柳州蜈蚣蕨群体遗传多样性研究及与南宁群体的比较

采用水平淀粉凝胶电泳技术对广西中部和南部6个蜈蚣陵（PterisvittataL.）种群的遗传多样性进行分析,蜈蚣蕨柳州地区种群都存在一定的遗传变异,多态位点比率P=0．60,等位基因平均数A=1．7,平均期望杂合度He=0．252,高于广西南部南宁地区的蜈蚣蕨种群的遗传变异;Nei的遗传一致度测量结果表明该地区柳州与柳城种群的关系最近,并且地理距离和遗传距离有一定的相关性。     

微卫星分子标记与松浦镜鲤3个表型性状的相关分析

本文利用SPSS13.0分析软件对194尾松浦镜鲤的体重、体长和尾长值进行相关分析,并选用扩增效果好的30个微卫星标记,检测新品种松浦镜鲤繁殖群体的有效等位基因数（Ne）、观测杂合度（Ho）、期望杂合度（He）和多态信息含量（PIC）等遗传参数,以卡方检验估计群体Hardy-Weinberg平衡,最后还将30个基因座的不同基因型与个体的体重、体长和尾长进行了相关分析。结果显示,体重与体长高度线性相关,差异极显著;尾长与体重、体长分别呈显著相关,差异显著。多样性指数结果表明共检测到172个等位基因,片段长度在115～432bp之间,有效等位基因数为1.14～5.32;观测杂合度为0.07～0.92,期望杂合度为0.13～0.91;多态信息含量为0.12～0.79,其中高度多态（PIC≥0.5）21个,中度多态（0.25≤PIC≤0.5）7个,表明这个群体的多样性较高,信息含量比较丰富。我们还发现有4个遗传位点：HLJ328、HLJ693、MFW29和MFW48与体长性状显著相关（P〈0.05）,其中,位点HLJ328、HLJ693和MFW48还与体重性状显著相关（P〈0.05）,未发现与尾长性状相关的位点。本文获得的这些标记具有生长特性优势,可作为松浦镜鲤分子辅助育种的参考标记。     

EST-SSR标记对我国斑点叉尾鮰种质资源的研究

采用EST-SSRs对福建和湖北的1984年群体（P1984）、福建与辽宁的1997年群体（P1997）、湖南的2004年群体（P2004）和福建的1984年与1997年群体杂交的F。代群体（P8497）等4个斑点叉尾鮰（Ictalurus punctatus）养殖群体的遗传多样性进行了研究。结果表明,有10对引物可扩增出清晰条带,其中9对引物具有多态性,共获得32个等位基因,4个群体的平均等位基因数（A）为3．00-3．40,平均有效等位基因数（Ac）为1．95～2．30,平均观察杂合度（Ho）为O．4768-0．5982,平均期望杂合度（Ho）为004913-0．5695,平均多态信息含量（PIC）为0．4113-0．4829,群体间的多态性差异不显著,且各群体的遗传多样性处于中等水平。根据群体间遗传相似性系数、遗传距离及UPGMA聚类分析发现,P1997和P2004群体之间的遗传距离最近,P1984和P2004群体之间的遗传距离最远。4个群体有18．75％的位点偏离了Hardy-Weinberg平衡,表明群体各位点的基因频率和基因型频率稳定性较好。F-统计检验发现,P2004和P8497处于不同程度的杂合子过剩状态,P1984和P1997处于杂合子缺失状态。群体间分化程度很弱,遗传变异主要来自群体内个体之间。     

三种笛鲷的野生群体和养殖群体遗传多样性的微卫星分析

摘要：利用微卫星标记技术,采用10对微卫星引物对南海海域红鳍笛鲷、星点笛鲷、紫红笛鲷3种笛鲷鱼的野生种群（HYE、XYE、ZYE）和养殖种群（HYA、XYA、ZYA）进行了遗传多样性分析。10对微卫星引物在6个群体中共检测到78个等位基因,每个位点的等位基因数目在1~8个之间。6个群体的观测杂合度(Ho)为0.2500~1.0000,平均观测杂合度为：ZYE(0.9550)> ZYA(0.8900),HYE(0.8950)> HYA(0.8400),XYE(0.8450)>XYA(0.8100) ;平均多态信息含量(PIC) 为0.3648~0.7964,各野生群体均大于养殖群体;三种笛鲷鱼的野生群体和养殖群体遗传距离HYE与HYA,XYE与XYA,ZYE与ZYA分别为0.1029,0.0371,0.0135,基因分化系数分别为0.0371,0.0211,0.0352。群体遗传结构分析结果表明：红鳍笛鲷、星点笛鲷和紫红笛鲷的遗传多样性较丰富,养殖群体的遗传多样性较野生群体均有一定程度的降低,野生群体和养殖群体分化较弱。     

利用微卫星标记分析马氏珠母贝4个养殖群体遗传结构

2007年4月,从马氏珠母贝基础群体选取2、4、32和158个亲本分别繁殖4个子代群体,分别命名为P1、P2、P3和P4。2009年7月,从这4个子代群体随机取样30个个体,利用7对微卫星引物分析其遗传结构。结果表明,7对微卫星引物共检测到22个等位基因,每个座位的等位基因数目为2~4个,平均等位基因数为3个,平均有效等位基因数为2.3193。P1、P2、P3和P4群体平均观测杂合度分别为0.4737、0.5489、0.6767和0.7143;P1、P2、P3和P4群体平均期望杂合度分别为0.4737、0.5489、0.6767和0.7143;P1、P2、P3和P4群体的多态信息含量分别为0.4472、0.4224、0.4726和0.4930。本结果表明4个养殖群体均具有较高的遗传多样性,而且有效亲本数目对子代遗传结构有较大的影响,这为马氏珠母贝的遗传育种提供依据。     

桂林地区蜈蚣蕨群体遗传多样性及与南宁地区群体的对比分析

采用等位酶电泳技术,研究了桂林地区的桂林市、雁山镇、永福县的野生蜈蚣蕨群体的遗传多样性,并与南宁地区群体进行比较。所测定的酶系统包括：氨基肽酶（AMP）、还原型辅酶Ⅰ心肌黄酶（DIA）、异柠檬酸脱氧酶（IDH）、苹果酸脱氨酶（MDH）、6-磷酸葡萄糖酸脱氢酶（PGD）、磷酸葡萄糖异构酶（PGI）、磷酸葡萄糖变位酶（PGM）和莽草酸脱氧酶（SKD共8个酶系统,15个酶位点。分析结果表明：桂林地区蜈蚣蕨群体内遗传多样性水平中等偏上,每个位点的等位基因平均为1．7,多态位点百分数为60％,平均期望杂合度为0．251,略高于南宁地区。     

微卫星标记分析广西水牛遗传多样性

为研究广西沼泽型水牛(Bubalus bubalis)核基因组的多态性,采用23对荧光标记微卫星引物,对随机抽取的60个广西本地水牛样本进行了PCR检测。结果表明,23对引物中,有19对可以获得特异性产物且存在多态,平均有效等位基因数为4.0189,基因座ILSTS086含有13个等位基因;各微卫星基因座的平均杂合度变化范围为0.1852~0.4722,ILSTS019基因座平均杂合度最高(0.4722),而ILSTS017平均杂合度最低(0.1852);群体基因平均多态信息含量(PIC)为0.6639,19个标记中有18个PIC大于0.5,属高度多态位点。     

中华鳖5个群体遗传多样性的微卫星分析

利用微卫星分子标记技术对洞庭（DT）、黄河（HH）、黄沙（HS）、日本（RB）以及洞庭（DT）与黄河（HH）的杂交子代（DT♀×HH♂）绿卡（LK）5个中华鳖群体的150个个体进行遗传多样性分析。11对微卫星引物扩增出的等位基因数为3～6个,平均等位基因数为4.1818。5个种群相比,绿卡（LK）的平均有效等位基因数、平均期望杂合度、平均观测杂合度和平均多态信息含量最高,分别是2.3969、0.5274、0.5545和0.4660。对种群间的遗传分化分析表明,黄河（HH）和洞庭（DT）之间的遗传分化最小,为0.0233,而洞庭（DT）和日本（RB）之间的遗传分化最大,为0.0969。基于Nei＇s遗传距离构建的UPGMA系统进化树显示黄河（HH）和洞庭（DT）及其子代绿卡（LK）亲缘关系较近,而与黄沙（HS）和日本（RB）的亲缘关系较远,最远的为日本（RB）群体。     

利用微卫星标记分析边鸡遗传多样性及保种效果

利用21个微卫星标记对2个世代(0世代和1世代)的边鸡(Gallus gallus)群体的遗传结构进行检测,同时通过分析世代间遗传差异检测保种效果.结果表明,21个微卫星标记在2个世代的边鸡群体中共检测到122个等位基因,其中102个为两个世代所共有,19个为0世代所特有.0世代和1世代的边鸡群体的平均多态信息含量(PIC)分别为0.5473和0.5437;平均期望杂合度分别(He)为0.5967和0.6009;近交系数(Fis)分别为0.233和0.134.反映边鸡群体的遗传多样性较丰富,经过一个世代的选育,PIC和He两个指标维持在原有水平,而群体的近交系数有所下降,说明采用的保种方法很好地保存了边鸡的遗传多样性,同时避免了近交程度过高而导致群体出现近交衰退.     

6个野鸭群体的遗传多样性及其与绍兴麻鸭的亲缘关系分析

为了探讨野鸭的遗传多样性和与家鸭的亲缘关系,本研究利用短串联重复序列(short tandem repeat,STR)分型技术对绿头野鸭(Anas platyrhynchos)、西湖野鸭(A.platyrhynchos)、奉化野鸭(A.platyrhynchos)、斑嘴野鸭(A.poecilorhyncha)、针尾野鸭(A.acuta)和赤嘴潜鸭(Netta rufina)6个野鸭群体(共计269只),以及家鸭品种绍兴麻鸭(A.platyrhynchos domestic)60个个体在11个位点上的遗传多样性进行了检测.结果表明,在7个群体中共检测到了141个有效等位基因(effective number of alIeles,Ne),平均有效等位基因为12.821,期望杂合度(expected heterozygosity,He)为0.856,多态信息含量(polymorplism information content,PIC)为0.845.11个位点均为中高度多态位点,适用于鸭的遗传多样性分析.7个群体的遗传多样性丰富,PIC在0.310～0.960之间.F-统计量分析显示,所有位点的Fst在0.047～0.469之间,平均为0.171,表明群体间的遗传变异较大.Nei氏遗传距离分析及系统发育树显示,绿头野鸭、西湖野鸭、奉化野鸭和绍兴麻鸭遗传距离较近,与赤嘴潜鸭、斑嘴野鸭和针尾野鸭的遗传距离较远,同时这3个群体间的遗传距离也较远,并且赤嘴潜鸭单独聚为一类.此外,绍兴麻鸭与绿头野鸭遗传距离远小于其与斑嘴野鸭的遗传距离,提示绍兴麻鸭起源于绿头野鸭的可能性更大.本研究通过对6个野鸭品种的遗传多样性及与绍兴麻鸭的亲缘关系分析,进一步完善了野鸭与家鸭的遗传结构.     

用EST-SSR标记对我国养殖斑点叉尾鮰种质资源的研究

本实验采用EST-SSRs分子遗传标记技术对福州和湖北嘉鱼县的1984年群体（P1984）、福州与辽宁辽中县的1997年群体（P1997）、湖南的2004年群体（P2004）和福州的1984年与1997年群体杂交的F1代群体（P8497)等4个斑点叉尾鮰养殖群体的遗传多样性进行研究。斑点叉尾鮰EST-SSRs是从斑点叉尾鮰ESTs 序列（表达序列标签）中开发的一种新型SSR 标记,这种新型分子标记来源于表达基因,将其用于斑点叉尾鮰遗传研究可直接反映相关基因在不同斑点叉尾鮰群体间的表达差异。本实验检测到两个功能明确的基因位点。实验结果表明有10对引物可扩增出清晰条带,其中9对引物具有多态性,可作为斑点叉尾鮰遗传标记分析,有效的多态性引物占90%,共获得32个等位基因,其中大多数引物有2～4 个等位基因,4个群体的平均等位基因数（A）为3.0000-3.4000, 平均有效等位基因数（ae）为1.9455-2.3024,平均观察杂合度（Ho）为0.4068-0.4732,平均期望杂合度（He）为0.4148-0.4907,平均多态信息含量（PIC）为0.4113-0.4829,群体间的多态性差异不显著,且各群体的遗传多样性处于中等水平。根据群体间遗传相似性系数、遗传距离及UPGMA聚类分析发现,P1997和P2004群体之间的遗传距离最近,P1984和P2004群体之间的遗传距离最远,这验证了四个群体的引入顺序。通过Hardy—Weinberg检验发现,4个群体有18.75％的位点偏离了Hardy—Weinberg平衡, 表明群体各位点的基因频率和基因型频率稳定性较好。通过F-检验发现,P2004和P8497处于不同程度的杂合子过剩状态,P1984和P1997处于杂合子缺失状态。群体间发生分化程度很弱,遗传变异主要来自群体内个体之间。     

Isozyme Polymorphism and Genetic Differentiation in Natural Populations of a New Tetraploid Species <Emphasis Type="Italic">Avena agadiriana</Emphasis>, from Morocco

A new wild tetraploid oat Avena agadiriana Baum et Fedak was collected from the five populations along the Atlantic coast in Morocco. Variations in six enzyme systems were surveyed and allele frequency, percentage of polymorphic loci, number of alleles per locus, observed and expected heterozygosities, and unbiased genetic distance were calculated. Phenotypic frequencies were scored representing 11 polymorphic loci. The mean percentage of polymorphic loci was 46.25, the mean number of alleles per locus was 1.502, and the mean expected heterozygosity was 0.1526. Two heterozygotes resulting from outcrosses were found in the progeny from M60 and M71. The population of M71 had peculiar alleles Est-4A not present in the other populations. Most of the genetic diversity of this species was between populations with little existing within populations. Geographic and genetic distances between populations were positively correlated with each other and the correlation coefficient was 0.7031. Cluster analysis showed two strongly differentiated groups were apparent, M71 and M74, and the remainder. The former group appears to be adapted to man-made habitat, such as road side or eucalyptus plantation, and the latter to a distinct dry, sandy habitat. To make wide intra-specific variation in this species, the modified mating system would be indispensable.     

Investigation of recent population bottlenecks in Kenyan wild sorghum populations (<Emphasis Type="Italic">Sorghum bicolor</Emphasis> (L.) Moench ssp. <Emphasis Type="Italic">verticilliflorum</Emphasis> (Steud.) De Wet) based on microsatellite diversity and genetic disequilibria

Identifying populations that have recently suffered a severe reduction in size is particularly important for their conservation as they are likely to suffer an increased risk of genetic erosion. We investigated the presence of recent bottlenecks in two wild sorghum populations from different eco-geographical conditions in Kenya employing 18 microsatellite markers. Microsatellite analysis showed high allelic diversity in the two populations, with a mean of 4.11 and 6.94 alleles per locus in the North-West wild sorghum population (NWWSP) and the South-East wild sorghum population (SEWSP), respectively. The mean observed heterozygosity was 0.34 and 0.56 in NWWSP and SEWSP, respectively. A large long-term effective populations size for both populations was observed assuming either an infinite allele model or a stepwise mutation model. There was no apparent loss of genetic variability for either of the populations. Test of heterozygosity excess indicated that a recent bottleneck in the two populations is highly unlikely. Furthermore, analysis of the allele frequency distribution revealed an L-shaped distribution which would not have been observed in case a recent bottleneck had reduced genetic variability in the two populations. The fact that most loci displayed a significant heterozygosity deficiency could be explained by population subdivision and the mixed mating system exhibited by wild sorghum populations. Furthermore, the possibility of a historical expansion of wild sorghum populations and presence of null alleles could not be ruled out.     

江西青岚湖五种淡水蚌遗传多样性的微卫星DNA分析

利用北美Epioblasma capsaeformis（蚌科）和中欧Margaritifera margaritifera L.（珍珠蚌科）两种淡水双壳类的20对微卫星引物对江西青岚湖五种淡水蚌群体进行了PCR扩增，筛选出8对多态性较高的引物，并用这8个微卫星座位分别对三角帆蚌、褶纹冠蚌、洞穴丽蚌、射线裂脊蚌和中国尖嵴蚌五种蚌类群体进行了遗传多样性分析。结果表明：不同蚌类群体的平均等位基因数为2.8750～4.000，平均观测杂合度（HO）为0.4417～0.6333，平均期望杂合度（HE）为0.4430～0.5706，平均多态信息含量（PIC）为0.368～0.498，五个群体表现出较高的遗传多样性。有多个座位在不同蚌类群体中偏离哈代－温伯格平衡。五种蚌类群体间的遗传距离在0.6228与1.4724之间，三角帆蚌和褶纹冠蚌之间的遗传距离最大，射线裂脊蚌和洞穴丽蚌之间的遗传距离最小。     

江西野生毛花猕猴桃群体SSR遗传多样性研究

为分析江西野生毛花猕猴桃群体遗传多样性,以江西省境内的5个野生毛花猕猴桃雄性群体(72个个体)为试验材料,采用SSR分子标记技术,选取15对多态性引物,利用聚丙烯酰胺电泳对PCR产物进行检测。结果表明,15对SSR引物共检测到86个位点,多态性位点百分率为100.0%;观察到的平均等位基因数为5.733,有效等位基因数为3.002,Shannon信息指数为1.046。表观杂合度介于0.111~0.819之间,预期杂合度介于0.041~0.876之间,遗传分化系数为2.01,野生毛花猕猴桃雄性群体间存在较大的遗传分化。5个毛花猕猴桃雄性群体遗传距离范围为0.102~0.409,遗传相似度范围为0.665~0.903,群体间遗传距离与地理距离无相关性。群体的遗传多样性丰富度依次为庐山>井冈山>南源山>武功山>麻姑山,江西地区供试的野生毛花猕猴桃雄性群体在分子水平上具有丰富的多态性。本研究结果为毛花猕猴桃雄性品种选育、种质创新与利用提供了一定的理论基础。     

中国板栗SSR标记的研究

本研究从中国板栗“艳红”中分离到25个SSR标记。为了鉴定SSR位点，在重复序列的两侧侧翼序列设计引物，并通过化学荧光检测法对6个板栗样品进行检测，共检测到18个多态性位点，每个位点的等位基因数为2~6个。挑选12个位点，通过半自动系统ABI PRISM 377对中国北方24个板栗品种进行分析，这12个标记显示了高达共75个等位基因的遗传多态性，每个位点的等位基因为4~10个，平均为6.3个，预期的平均杂合性为0.743（介于0.680~0.845），检测到的平均杂合性为0.829（介于0.730~0.930）。无效等位基因估算频率显示为3个位点的正向价值，除了一个位点外，这些价值都很低，鉴定机率为7.01×10-11，亲缘关系鉴定机率非常高，为0.999，足够用于花粉流的研究。     

Genetic diversity and population structure of Guinea yams and their wild relatives in South and South West Ethiopia as revealed by microsatellite markers

Genetic diversity and population structure of Guinea yams and their wild relatives collected from south and south west Ethiopia were assessed using microsatellite markers. The total number of alleles amplified for the 7 loci studied was found to be 60, with an average of 8.6 alleles per locus. The average expected heterozygosity for the entire population was found to be 64 % indicating that Guinea yams and their wild relatives in the study area display a high level of genetic diversity. Using allelic richness as a measure of genetic diversity the wild forms exhibited greater allelic diversity than the cultigens. Contrary to what is expected in vegetatively propagated crops, none of the seven loci studied showed a significant excess of heterozygotes. In all the comparisons made, a low mean F_ST (but significant) has been observed, indicating that the majority of microsatellite diversity in the populations under study was found within rather than between populations.     

Geographical, altitude and agro-ecological differentiation of isozyme and hordein genotypes of landrace barleys from Ethiopia: implications to germplasm conservation

An analysis of the variability of genes encoding six isozyme systems (15 loci) and two storage proteins (2 loci) in landrace barley from Ethiopia is reported. The materials consisted of populations collected from sites as low as 1650 and as high as 3750 meters, covering a wide range of agro-ecological conditions and geographical areas. Of the 17 loci 7 were polymorphic and 10 monomorphic when the 95% criterion of polymorphism was applied. Despite the disproportionate monomorphic loci, polymorphism was detected in all populations when this criterion is used. The populations were found to possess fairly low mean number of alleles per locus (A = 1.5), low mean value of expected heterozygosity (H = 0.134) and a fairly high mean percentage of polymorphic loci (P = 35.3%). The mean F_ST= 0.474 for the populations is typical of inbreeding species. The result indicated that allelic richness is concentrated in altitude class 3 (2500–3000 m) followed by altitude class 1 (<2000 m). Altitude class 2 (2000–2500) holds an intermediate place though it is the highest in terms of expected heterozygosity (H = 0.245). Higher genetic diversity is concentrated in some geographical regions such as Shewa, Arsi, Bale compared to others (Welo, Gamu Gofa, Gojam). Genetic differentiation among the agro-ecological zones was more profound than both among the altitudes and among regions. Correlation analysis between phenotypic diversity (Shannon-Weaver diversity index) and expected heterozygosity (H) for isozyme/hordein loci revealed non significant associations except with respect to agro-ecological zones. In general, it was detected that sites in highland areas in central and northern regions may be more desirable for in situ conservation than sites in peripheral regions in terms of isozyme/hordein diversity and current rate of varietal replacement.