共查询到20条相似文献，搜索用时 93 毫秒
1.
利用EST-SSR标记分析西南扁穗牛鞭草种质的遗传多样性 总被引：2，自引：2，他引：0
利用禾谷作物EST-SSR标记对采自我国西南地区的40份野生扁穗牛鞭草和3份扁穗牛鞭草国审品种的遗传变异和亲缘关系进行了研究。试验筛选出23对引物对43份供试材料进行扩增,共获得323条带,其中多态性条带261条,多态性条带比率(PPB)达80.4%,多态信息含量(PIC)为0.354~0.500,平均值为0.474,遗传相似系数(GS)为0.690~0.913,表现出丰富的遗传多样性。聚类分析结果表明,各供试材料间的聚类与其地理来源及形态特征具有一定的相关性。5 个扁穗牛鞭草地理类群间的分子方差分析(AMOVA)揭示了供试的扁穗牛鞭草类群内的遗传变异占总变异的95.32%,类群间变异占总变异的4.68%。表明禾谷作物的EST-SSR能用于扁穗牛鞭草遗传多样性研究,是一种有效的分子标记。本研究结果为扁穗牛鞭草种质的收集、利用及育种提供了理论依据。 相似文献
2.
青藏高原喜马拉雅嵩草的遗传多样性研究 总被引：1，自引：1，他引：0
应用随机扩增多态DNA(RAPD)方法对青藏高原东部喜马拉雅嵩草的遗传多样性进行了研究,结果表明:在居群水平与物种水平上喜马拉雅嵩草都存在比较丰富的遗传多样性,多态位点百分率(PPB%)分别为70.23%和81.82%;Nei's基因多样度(h)分别为0.2446和0.2738;Shannon's信息指数(Ⅰ)分别为0.3662和0.4099.AMOVA数据表明,喜马拉雅嵩草的遗传变异主要分布在居群内,居群内变异占总变异的89.06%.遗传分化系数(Gst)也显示了相似的结果,为0.1066.综合各项指标表明,喜马拉雅嵩草符合风媒异交的繁育系统特征. 相似文献
3.
利用ISAP标记对来自中国西南地区的44份扁穗牛鞭草(Hemarthria compressa)无性系材料的遗传多样性和群体遗传变异进行了分析研究。结果表明:从72对引物中筛选出19对扩增条带清晰、稳定性好的引物,共扩增出432条带,其中有316条带具有多态性,多态性条带比例(PPB)达73.15%,多态性信息量(PIC)在0.161~0.312之间,平均值为0.269,Shannon多样性指数(H)平均值为0.399,标记指数(MI)平均值为4.584,分辨率(RP)平均值为9.419,基因型指数(GI)平均值为0.937。各无性系间的遗传相似性系数(GS)在0.464~0.908之间,平均值为0.614。UPGMA聚类分析与基于模型的STRUCTURE分析结果相似,显示供试材料间的遗传关系与其地理来源无明显的相关性,采用AMOVA分析对2种方法划分的类群发现大部分变异来自于群体内部。表明ISAP标记能有效地用于扁穗牛鞭草遗传多样性以及基因型鉴定,同时为扁穗牛鞭草无性系的保存、鉴定和新品种选育提供理论依据。 相似文献
4.
蒙古冰草遗传多样性的等位酶分析 总被引：18，自引：3，他引：15
采用聚丙烯酰胺凝胶电泳技术检测了内蒙古中东部地区蒙古冰草6个天然居群和2个栽培品种的遗传多样性和居群结构，12个酶位点的多态位点百分率为67.71%，基因多样性指数（He)为0.285，显示出了较高的遗传多样性，从遗传多样性的分布格局来看，8个居群的遗传分化系数Gsr=0.129，表明在总的遗传变异中，只有12.9%的变异存在于居群间，而87.1%的变异存在于居群内，同时，6个天然居群的总基因多样度（HT=0.439)和基因分化系数（GST=0.032)也大于2个栽培品种的相应值（HT=0.423,GST=0.010)。UPGMA聚类分析的结果表明，蒙古冰草居群间的遗传分化与生态环境因子间有着密切的相关性。 相似文献
5.
采用ISSR分子标记技术对不同放牧强度下冰草自然居群的遗传多样性进行了研究。结果表明,放牧导致冰草部分位点丢失,但整个冰草居群仍表现出丰富的多态性,ISSR检测的多态性条带比率为96.46%,居群间的遗传差异很小,放牧并未使冰草居群产生遗传分化。由Shannon’s和Nei’多样性指数检测的各个引物在4个冰草居群内的遗传多样性的大小排列顺序为:中度放牧样地重度放牧样地无放牧样地轻度放牧样地。 相似文献
6.
利用线粒体DNA中的NADH脱氢酶第二亚基(ND2)对来自齐齐哈尔市50个崖沙燕(Riparia riparia)样本进行扩增和测序,发现了11条新的单倍型序列。结合从GenB ank中下载的104条序列,对崖沙燕3个亚种种群(154只个体)进行序列变异及系统发育分析。结果显示,3个亚种种群中有2个共享单倍型。群体总的单倍型多样性(Hd)为(0. 885±0. 019),群体总的核苷酸多样性(Pi)为(0. 002 92±0. 000 18)。与其近缘物种淡色崖沙燕(Riparia diluta)相比较,崖沙燕种群表现出较低水平的遗传多样性。分子方差分析(AMOVA)显示变异主要来自种群内(72. 82%)。构建的单倍型系统发育树表明,62个单倍型没有形成明显的亚种分化和地理分化。 相似文献
7.
桑树种群遗传结构变异分析 总被引：6，自引：2，他引：4
基于探讨桑属植物种群间遗传变异规律 ,采用显性分子标记RAPD技术 ,对我国桑树现行分类的 15个种、4个变种及近缘属的 4 8份供试材料进行了桑属种群的遗传结构分析。结果表明 :桑树具有丰富的遗传多样性 ,多态位点百分率为 78 95 % ;Nei′s基因多样性指数 (h)与Shannon多样性指数 (I)具有相同的群体遗传多样性评价结果 ,即种群组成差异越大 ,h与I指数越大 ,桑属种群的h指数为 0 1893,I指数为 0 30 91;桑属种群总基因流值Nm<1(0 5 2 2 0 ) ,基因分化系数Gst为 0 4 75 3;AMOVA分析表明种群内的变异百分率为 72 6 5 % ,种群内的变异大于种群间 ;UPGMA聚类结果与基因流值、基因分化系数有密切的关系 相似文献
8.
四川青衣江、岷江流域鹅观草遗传多样性的溶蛋白分析 总被引：4，自引：0，他引：4
用酸性聚丙烯酰胺凝胶电泳(A-PAGE)技术对采自青衣江流域和岷江流域的97份鹅观草材料的种子醇溶蛋白进行了分析。在对四川青衣江、岷江流域鹅观草居群的醇溶蛋白分析中,鹅观草材料醇溶蛋白带谱存在显著差异,共出现27个条带,其中多态性条带25条,占总条带数的92.59%;鹅观草的遗传相似性与其地理分布较为一致,表现在:1)青衣江、岷江流域鹅观草总遗传多样性指数为0.345 1,其中青衣江流域鹅观草遗传多样性指数为0.340 0,岷江流域鹅观草遗传多样性指数为0.310 0,表明青衣江流域鹅观草比岷江流域存在更为丰富的遗传变异,多样性指数更高;但流域间遗传分化系数仅为0.04,表明两江流域间遗传分化较小;各居群间遗传变异系数达0.326,表明总遗传多样性的32.6%来自居群间。2)在同一流域不同居群也存在遗传分化,其中青衣江流域各居群(除峨眉山居群分散聚在各居群外)能聚在一起;而岷江流域各居群在成都平原区段互相渗透,但能以上、中、下游区段聚开;青衣江流域各居群中以蒙山居群遗传多样性指数最高,达0.339 8,洪雅居群最低,仅0.094 7;岷江流域上游居群多样性指数最高,为0.301 7,而下游以乐山居群遗传多样性指数最低,为0.131 7。3)同一居群内鹅观草存在遗传变异,两江流域以蒙山居群变异最大,多样性指数最高。对居群遗传多样性的研究还表明,鹅观草垂直分布的遗传多样性高于水平分布;在成都平原居群由于生境片断化,导致岷江流域鹅观草生境片断化后小居群遗传分化增加,而整个成都平原“大居群”遗传多样性降低。 相似文献
9.
为评价新疆狗牙根(Cynodon dactylon)资源的遗传多样性水平,以采自新疆不同地域的狗牙根与部分华南地区及国外的狗牙根为材料,用SSR标记开展遗传多样性研究.结果表明:20对引物共产生142个等位变异,平均每个位点7个,其中有124个等位变异显示多态性,多态位点百分率为87.86％,位点Nei's基因多样性(H)指数平均为0.4347;根据遗传一致性及遗传分化结果,106份狗牙根材料的遗传相似性系数值在0.43～1.0之间,平均0.715,居群间遗传分化系数为0.4119,表明有41.19％的变异存在于居群间,58.81％的变异存在于居群内,居群内的遗传分化大于居群间的遗传分化;根据UPGMA法聚类表明,106份供试材料相似系数为0.39时可聚为3类,材料间的遗传差异与其采集地的关系不很明显,但来自同一地区的材料较多地聚在一起,遗传背景较近,整体来看聚类结果与地理来源有一定的相关性. 相似文献
10.
蒙古韭不仅是荒漠草原上较好的饲草之一,而且其特殊气味和丰富的营养也可以作为野生蔬菜开发利用。为了能够保护且合理利用这一资源,试验采用SSR分子标记法,对来自内蒙古自治区和甘肃省的8个地理居群蒙古韭材料进行遗传多样性分析。研究结果表明:通过SSR分子标记共检测出112条多态性位点,每个SSR位点的多态性信息含量(PIC)平均为0.3228,变幅在0.20840~0.4076之间。种间Nei’s基因多样性指数(He)变幅为0.1588~0.3956,Shannon信息指数(Ⅰ)介于0.2637~0.5790之间;8个居群种内Nei’s基因多样性指数(He)变幅为0.0926~0.1743,Shannon信息指数(I)在0.1394~0.2657之间,体现出较为丰富的遗传多样性,且种内遗传多样性水平差异较大。遗传基因分化系数(Gst)平均为0.5532,说明种群间存在丰富的遗传变异。UPGMA聚类分析法将8个居群分为2个大类群,综合地理分布及距离分析得出遗传距离与地理生境有关,特别是与年均温和纬度关系比较明显。其研究结果可为蒙古韭引种驯化及遗传育种提供依据。 相似文献
11.
12.
13.
In this paper we discuss the use of genetic engineering in livestock production. We examine the main two different aspects of genetic engineering: cloning and transgenesis. After commenting what has been expected from both techniques in livestock production in the last 25 years, the practical difficulties for implementing cloning and transgenesis are examined. Apart from technical difficulties, problems derived from the detection of genetically superior animals and evaluation of the clones and the transgenic animals make these techniques less interesting than they appear to be. Most of the observed variability of the economically interesting traits is not genetic, genetic evaluation needs a large number of animals and cloning success will represent a serious loss of genetic variability and the loss of the flexibility needed for markets in constant evolution. There is a risk in transgenic animals of production of new intermediate biochemical products that may be toxic, allergenic or carcinogenic. The benefits produced by transgenic animals hitherto hardly justify this risk. The expectations that genetic engineering produced 25 years ago should be re-examined, considering the risks and the high investment required. 相似文献
14.
D.P. O'Brien T. Leeb 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2014,28(4):1186-1198
DNA testing is available for a growing number of hereditary diseases in neurology and other specialties. In addition to guiding breeding decisions, DNA tests are important tools in the diagnosis of diseases, particularly in conditions for which clinical signs are relatively nonspecific. DNA testing also can provide valuable insight into the risk of hereditary disease when decisions about treating comorbidities are being made. Advances in technology and bioinformatics will make broad screening for potential disease‐causing mutations available soon. As DNA tests come into more common use, it is critical that clinicians understand the proper application and interpretation of these test results. 相似文献
15.
利用12对微卫星引物对毛乌素沙地油蒿种群的遗传分化、基因流进行分析,采用Nei’s指数和Shannon指数估算3个不同类型沙地种群的遗传多样性,计算种群相似系数和遗传距离,利用遗传距离构建系统树。结果表明:(1)种群遗传多样性分析显示,油蒿种群多态位点百分率为100%,说明油蒿种群基因组ISSR具有较高的多样性。(2)在遗传距离为6.0处可将184个样株大致分为三类,涵盖了135个样株,占采样总量的73.34%。结合样地定位记录,聚类结果与样株空间分布具有一致性,即可分为流动沙地、固定沙地、半固定沙地油蒿种群。(3)流动沙地与固定、半固定沙地油蒿种群间的基因流较小,分别为0.7929和0.6848,半固定与固定沙地油蒿种群间存在着较高的基因流,为6.2930。半固定与固定沙地种群间的遗传一致度较高,为93.77%;流动沙地种群Shannon指数低。 相似文献
16.
基于SSR分子标记的药用黄芪遗传多样性与遗传结构分析 总被引：1，自引：0，他引：1
为了能更好的了解药用黄芪（Astragali Radix）遗传多样性及遗传结构,本试验利用10对SSR引物对来自17个产地共380个样本的蒙古黄芪、膜荚黄芪进行遗传多样性及结构分析,结果显示药用黄芪具有较高程度的遗传多样性水平（I=2.112,H=0.781）,其中蒙古黄芪遗传多样性水平（I=2.241,H=0.804）要高于膜荚黄芪（I=1.982,H=0.757）,且两种黄芪的遗传变异主要发生在居群内;UPGMA聚类分析及STRUCTURE居群遗传结构分析可将其分为3组,即膜荚黄芪为单独一组,蒙古黄芪分为两组,其中来自山西产区的大部分居群分为一组,来自内蒙产区及部分山西产区的居群分为另一组。本研究结果对药用黄芪种质资源的有效利用、遗传多样性的保护、育种及开发优质黄芪种质资源提供一定的理论基础。 相似文献
17.
A review of genetic parameter estimates for wool, growth, meat and reproduction traits in sheep 总被引：3，自引：0，他引：3
Genetic parameters for a range of sheep production traits have been reviewed from estimates published over the last decade. Weighted means and standard errors of estimates of direct and maternal heritability, common environmental effects and the correlation between direct and maternal effects are presented for various growth, carcass and meat, wool, reproduction, disease resistance and feed intake traits. Weighted means and confidence intervals for the genetic and phenotypic correlations between these traits are also presented. A random effects model that incorporated between and within study variance components was used to obtain the weighted means and variances. The weighted mean heritability estimates for the major wool traits (clean fleece weight, fibre diameter and staple length) and all the growth traits were based on more than 20 independent estimates, with the other wool traits based on more than 10 independent estimates. The mean heritability estimates for the carcass and meat traits were based on very few estimates except for fat (27) and muscle depth (11) in live animals. There were more than 10 independent estimates of heritability for most reproduction traits and for worm resistance, but few estimates for other sheep disease traits or feed intake. The mean genetic and phenotypic correlations were based on considerably smaller numbers of independent estimates. There were a reasonable number of estimates of genetic correlations among most of the wool and growth traits, although there were few estimates for the wool quality traits and among the reproduction traits. Estimates of genetic correlations between the groups of different production traits were very sparse. The mean genetic correlations generally had wide confidence intervals reflecting the large variation between estimates and relatively small data sets (number of sires) used. More accurate estimates of genetic parameters and in particular correlations between economically important traits are required for accurate genetic evaluation and development of breeding objectives. 相似文献
18.
E. Thorn Hellsten A. Nsholm H. Jorjani E. Strandberg J. Philipsson 《Livestock Science》2009,121(2-3):207-214
The objective of this study was threefold: 1) To survey the use and impact of foreign stallions in the Swedish Warmblood (SWB) breed 2) To investigate the impact of including genetic groups in the genetic evaluation of the SWB and 3) To estimate the impact of incomplete pedigree information on the estimated breeding values (EBVs) for stallions. Data consisted of 189,330 horses of which 50,907 had performance information. Studbook of origin was determined for stallions with at least 5 progeny tested in Sweden. Those 757 stallions had together 116,505 progeny registered in the SWB. Genetic groups were formed according to preliminary analyses of the genetic levels in dressage and show jumping of the different populations. During the first studied period, comprising horses born before 1980, about 80% of the foals were sired by Swedish born stallions, whereas these only sired 40% of the horses born 1990–2003. In this period Holstein stallions had sired 21% of the foals and Dutch stallions (KWPN) 10%. The proportion of mares covered by foreign stallions increased after the early 1980s to about 80% in 2006. Some of the foreign populations, e.g., Holstein, Selle Francais and KWPN, have significantly affected the show jumping performance level of the SWB breed in the past although the deviation from SWB stallions has become smaller over time. Regarding dressage, no particular foreign population has consistently shown such an impact on the performance although Oldenburg stallions seem to be influential lately. The pedigree completeness (PEC values) of the horses included amounted on average to 0.845 for horses with performance data and to 0.907 for stallions with at least 15 progeny. Foreign stallions had an average PEC value of 0.858. When simulating no pedigree information available for foreign stallions, the EBVs of these stallions changed on average by 19–22 index units, which equals about one genetic standard deviation. Thus, keeping complete and correct pedigree registers is crucial for the assessment of reliable EBVs of SWB horses. Including genetic groups in the genetic evaluation of the SWB resulted in hardly any re-ranking of horses. Correlations between EBVs were about 0.99. Inclusion of genetic groups caused larger standard errors of the EBVs. Furthermore, as the pedigrees on average have great depth, and partially also because Warmblood sport horses have become a mix of many different populations, it was not recommended to include genetic groups in the model for future routine genetic evaluations of SWB. 相似文献
19.
Ubbink GJ Van den Ingh TS Yuzbasiyan-Gurkan V Teske E Van de Broek J Rothuizen J 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2000,14(2):172-176
Inherited copper toxicosis in Bedlington terriers was 1st reported in 1975 and the entire Dutch population was examined from 1976 until the present for presence of the disease. To examine the effect on the prevalence of the disease of excluding affected dogs from breeding we have compared 2 time cohorts, the 1st consisting of dogs born from January 1, 1976, to January 1, 1986 (n = 155), and the 2nd of dogs born from January 1, 1990, to January 1, 1997 (n = 195). The diagnosis was made in the 1st cohort by evaluating liver biopsies, and in the 2nd cohort with a DNA marker. The population was also resolved into clusters of related dogs to analyze the familial distribution of the disease in the population and to search for ancient founders of the disease among the ancestors of sick dogs. Forty-six percent of dogs examined between 1976 and 1986 had copper toxicosis. Eleven percent of dogs examined in the 2nd cohort had evidence of disease. This reduction was achieved while maintaining the already limited genetic heterogeneity of the population: the number of clusters and the mean relatedness between the clusters were similar in both time cohorts. The disease was evenly distributed over the clusters of related dogs in both cohorts. All ancestors had contributed to the distribution of copper toxicosis and no specific founders could be identified. This indicates that when the breed was established in The Netherlands, the disease was already highly prevalent in the founding dogs. 相似文献
20.
Two Chinese domestic yak populations representing the Plateau type and the Huanhu Alpine type were analysed with 12 bovine microsatellite primers. All primer pairs functioned in the yak genome and polymorphism was found at all loci. The allele size ranges and frequencies of the two yak populations were similar and there was considerable overlap with the allele size ranges observed in cattle. Data for European cattle breeds was obtained from the Cattle Diversity Database(CaDBase)to interpret the heterozygosity and genetic distance estimates in yak populations. Heterozygosity estimated for the two yak populations was comparable to that of European cattle while Nei's Genetic Distance DA between the two yak populations was less than distances between the most closely related German cattle breeds. Bovine microsatellite primers proved to be a valuable tool for characterization of yak populations. 相似文献