欧洲榛微卫星对我国榛属种质资源的分析

利用多态性高、重复性好的11对欧洲榛微卫星引物对榛属6个近缘种的34个DNA样本进行扩增,共获得81个等位基因,每个座位的等位基因数在4～13之间,平均数目为7.36个,位点的多态信息含量(PIC)介于0.47～0.86,平均为0.73.PCR扩增产物的DNA测序证明欧洲榛SSR基因座位中微卫星序列在6个种内的保守性,而在CAC C28位点,一个被忽略的短三碱基重复序列也表现出长度多态性.另外,对于具有商业潜力的平榛、毛榛、川榛3个种的遗传多样性分析表明,平榛的遗传多样性最高,为0.59.研究结果表明欧洲榛微卫星是用于榛属资源保护、品种改良以及种问遗传图谱构建的有力工具.     

湖北油茶种质资源SSR分析

摘要：利用油茶SSR标记对湖北省的油茶种质资源进行分析,结果表明：10个不同SSR位点所揭示的86份油茶种质间存在较丰富的遗传多样性,平均观察等位基因数为4.9个,平均有效等位基因数为3.2个,平均Shannon 信息指数为1.13,平均杂合度为0.25。36个优良品种的聚类分析结果表明：同一地区的油茶品种相对外地品种具有较近的亲缘关系,且各品种间存在一定的差异,可以利用SSR标记进行品种鉴别。遗传参数受抽样群体大小影响的分析表明：湖北油茶资源的有效等位基因数（Ne）和基因多样度（h）受抽样个体数的影响很大,当样本数达到50时,Ne和h值趋于稳定。     

板栗主要栽培品种的遗传分析

应用RAPD分子标记手段 ,研究了品种间的遗传多样性。对 46个板栗品种样品的DNA ,用 16个引物进行扩增反应 ,产生 69个多态位点。结果表明 ,各个位点上遗传多样性程度存在较大差别 ,有效等位基因数目 (Ne)最大值为 1 9990 ,最小值为 1 0 44 4;基因多样度 (H)的最大值为 0 4998,最小值为 0 0 42 5 ;Shannon信息指数的最大值为 0 692 9,最小值为 0 10 47。所检测位点的平均有效等位基因数目为 1 5 2 6 0 ,平均基因多样度为 0 3618,平均信息指数为 0 4832。有效等位基因数目、平均基因多样度和平均Shannon信息指数的标准误都较小 ,分别为 0 30 96,0 1418,0 1748,估计精度较高。这 3个遗传多样性度量表明板栗品种间具有较高的遗传多样度。品种间遗传距离最大值为 0 80 0 1,相应的遗传共享度为 0 44 93;品种间遗传距离最小值为 0 0 910 ,对应的遗传共享度为 0 9130。遗传距离是评价品种间近缘关系的重要指标。对板栗品种间的遗传分析 ,是板栗良种选育和研究品种间亲缘关系的理论基础     

引进葡萄柚品种基因资源的AFLP分析

采用AFLP分子标记技术,对引进的9个葡萄柚品种基因资源进行分析,评价引进资源的遗传多样性,揭示遗传结构和品种间亲缘关系,为引进葡萄柚品种的进一步开发利用和遗传改良提供基础信息。结果表明,筛选出的7对引物共扩增出263条带,多态带比率为7.22%。多态性标记百分率、观测等位基因数、有效等位基因数、Nei’s基因多样性指数和Shannon信息指数在物种水平分别为7.22%、0.023 4、0.008 0、0.6592和0.258 5,而在品种水平它们分别为2.41%、1.024 1、1.013 2、0.008 0和0.012 2。基因分化系数Gst为0.659,表明葡萄柚的遗传差异主要来自于品种之间。9个品种间的遗传距离变幅在0.000 5~0.037 1之间,平均为0.025 8。基于UPGMA的聚类结果将9个品种分为2组,火焰、矮化、亨路比、哈路比、帕利斯和瑞路比聚为一组,里德马叙、里约红和星路比构成另一组。     

板栗主要栽培品种的遗传学分析

应用RAPD分子标记手段，研究了品种间的遗传多样性。对46个板栗品种样品的DNA，用1个引物进行扩增反应，产生69个多态位点。结果表明，各个位点上遗传多样性程度存在较大差别，有效等位基因数目（Ne）最大值为1．9990，最小值为1．0444；基因多样度（H）的最大值为0．4998，最小值为0．042；Shannon信息指数的最大值为0．6929，最小值为0．1047。所检测位点的平均有效等位基因数目为1．5260，平均基因多样度为0．3618，平均信息指数为0．4832。有效等位基因数目、平均基因多样度和平均Shannon信息指数的标准误都较小，分别为0．3096，0．1418，0．1748，估计精度较高。这3个遗传多样性度量表明板栗品种间具有较高的遗传多样度。品种间遗传距离最大值为0．8001，相应的遗传共享度为0．4493；品种间遗传距离最小值为0．0910，对应的遗传共享度为0．9130。遗传距离是评价品种间近缘关系的重要指标。对板栗品种间的遗传分析，是板栗良种选育和品种间亲缘关系的理论基础。     

迪庆州核桃种质资源的遗传多样性与遗传结构

利用SSR分子标记技术对云南省迪庆藏族自治州3个群体共161份深纹核桃种质资源进行遗传多样性分析,揭示资源的遗传多样性水平及遗传结构特征,为其保护和利用提供依据.结果表明:18对SSR引物对161份DNA样本进行扩增,共检测到171个等位基因,平均每对引物9.5个.3个群体的观察杂合度(Ho)和期望杂合度(He)的变化...     

云杉表型与同工酶遗传多样性研究进展

综述国内外30多年主要云杉属植物的表型与同工酶遗传多样性研究进展、存在问题和发展趋势。群体间(内)表型多样性丰富,群体间性状表型变异一般均呈一定的地理变异模式。同工酶主要遗传多样性参数为：多态位点百分数,平均每个位点的等位基因数目,平均每个位点期望杂合度,有效的等位基因数目和基因分化系数的变幅分别为23％～84．6％,1．33～2．70,0．016～0．306,0．230～1-32和0．022～0．11。群体间的变异量只占总变异量的2％～13%,约87%～98％变异存在于群体内。从表型、同工酶和DNA水平等多层次对云杉的遗传多样性进行偶合研究,同时加强对影响遗传多样性及其结构的外因探讨,及该研究在基因资源保护策略上的应用是云杉遗传多样性研究的发展趋势。     

欧洲黑杨育种基因资源SSR多态性比较研究

本研究利用13对SSR引物对120份(105份国外引进、15份我国新疆)欧洲黑杨基因资源进行了遗传多态性分析,共检测出171个等位基因,每个多态性位点检测到7～19个等位基因,平均为13.2,多态信息指数为0.396～0.909,平均为0.808;遗传距离为0～0.456 4.欧洲黑杨基因种源具有丰富的遗传多样性.通过UPGMA等类分析,将120份材料划分为8类,地理分布较近的材料基本聚在一起,表明遗传距离与地理距离相关性强.     

刺槐群体等位酶分析

等位酶(allozyme)是同工酶的一种,是同一基因位点不同等位基因所编码的一种酶的不同形式,是结构基因编码的产物,遗传和表达遵循孟德尔定律.通过一定方式的电泳,从酶谱上可以分析、识别出编码它们的等位基因,再统计出各种等位基因频率和基因型频率,便可进一步计算出群体的各项遗传学参数,从而了解一个群体的遗传结构(王中仁,1996).对一个物种的遗传结构进行研究,有助于理解该物种的地理变异模式、遗传多样性等,并提供为该物种遗传资源保护、利用做出决策的重要信息(沈浩等,2001;金燕等,2003).等位酶分析方法广泛应用于研究天然居群的遗传结构、基因丰富程度以及栽培植物种质资源遗传多样性及树木种源群体遗传变异模式等(车永和,2003;甘四明等,1998).     

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...     

中国东北林蛙（Rana dybowskii）遗传多样性与分化研究

本文利用11个微卫星多态位点检测东北林蛙(Rana dybowskii)的遗传多样性和种群遗传结构。6个东北林蛙种群的75个个体分布于中国的小兴安岭和长白山地区。11个位点在所有种群中得到的等位基因数为2～10个不等,平均5.6个;平均期望杂合度(HE)为0.572,属于中度多态。基因分化系数(FST)分析表明小兴安岭和长白山地区的种群间遗传分化显著(P<0.001),基于Nei's DA遗传距离构建的UPGMA系统树和AMOVA的结果进一步验证了结论的准确性。因此, 建议将分布于小兴安岭和长白山的东北林蛙划分为两个单独的管理单元加以保护和管理。图2表7参46。     

基于微卫星DNA标记分析刺槐叶瘿蚊遗传多样性指数与样本量的相关性

[目的]探讨基于微卫星标记分析刺槐叶瘿蚊遗传多样性指数与样本量的相关关系。[方法]设置了12个样本量梯度,选取11对微卫星引物分析了我国刺槐叶瘿蚊5个种群的遗传多样性指数。[结果]表明,样本量的大小与平均等位基因数(Na)呈显著正相关,与有效等位基因数(Ne)呈中度正相关,与观测杂合度(Ho)呈负相关,而与期望杂合度(He)、Nei’s遗传多样性指数(H)和多态信息含量(PIC)没有明显相关性。此外,当样本量小于25时,随着样本量的增加,有效等位基因数增幅明显,观测杂合度起伏变化较大,但当样本量大于30时,随着样本量的增加,上述两个指数增(降)幅度平缓。[结论]在利用微卫星DNA标记对我国刺槐叶瘿蚊种群的遗传多样性研究中,选取的最适样本量应为25～30,分析的最适遗传多样性指数应为期望杂合度、Nei’s遗传多样性指数和多态信息含量。该研究结果将为我们后续研究提供科学数据,并有助于分析其他入侵昆虫种群遗传结构的研究,同时可为其他双翅目昆虫的遗传多样性研究提供样本量参考。     

燕山山脉西伯利亚杏的遗传多样性和遗传结构

以西伯利亚杏分布的核心区域燕山山脉地区的17个群体为材料,利用9对微卫星标记进行遗传多样性和遗传结构的分析。在533个个体扩增得到203个等位基因,每位点平均等位基因数为22.556个。分析表明燕山山脉西伯利亚杏群体具有较高的遗传多样性,每位点平均有效等位基因数(Ne)为5.714,多态位点百分率(P)为100%,期望杂合度(He)为0.788。根据有效等位基因数(Ne)、期望杂合度(He)和Shannon信息指数(I)3个遗传多样性参数,遗传多样性最高的群体为北京八达岭,其次为平泉榆树林子,而最低的群体为崇礼驿马图。群体间总的遗传分化系数FST为0.065,总的基因流Nm为3.836。分子方差分析(AMOVA)结果显示燕山山脉地区西伯利亚杏群体的遗传变异主要存在于群体内(95.62%)。Mantel检验发现遗传距离与地理距离呈显著相关性(r=0.5894,P<0.0001)。UPGMA聚类结果显示,地理距离接近的群体聚在一起,进一步验证了Mantel检验结果。基于上述分析结果,提出西伯利亚杏的种质收集策略。研究结果为西伯利亚杏可持续利用与保护提供一定的理论依据。     

Differences of EST-SSR and genomic-SSR markers in assessing genetic diversity in poplar

We analyzed the genetic differences of 16 poplar clones between genomic-SSR and EST-SSR markers.The statistical results show that the average number of alleles detected by genomic-SSR was 4.1,Shannon’s index 1.0646,observed heterozygosity 0.4427 and expected heterozygosity 0.5523,while for the EST-SSR,the average number of alleles was 2.8,Shannon’s index 0.6985,observed heterozygosity 0.2330 and expected heterozygosity 0.4684.Cluster analysis indicated that the EST-SSR capacity of genotypic identification was more precise than that of genomic-SSR.These results reveal that EST-SSR and genomic-SSR have statistically significant genetic differences in polymorphism detection and genotypic identification.These differences could provide a theoretical basis for the rational use of SSR markers in species diversity and other related research.     

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。     

Genetic variability and divergence among Italian populations of common ash (Fraxinus excelsior L.)

The level of genetic variation throughout the Italian range of common ash (Fraxinus excelsior L.) was estimated using six microsatellite markers. High levels of allelic diversity was detected. The levels of expected heterozygosity for each of the populations ranged from 0.726 to 0.871, with an average of 0.798, and indicated that populations have a high level of genetic variation. A general and significant homozygote excess was found at most loci in all populations, with an overall mean F _IS of 0.284. Possible explanations for such situations are discussed. Only 4.9% of the total diversity was attributable to differentiation among populations. Although divergence among pedo-climatic regions explained only a small part of the variance it was possible to observe some partial clustering of populations belonging to the same regions. The contribution of the results in relation to the definition of the most appropriate strategies to collect forest reproductive material is discussed.     

Genetic diversity and population structure analysis of Pistacia species revealed by phenylalanine ammonia-lyase gene markers and implications for conservation

Information on population genetic structure and crop genetic diversity is important for genetically improving crop species and conserving threatened species.The PAL gene sequence is part of a multigene family that can be utilized to design DNA marker systems for genetic diversity and population structure investigation.In the current study, genetic diversity and population structure of100 accessions of wild Pistacia species were investigated with 78 PAL markers.A protocol for using PAL sequences as DNA markers was developed.A total of 313 PAL loci were recognized, showing 100% polymorphism for PAL markers.The PAL markers produced relatively more observed and effective alleles in Pistacia falcata and Pistacia atlantica, with a higher Shannon's information index and expected heterozygosity in P.atlantica, Pistacia vera and Pistacia mutica.Pairwise assessment of Nei's genetic distance and genetic identity between populations revealed a close association between geographically isolated populations of Pistacia khinjuk and Pistacia chinensis.The accessions of wild Pistacia species had more genetic relationship among studied groups of species.Analysis of molecular variance indicated 19% amongpopulation variation and 81% within-population variation for the PAL gene based DNA marker.Population structure analysis based on PAL revealed four groups with high genetic admixture among populations.The results establish PAL markers as a functional DNA marker system and provide important genetic information about accessions from wild populations of Pistacia species.     

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。     

Cross-specific amplification of microsatellite DNA markers in Shorea platyclados

In the megadiverse forests of Southeast Asia,hundreds of timber species are economically important but the population genetics of only a few taxa are known.Cross-specific amplification of microsatellite loci among closely related taxa could enhance our ability to study and manage previously unstudied species. We successfully utilized STMS markers in Shorea platyclados, originally developed for Shorea curtisii. The six primer pairs we tried successfully produced PCR products of expected sizes. The number of alleles observed ranged from 10 to 14 and an average of 12 alleles were detected per locus. A high expected and observed heterozygosity was observed and it ranges from 0.718 to 0.827 among all populations across all six loci tested. Microsatellite DNA markers are highly polymorphic, co-dominant, reproducible, and amenable to high throughput genetic analyses. Overall, the crossspecific amplification of microsatellite loci appears to be complicated by numerous factors. While the approach may be effective for local management and conservation ofpoorly known species, the results must be carefully interpreted.     

Analysis of genetic relationship among Arbutus unedo L. genotypes using RAPD and SSR markers

The strawberry tree (Arbutus unedo L.) is an underutilized, drought tolerant, fire resistant species with a south western distribution in Europe, and with ecological and putative socio-economical impact in Portugal and Mediterranean countries. Our aim was to develop an appropriate set of molecular markers to enable genetic diversity to be assessed and to fingerprint Arbutus unedo genotypes for breeding and conservation purposes in Portugal. Twenty-seven trees from a broad geographic range were screened with 20 random amplified polymorphic DNA (RAPD primers) and 11 microsatellite markers (SSR). The RAPDs generated 124 bands, 57.3% of which were polymorphic, with an expected heterozygosity of 27%. We cross-amplified 11 SSR primers developed for Vaccinium spp., and 5 were found to be polymorphic in A. unedo, with 75% of expected heterozygosity, a number of alleles of 11.6, a null allele frequency of 7.6% and a polymorphic information content of 71%. Although the SSRs were more polymorphic and informative than the RAPDs, both markers displayed high genetic variability with the gathered data. No geographic pattern was observed in the genetic variation distribution based on both marker systems, and the lack of correlation between genetic and geographical matrices was confirmed by Mantel tests. Likely, no correlation was found between pairwise SSR and RAPD band-sharing matrices. These results and their implications on A. unedo breeding and conservation programs are discussed.