栎群体间的平均遗传距离D较低,为0．0121,各群体之间的遗传一致度I为0．097-1．00;(4)东灵山辽东栎群体的遗传多样性较低,多态位点百分率P为36.36%,期望杂合度He为0．083,观测杂合度H0为0．070;(5)利用群体间遗传距离进行的UPGMA聚类结果表明,蒙古栎自然分布区的东北部的4个群体和西南部的2个群体分别聚为一亚类,这与其地理分布格局大致吻合,但群体间遗传距离与地理距离无明显的相关性。(6)长期的砍伐和破坏,造成有效群体较小,而且经受繁殖瓶颈效应,是蒙古栎遗传多样性下降的主要原因。     

红松群体内和群体间同工酶变异的研究

本文以四个位点编码的三种酶(EST、MDH和GOT)系统,分析了我国东北林区红松林四个群体同工酶的遗传变异和分化。群体内的同工酶变异,四个位点所有样品杂合性的平均值是0.37,并发现每个位点的等位基因平均值是2.25。群体间的同工酶分化,对四个位点的基因多样性测量表明,群体间分化的明显效果是2％。总基因多样性的98％产生在群体内。所有配对组合,群体间的平均遗传距离是0.025±0.008。     

Genetic diversity and differentiation among populations of the pedunculate oak (Quercus robur) at the eastern margin of its range based on a new set of 95 SNP loci

The aim of this study is to determine the genetic variability and differentiation among populations of pedunculate oak(Quercus robur) at the eastern margin of the species distribution range.We applied new set of 95 geographically informative nuclear SNP(single nucleotide polymorphism) loci developed using Double Digest Restriction Site Associated DNA(ddRAD),a new generation DNA sequencing technology.The study area is located in the basins of the Volga River and its two main tributaries,Kama and Belaya.Despite the strong reduction and fragmentation of pedunculate oak forests over the last several centuries and comparatively small sizes of present stands,a relatively similar genetic diversity of seven populations was observed(on average,allelic diversity v_a=1.472-1.603,observed heterozygosity H_O=0.305-0.358,expected heterozygosity H_E=0.272-0.343).The genetic distances between populations vary between 0.102 and 0.170(on average,d_0=0.128).We have identified the absence of a spatial genetic structure and the existence of genetically peculiar populations in the territory studied.The genetic distances of Gregorius between populations vary between 0.102 and 0.170(on average,d_0=0.128).Genetic differentiation among populations was statistically significant with a mean of the fixation index F_(ST) of 0.075.Populations from the Privolzhye Upplands and from northern parts of the study area make the most contribution to overall inter-population differentiation(d_0=0.137).No significant differences exist among the samples at lowlands along the Volga river(d_0=0.110).It was concluded that the multiplicity and different ages of local populations and the complexity of migration routes of the pedunculate oak from Pleistocene refugia and secondary Holocene shelters can cause this phenomenon.     

Genetic diversity and conservation of two threatened dipterocarps(Dipterocarpaceae) in southeast Vietnam

Two threatened dipterocarp species,Dipterocarpus costatus and Dipterocarpus alatus are well-known endangered species in lowland forests of southeastern Vietnam,primarily from habitat loss and over-exploitation of their wood.To develop conservation strategies for these species,we analyzed 242 samples using nine microsatellite markers to determine the genetic variability within and among five populations of D.alatus and three of D.costatus,representing the natural range of dipterocarps in Southeast Vietnam.Results indicated low levels of genetic variability within populations with an average gene diversity of 0.223 for D.alatus and 0.152 for D.costatus.Results of bottleneck tests indicated a reduction in population size of both species(P>0.05).Genetic differentiation among populations was high(FST=0.347 for D.costatus and 0.274 for D.alatus),indicating limited gene flow(Nm=0.662 for D.costatus and 0.47 for D.alatus)and isolated populations related to geographical distances.Analysis of molecular variance showed high genetic variation within populations(72.92%for D.alatus and 60.81%for D.costatus)compared to among populations.Bayesian analysis and UPGMA tree also indicated the two optimal genetic clusters related to geographical distances.These results will provide a platform for the conservation,management and restoration of these species.     

Genetic diversity of Betula luminifera populations at different elevations in Wuyi Mountain and its association with ecological factors

The random amplified polymorphic DNA (RAPD) technique was used to evaluate the genetic diversity and population structure of 91 genets from four wild populations of Betula luminifera at different elevations in the National Nature Reserve of theWuyi Mountain, Fujian Province, China. Eighteen random primers (from 139 primers) produced a total of 199 scorable amplified fragments, of which 174 (87.44%) were polymorphic across all individuals. The genetic diversities of B. luminifera at the population level and species level were PPL = 60.05%, h = 0.2242, I = 0.3181 and PPL = 87.44%, h = 0.3442, I = 0.4899, respectively. The value of differentiation (G _st= 0.3486) and analysis of molecular variance (AMOVA) indicated that there was a relatively high genetic differentiation among populations, and about one-third of the genetic variation occurred among populations. Pearson correlation analysis further revealed that the genetic diversity within populations had significant or very significant correlation with the elevation, climatic factors (annual average temperature and annual precipitation) and soil nutrient factors (total nitrogen, C/N ratio and organic matter). Mantel tests show that there was a significant correlation between the genetic distances among populations and the distance of elevation, and the divergence of soil nutrient factors. The results of the present study suggested that the relatively high genetic differentiation among populations of B. luminifera at different elevations might be caused by ecological factors and gene flow. __________ Translated from Scientia Silvae Sinicae, 2008, 44(3): 50–55 [译自: 林业科学]     

思茅松天然种群及其种子园的遗传多样性

采用垂直板聚丙烯酰胺凝胶电泳和水平切片淀粉凝胶电泳技术对思茅松 3个天然种群和思茅松种子园的遗传多样性状况进行了研究。 9种同工酶系统 16个基因位点的分析结果表明 :思茅松天然种群具有较高的遗传多样性 ,多态位点比率P =70 1% ,等位基因平均数A =2 2 7,平均预期杂合度He=0 2 91;群体间的遗传分化程度较低 ,基因分化系数GST=0 0 5 2。思茅松种子园的遗传多样性较天然种群丰富 ,以上各遗传参数值依次为P =73 5 % ,A =2 4 2 ,He =0 2 95 ,种子园营建是林木遗传改良的一种有效途径     

雷州半岛白骨壤遗传多样性的ISSR分

利用ISSR标记技术研究表明：雷州半岛5个白骨壤（Avicennia marina）种群具有较高的遗传多样性。种群之间遗传分化很低,遗传分化系数FST=0.081 2,遗传相似系数平均值为0.980 4,种群间具有较强的基因流（Nm=5.654 9）。通过UPGMA聚类将5个白骨壤种群分为三类,特呈岛种群和角尾种群为一类,企水种群和高桥种群为一类,和安种群单独为一类。和安白骨壤种群可能是雷州半岛最古老的白骨壤种群,应予以优先保护。     

云南4种典型热带丛生竹的种源分化

以典型的自然或栽培种群为研究对象,全面调查和分析了云南4种典型热带丛生竹——巨龙竹、龙竹、云南甜龙竹和黄竹种质资源及其遗传分化背景,并结合种群平均秆径和平均秆质量,初步评价了以种群为代表的各个竹种的种源分化状况。结果显示:4个竹种种群间的平均秆径和平均秆质量等主要营林指标差异显著;巨龙竹、龙竹、云南甜龙竹种群间存在着较高水平的遗传分化,其遗传分化系数(Gst)均大于0.83;而黄竹种群间也存在一定水平的遗传分化(Gst=0.252 4)。研究结果为筛选巨龙竹等4个竹种的优良种源提供了理论依据。     

花叶海棠表型性状变异的研究

在四川省炉霍县和道孚县鲜水河流域调查了花叶海棠6个居群共60个单株,分析比较了树叶和果实的主要营养成分,运用变异系数、方差分析、表型分化系数研究了10个表型性状的变异。结果表明:花叶海棠地径、树高、冠高、冠幅、结实量的居群内方差分量>80％．居群间差异的影响<20％。果实的纵径、横径、重量、果色、果形的变异也主要是由居群内差异引起的,居群间表型分化系数反映果色是以居群间变异占相对优势,纵径在居群间的变异略高于居群内的变异,而横径、果重和果形都是以居群内变异为主。果实维C含量的居群间差异很大,变异系数高达69．04。探讨了花叶海棠的遗传改良策略和资源利用途径。     

我国杉木阴沉木资源的分布和利用

杉木阴沉木系历史上因地震山崩倒埋的杉木形成；由于出土后木材比重比水大，沉于水，故称阴沉木；杉木阴沉木集中分布在我国长江中上游地区，川西南安宁河流域、川滇交界金沙江流域、湘黔交界沅水上游、湘桂交界湘水上游及鄂西南是资源较多的地区；阴沉木对研究杉木植物地理学、育种学、木材学、林产化工及地质与地震等有重要科学价值。     

新疆额尔齐斯河流域苦杨与欧洲黑杨遗传多样性分析

应用SSR标记技术,对新疆额尔齐斯河流域河谷分布的苦杨(Populus laurifoli)和欧洲黑杨(Populus nigra)天然居群的遗传多样性和遗传分化进行了研究。结果显示:苦杨和欧洲黑杨的天然居群具有较高的遗传多样性,且苦杨明显高于欧洲黑杨。与苦杨居群相比,欧洲黑杨居群间基因流较高,居群间的遗传分化程度较小,变异主要源于居群内。苦杨和欧洲黑杨居群内的杂合度较高,各个居群的各项遗传参数都要小于物种水平。苦杨和欧洲黑杨均偏离Hardy-Weinberg平衡,表现为杂合子过量的现象。     

Genetic diversity of sea buckthorn (Hippophae rhamnoides) populations in northeastern and northwestern China as revealed by ISSR markers

As a N₂-fixing tree species, sea buckthorn (Hippophae rhamnoides) is well adapted to arid regions and is utilized for multiple purposes in China. Current knowledge of genetic variability of H. rhamnoides is limited in terms of rangewide distributions. Eleven natural populations of sea buckthorn in northeastern and northwestern China were analyzed to detect genetic variation among and within populations, by use of ISSR (inter-simple sequence repeats) markers. Using eight primers, 207 polymorphic loci were observed, ranging in size from 250 to 2500 bp. The coefficient of gene differentiation (Gst = 0.0679) showed that the total molecular variance of 11 populations was mainly existed within populations. The genetic variation within and among the 11 populations was 93.21 and 6.79%, respectively. No significant correlation between genetic and geographic distances of the populations was found using ISSR markers. Our study provides a population-level genetic profile for further investigation and conservation of genetic diversity of sea buckthorn.