海南两个自然保护区野生荔枝遗传多样性研究

采用常规聚丙烯酰胺凝胶电泳技术,对海南吊罗山和霸王岭两个国家级自然保护区野生荔枝等位酶遗传多样性进行了研究。13个酶系统、18个酶位点的检测结果表明,两个自然保护区野生荔枝具有较低的居群间遗传变异水平和较高的居群内遗传变异。吊罗山保护区野生荔枝的遗传多样性参数为:P=61.1%,A=2.05,He=0.27。霸王岭居群野生荔枝的遗传多样性参数为:P=61.1%,A=2.05,He=0.28。两个群体的遗传分化极小,GST=0.047.居群间遗传一致度较高I=0.977。共检测到7个稀有等位基因。两个自然保护区的野生荔枝均有各自特有的稀有等位基因,都应采取措施予以保护。     

基于SSR标记构建燕山板栗核心种质

探讨分子水平构建燕山板栗核心种质的适宜方法,以利于燕山种质的保存、保护和研究利用.基于SSR标记,采用非加权算数平均聚类(UPGMA)法对燕山地区10个市(县)的161份板栗种质进行多次聚类抽样分析,比较使用3种遗传相似系数(SM系数、Dice系数和Jaccard系数)和2种取样方法(随机取样法和位点优先取样法)相组合确定的不同样本群的有效等位基因数(Ne)、Nei′s多样性指数(H)和Shannon′s信息指数(I)的大小,确定构建燕山板栗核心种质的适宜方法;再分别对核心种质与原种质、核心种质与保留种质的遗传多样性指标进行t检验,以评价核心种质的代表性;通过绘制主坐标分布图观察核心种质和原种质的分布情况,并结合表型特征对构建的核心种质进行确认.结果表明:应用位点优先取样法取得的样本群比随机取样法具有更高的Ne、H和I,应用SM系数取得的样本群,其遗传多样性指标要优于Dice系数和Jaccard系数,综合利用位点优先取样法和SM系数筛选了46份燕山板栗核心种质,保留了原种质28.57％的样品,Ne、H和I分别为1.5317,0.3218和0.4910.t检验表明,核心种质的遗传多样性指标显著大于原种质,经主坐标分析和表型特征确认,核心种质在原种质的主坐标图中分布均匀,能够较全面地代表整个板栗种质资源的遗传多样性.采用位点优先取样法和SM相似性系数进行多次聚类,是构建燕山板栗核心种质较适宜的方法,构建的容量为46份的板栗核心种质,能充分代表原种质的遗传多样性.     

基于SSR分子标记的闽楠(Phoebe bournei)核心种质的构建

为更好地发掘和利用现有闽楠种质资源,本研究利用7个SSR位点对江西和福建16个闽楠群体的237份材料进行基因型分析,采用逐步聚类(随机取样策略,位点优先取样策略)和模拟退火算法(等位基因数目最大化策略,遗传距离最大化策略)4种取样方法构建闽楠核心种质,并将各遗传多样性指标进行分析。结果表明:7个SSR位点共检测到50个等位基因,平均为7.143,平均有效等位基因为2.115,Shannon信息指数为0.778,观测杂合度为0.302,期望杂合度为0.442。基于逐步聚类方法构建的核心种质相较于基于模拟退火算法构建的核心种质各遗传参数指标都相对较高。对其进行t检验后,选择以基于逐步聚类位点优先取样策略在25%的取样比例下选取的种质为核心种质,其等位基因数、平均有效等位基因数、多态性位点百分率、Shannon多样性指数的保留率分别为初始种质的98%、104.92%、90.09%、97.94%。筛选出的59份核心种质材料能够较好地代表闽楠种质资源的遗传多样性,为闽楠的种质资源保存提供科学依据。     

乌桕种质资源分子标记评价及核心种质初步构建

本研究应用SRAP标记技术,利用10对高效多态性标记对128份乌桕种质资源的遗传多样性进行分析,再根据逐步聚类和随机取样2种方法进行组内个体选择,构建了包含有17份种质的初级核心种质库,结果显示128份乌桕种质资源变异丰富,多态性较高,构建的核心种质保留了13%的初始种质,比较核心种质和初始种质遗传多样性保留率(多态性位点83.95%,观测等位基因数92.17%,有效等位基因数101.79%,Nei's遗传多样性指数104.52%,Shannon's信息指数102.09%)符合核心种质的要求,表明本研究所构建的核心种质很好的保留了原始种质的遗传多样性。     

基于ISSR标记分析连云港地区野生灵芝种质资源遗传多样性及亲缘关系

为分析连云港地区野生灵芝种质资源之间的亲缘关系和多样性水平,以连云港地区15株野生灵芝为研究对象,采用ISSR分子标记进行遗传多样性及亲缘关系分析。15株野生灵芝中扩增出多态性条带为40条,片段大小在250～2000 bp之间,平均等位基因位点1.8个,平均有效等位基因数1.2454,平均Nei’s遗传多样性0.1742,平均Shannon信息指数0.2925,有效等位基因数(Ne)的变化范围为1.0000～1.6423,Nei’s遗传多样性(He)的变化范围为0.1031～0.3911,Shannon信息指数(I)的变化范围为0.2235～0.5799,根据ISSR分子标记的遗传聚类图,15株灵芝相似系数范围在0.415～0.866之间,相似系数为0.63时,可以将15株野生灵芝分为四组。研究结果为连云港地区灵芝种质资源分类、保护和品种创制提供了参考依据。     

天山樱桃野生居群遗传多样性ISSR分析

利用ISSR标记技术对新疆天山樱桃的4个野生居群44份种质的遗传多样性进行分析。研究发现26条ISSR引物共检测到236个位点,其中多态性位点175个。Nei's基因多样度指数(H)和Shannon信息指数(I)分别为0.207 3和0.318 8,各居群间遗传分化系数(Gst)为0.228 2,基因流(Nm)为1.691 1,认为天山樱桃遗传分化水平较低,居群间基因交流频繁,遗传变异主要存在于居群内。基于遗传距离(GD)的聚类图可知,喀拉峻与大西沟居群遗传关系最近,与裕民县居群遗传距离(GD)较远,4个天山樱桃居群中大西沟居群遗传多样性最高,本研究可为天山樱桃种质资源的有效保护和利用提供理论依据。     

梨属植物等位酶遗传多样性研究

利用超薄平板微型聚丙烯酰胺凝胶的等电聚焦电泳技术,对286份梨材料进行了等位酶遗传变异分析。在8个酶系中共检测到19个清晰位点和82个等位基因,19个位点均为多态位点,位点最大等位基因数为6,体现出梨丰富的遗传种质多样性;不同的居群具有特有等位基因;通过82个等位基因可以将286份材料完全区分开,表明等位酶基因型指纹可用作梨品种区分与鉴定的依据。     

不同居群朱砂根(Ardisia crenata)的荧光ISSR遗传多样性分析

为了从分子水平揭示福建省不同野生居群朱砂根的遗传多样性水平,本研究采用荧光ISSR分子标记对福建省20个朱砂根野生居群共255个样株的遗传多样性及遗传结构进行了分析。5条ISSR荧光引物共扩增出谱带为186条,其中多态性谱带为96条,多态性平均百分率达到55.77%。居群的多态位点百分比(PPL)在37.65%～80.39%之间,观测等位基因数(Na)在1.376 5～1.803 9之间,Shannon指数在0.200 0～0.367 2范围内,Nei's基因多样度(H)于0.125 6～0.242 5之间、有效等位基因数(Ne)为1.192 3～1.407 9,以上数据表明朱砂根居群遗传多样性较丰富。居群间的遗传变异(Dst)为0.059 2,小于居群内遗传变异(Hs)。居群间的基因流为1.4335(1),具有较高的基因流动。不同居群的遗传一致度于0.6201～0.9782之间,遗传距离于0.024 2～0.559范围内,证明了朱砂根各居群间的亲缘关系接近。对遗传距离与地理距离进行Mantel相关性分析发现无显著相关性。通过对朱砂根各居群样株进行主坐标分析,发现居群间亲缘关系远近和地理分布规律无较明显的相关性,但居群间基因流动较密切,且具备一定程度的遗传分化,并依据Structure遗传结构分析,把居群划分为两大类的结果与主坐标分析相似,且居群间存在较高的遗传渗透。本研究为今后构建朱砂根资源核心种质库,优良性状种源的筛选与储存、引种及驯化及种群保护策略的制定及新资源的开发提供相关的理论依据。     

贵州旱稻种质资源的SSR遗传多样性分析

本研究利用24对水稻微卫星（SSR）标记对源自贵州部分县乡种植以及早期基因库收集的112份地方旱稻材料的遗传多样性进行分析,结果共检出187个等位基因,每个位点的等位基因变幅为4～13个,平均Nei＇s基因多样性指数为0.6431,平均香农指数为1.3669。籼粳亚种均具有较高的遗传多样性,前者稍高于后者,但差异不明显。黔西南州拥有最多的种质,存在丰富的遗传变异,是贵州旱稻种质资源遗传多样性分布中心。分子方差分析表明,旱稻种质总变异的88%是由各地区内的群体间差异造成,地区间和各个群体内的遗传变异较小,均为6%。不同地区旱稻种质的遗传分化程度不一,变幅为2%～18%。聚类分析将供试旱稻材料较为明显地分为籼粳两个类群,而地理分组不明显。     

基于SSR分子标记的野生山胡椒(Lindera glauca)核心种质的构建

为深入发掘和筛选中国野生山胡椒种质资源,本研究利用18对SSR引物(5叶绿体SSR和13核SSR),以基本涵盖中国大陆自然分布区的22个自然群体共303份野生山胡椒种质为材料,进行SSR基因分型分析,并绘制出原始种质的亲缘关系图。结果表明,18对引物共检测到Na=88,Ne为1.18～3.76,He为0.14～0.74,Ho为0～0.58,I为0.30～1.52,以及PIC为0.13～0.70。STRUCTURE分析和UPGMA聚类的结果都显示出22个自然群体适合被划分为三个亚类群。利用等位基因最大化(M策略)和遗传距离最大化(SAGD)法分别至少要在25%(71份种质)、15%取样比例下(45份种质)构建的核心种质才能够在所有遗传多样性指标上代表原始种质的遗传多样性(t检验不显著),并符合核心种质构建的标准。结合核心种质构建工作的同类研究,确定SAGD法(15%取样比例)是较适宜于构建山胡椒核心种质的方法。基于nSSR标记,SAGD法15%比例下构建的核心种质在Na、Ne和I指标参数上的保留率分别达到了原始种质的93.24%、104.67%和100.85%;基于cpSSR标记,与之对应的保留率分别为85.14%、107.45%和108.82%。通过此法筛选出的45份核心种质材料能够一定程度地代表中国整个野生山胡椒种质资源的遗传多样性。研究结果可为其他对非作物型木本植物的核心种质构建,尤其是兼有无性与有性繁殖的物种提供参考。     

DNA profiling and genetic diversity of Korean soybean (<Emphasis Type="Italic">Glycine max</Emphasis> (L.) Merrill) landraces by SSR markers

Approximately 7,000 accessions of Korean soybean (Glycine max (L.) Merrill) landraces, largely composed of three collections, the Korea Atomic Energy Research Institute’s soybean (KAS), the Korean Crop Experiment Station’s soybean (KLS) and the Korean Agricultural Development and Technology Center’s soybean (KADTC) collections, have been conserved at the Rural Development Administration (RDA) genebank in Korea. The accessions within collections were classified based on their traditional uses such as sauce soybean (SA), sprouted soybean (SP), soybean for cooking with rice (SCR), and OTHERS. A total of 2,758 accessions of Korean soybean landraces were used to profile and to evaluate genetic structure using six SSR loci. A total of 110 alleles were revealed by at the six SSR loci. The number of alleles per SSR locus ranged from 9 to 39 in Satt187 and Satt_074, respectively. The number of alleles ranged from 87 in the KADTC collection to 96 in the KLS collection, and from 63 in the SCR group to 95 in the SP group. Nei’s average genetic diversity ranged from 0.68 to 0.70 across three collections, and 0.64 to 0.69 across the usage groups. The average between-group differentiation (G _st) was 0.9 among collections, and 4.1 among the usage groups. The similar average diversity among three collections implies that the genetic background of the three collections was quite similar or that there were a large number of duplicate accessions in three collections. The selection from the four groups classified based upon usage may be a useful way to select accessions for developing a Korean soybean landrace core collection at the RDA genebank. DNA profile information of accessions will provide indications of redundancies or omissions and aid in managing the soybean collection held at the RDA genebank. The information on diversity analysis could help to enlarge the genetic diversity of materials in breeding programs and could be used to develop a core collection.     

国外栽培豌豆遗传多样性分析及核心种质构建

从111对备选SSR引物中筛选出能扩增出清晰稳定单一带的多态性引物21对及其最佳退火温度, 并优化了豌豆SSR标记实验体系。利用上述引物, 对来自于67个国家的731份豌豆栽培种质(Pisum sativum L.)进行遗传多样性分析与核心种质构建。共扩增出109条多态性带, 每对引物平均扩增出5.19个等位变异。SSR等位变异在各大洲间分布不均匀, 有效等位变异数、Shannon’s信息指数(I)洲际间差异明显。各大洲资源群间遗传多样性差异显著, 其中亚洲最高(I = 1.1753), 欧洲其次(I = 1.1387), 俄罗斯联邦(I = 1.0285)、美洲(I = 1.0196)、非洲(I = 0.9254)、大洋洲(I = 0.8608)依次降低。利用Popgene 1.32软件, 依豌豆栽培资源洲际间Nei78遗传距离可聚类成2个组群和4个亚组群; 基于Structure 2.2软件分析, 国外栽培豌豆资源实际由3大类群组成, 并与Popgene 1.32聚类结果呼应得较好。上述两种分析方法均表明, 国外栽培豌豆类群的遗传多样性与其地理分布相关。设计并实践了一套基于Structure分析的科学可靠、逻辑性强的核心种质构建标准化方案, 并依此构建了一套以6.57%的资源(48份)涵盖总体84.4%等位变异的国外栽培豌豆核心种质。     

Genetic Diversity of Farmers’Preferred Sorghum Accessions and Improved Lines from ICRISAT Reveal a Disconnect Between Innovation and Technology Transfer

The genetic diversity of 65 accessions of sorghum [Sorghum bicolor (L.) Moench] collected from various farmers and germplasm lines from ICRISAT-Kenya were analyzed. Simple sequence repeats (SSR) markers were used in order to determine the extent and distribution of its genetic diversity. Twenty-nine (29) SSRs markers were polymorphic and a total of 192 alleles were detected which showed diversity. The number of alleles per primer ranged from 2 to 17, with an average of 6.62. The range of polymorphism information content (PIC) ranged from 0.03 to 0.86, with total average of 0.82. According to the results analyzed, estimates of the mean allelic pattern across the two populations was generated; expected heterozygosity (He; 0.45, 0.54), average observed alleles (Na; 3.40, 6.20), number of private allele (0.23, 3.03), and Shannon information index (I; 0.85, 1.13) for farmer and ICRISAT-Kenya germplasm, respectively. The expected heterozygosity (He) varied from 0 to 0.26 with an average of 0.05. The Neighbor-joining phenogram based on Nei’s genetic distance grouped the 65 accessions into three main groups. The analysis of molecular variance (AMOVA) revealed that 99% of the total genetic variation was within accessions in a population whereas the genetic variation among populations in accessions accounted for 1% of the total genetic variation. Genetic diversity in ICRISAT sorghum material compared to the farmer’s collection suggested little infiltration of improved germplasm to the farmers.     

Genetic diversity in red clover (Trifolium pratense L.) revealed by morphological and microsatellite (SSR) markers

The NPGS-USDA core collection with 85 accessions of red clover, an important forage species, is little described. The goal of the present study was to evaluate the diversity of a set of accessions from the core collection at the morphological and molecular level in order to extract some valuable accessions for Brazilian red clover breeding programs. Twenty-one morphological traits, collected in field and greenhouse in South Brazil, and seven SSR markers were used to describe 57 accessions from the U.S. core collection and one population cultivated in Southern Brazil. Variation between accessions was large for most of the 21 morphological traits. A cluster analysis based on the morphological traits revealed five distinct clusters that separated the populations according to flowering earliness, as already described, but also according to persistency, growth habit and dry matter productivity. Over seven SSR loci, the number of alleles averaged 11.1 alleles per locus. Genetic diversity measured with SSR markers was high, with a mean expected heterozygosity of 0.86. An analysis of molecular variance revealed that the largest proportion of variation (83.6%) resided at the within population level. Although the molecular markers also separated accessions into five clusters, there was no coincidence between the composition of groups found with morphological and molecular data. Use of genetic diversity in breeding programs requires to use the most promising populations, to combine positive traits such as persistency and forage yield, and probably to use within population variation to detect valuable genotypes that could be used as parents of synthetic varieties.     

野生榆叶梅遗传多样性的AFLP分析

本研究利用AFLP分子标记技术,对野生榆叶梅6个居群进行分析.利用已筛选出的8对引物组合进行扩增,共产生256条谱带,其中206条谱带具有遗传多态性,占总谱带的80.47％;平均每对引物组合扩增产生129条多态条带,平均多态率为50.26％.6个居群观察等位基因数Na平均值为1.502 6,总Na值为1.804 7;有...     

中国花生小核心种质与ICRISAT微核心种质的SSR遗传多样性比较

明确花生种质资源的遗传多样性和分布规律,对于发掘优良种质资源,选配优良亲本,拓宽育成品种的遗传基础具有重要意义。核心种质为种质资源的研究、评价和鉴定带来了方便。本研究从206对SSR引物中筛选26对引物对我国花生小核心种质和ICRISAT微核心种质共466份资源进行了遗传多样性分析,相似系数为0.49～0.99,鉴定出遗传差异最大的种质L2刚果(中国花生资源)与ICG12625(ICRISAT资源),相似系数为0.49。分析结果表明,多粒型花生的多态性信息量(0.761)和遗传多样性指数(0.97～1.11)均最大(平均相似系数最小,0.73～0.76),其次是普通型花生。中国花生种质资源与ICRISAT资源存在较大差异,尤其是ICRISAT的赤道型材料ICG12625,与中国花生资源的差异最大。相似系数和遗传多样性指数的分析结果均表明,我国花生种质资源的遗传多样性比ICRISAT资源丰富。     

Population structure and linkage disequilibrium of ICRISAT foxtail millet (Setaria italica (L.) P. Beauv.) core collection

Use of diverse germplasm is a key factor which allows high level of resolution due to extensive recombination in the history. Therefore, population used in association mapping should posses as many phenotypes as possible. One of the methods to obtain most of the phenotypes is to construct the core collection. The ICRISAT foxtail millet core collection consisting of 155 accessions was genotyped using 72 simple sequence repeat (SSR) markers to investigate the genetic diversity, population structure and linkage disequilibrium (LD). A high degree of molecular diversity among the accessions was found, with an average of 16.69 alleles per locus. STRUCTURE analyses classify the accessions into four subpopulations (SP) based on SSR allelic diversity. The Neighbor joining clustering and the principal coordinate analysis were in accordance with the racial classification. The distribution of molecular genetic variation among and within the four SP and three races showed high degree of variability within each group, and low level of genetic distance (GD) among the groups. LD decay of <40 cM of GD in foxtail millet core collection was observed, which suggests that it could be possible to achieve resolution down to the 40 cM level. From this investigation, it is evident that the foxtail millet core collection developed at ICRISAT is very diverse and could be a valuable resource for trait association mapping, crop breeding and germplasm management.     

裸燕麦品质资源AFLP标记遗传多样性分析

用20对AFLP引物组合对281份栽培裸燕麦(Avena nuda)进行遗传多样性分析,共得到1 137条带,其中260条为多态性带,引物的平均多态性百分率为22.96%,平均多样性信息指数(PIC)为0.0326。以地理来源分组,不同来源的组群Simpson指数在1.235~1.495之间,Shannon指数范围为0.1558~0.4437,组群内变异贡献率为83.45%,组群间变异占16.55%。组群大小与多态性位点数、组群内变异贡献率、Simpson指数及Shannon指数显著相关。内蒙古和山西资源多样性丰富,东北地区资源独特,西部地区资源遗传结构单一,东欧组群与内蒙古组群遗传关系最近。国内组群的遗传多样性水平高于国外组群。地方品种与育成品种相比,组群内变异贡献率较高。建议在遗传多样性丰富地区进一步收集裸燕麦资源,并加强对材料少、代表性较差的地区,如西北和西南地区的裸燕麦地方品种的收集,以丰富我国的裸燕麦基因源。     

采用AFLP和SSR标记对扁蓿豆遗传多样性进行比较分析

为了筛选出优异的扁蓿豆育种新材料,本研究采用AFLP和SSR分子标记技术对来自于中国7个省市自治区的15份扁蓿豆种质资源进行遗传多样性的比较分析,结果表明:18对SSR引物扩增出109个多态位点,8个AFLP引物组合扩增出640条带,其中472条多态带.AFLP标记的平均Nei′s遗传多样性指数、Shannon多样性指数和遗传分化系数均高于SSR标记.15份扁蓿豆种质的遗传距离和遗传相似系数与地理类群很接近.AFLP和SSR数据的聚类分析显示:15份扁蓿豆种质分为4大类,但是聚类结果与地理类群不完全相符,主成分结果与聚类结果相似,Mantel 检测表明:AFLP和SSR数据有较高的显著相关性,AFLP和SSR标记能够有效地对扁蓿豆进行遗传多样性分析,其结果为扁蓿豆育种和资源保护具有指导意义.