基于SSR分子标记的延胡索遗传多样性研究

采用SSR分子标记分析延胡索的遗传多样性,筛选出多态性高、稳定性好的12对引物,对19个居群360份延胡索样品进行了群体遗传分析。结果表明:(1)12对SSR引物共扩增出多态性位点227个,检测到4~9个等位基因,平均等位基因数目为5.25个,表现出丰富的多态性;延胡索居群具有较高的遗传多样性(Na=5.25,I=1.192 6,H=0.387 9),物种间遗传分化程度高(Fst=0.388 3),基因流较弱(Nm=0.393 8)。(2)UPGMA聚类分析和贝叶斯距离分析结果表明,19个居群明显聚为4大支;Mantle Test结果(r=0.326,P=0.01)表明,地理位置相近的种群亲缘关系更近。研究认为,延胡索的遗传结构是该物种自交为主的繁育系统、克隆生长、地理隔离以及居群间有限的基因流共同作用的结果,故对该物种的保护应以就地保护为主。     

基于SSR标记的荔枝种质遗传多样性分析

从53对本课题组自主开发设计的SSR特异引物对中筛选出22对多态性引物,对46份荔枝材料的基因组DNA进行扩增,共得到54个等位基因,其中每对引物的平均等位基因数为2.4,共获得23个特异性标记,各标记的平均观察杂合度值、平均期望杂合度和PIC值分别为0.451、0.355和0.507。其中L it6位点各数值最高,是最理想的选择标记。利用22对多态性引物对46份荔枝种质进行聚类分析,构建树状图,结果表明:大多数种质相似系数在0.63～0.95之间,说明它们之间的亲缘关系较近,并发现淮枝(广东)与淮枝(海南)两者可能为同名异物品种。     

我国西南地区玉米地方品种遗传多样性的SSR分子标记分析

利用微卫星(SSR)标记技术和DNA混合取样方法,选取均匀覆盖玉米染色体组的42对SSR引物,检测了来自我国西南地区54个玉米地方品种的遗传多样性。在54个玉米地方品种中检测到256个等位基因,每个SSR标记的等位基因数为2～9个,平均6.1个,说明我国西南地区玉米地方品种遗传多样性丰富。根据遗传相似系数矩阵做出的树状图,将54个玉米地方品种大致划分成4类,来源于同一地区的多数玉米地方品种划分在同一类中,表明西南地区玉米地方品种的地理分布与其遗传背景存在内在联系。从54个玉米地方品种中选出11个,每个品种选取15个单株,共165个DNA单株样品,分析玉米地方品种的遗传结构及其品种内的遗传多样性。对于检测玉米地方品种的遗传多样性,DNA单株样品分析优于DNA混合样品分析,42对相同的SSR引物在11个玉米地方品种中检测到330个等位基因,平均等位基因数A=7.86,有效等位基因数Ae=3.90,平均期望杂合度He=0.69,实际观察杂合度H0=0.37。据遗传结构分析结果,固定指数(F)为0.25～0.79,表明玉米地方品种是典型的混合繁育系统;由于杂合体不足,玉米地方品种群体间及群体内的遗传结构均偏离了Hardy-Weinberg平衡;杂合性基因多样度比率(Fst)平均为0.07,表明品种间和品种内的遗传变异分别占总遗传变异的7%和93%。玉米地方品种内遗传多样性及品种间遗传距离分析结果表明,在我国西南地区,分布在四川的玉米地方品种具有最丰富的遗传变异。经综合分析推测,我国西南地区玉米地方品种最早引进到四川种植,由此向毗邻地区传播扩散。     

水稻SSR标记的遗传多样性研究进展

本文从SSR标记优点和适用于研究水稻遗传多样性入手,综述了SSR标记在水稻核心种质构建与评价、遗传结构、稻种起源演化等方面的研究进展。总结了水稻遗传多样性的地带性特征（云南是中国稻种资源的最大遗传多样性中心和优异种质的富集地;西南稻区粳稻品种遗传多样性最丰富;南方稻区粳稻品种的遗传多样性高于北方粳稻遗传多样性）、遗传多样性与生态地理位置密切相关、目前水稻品种遗传基础狭窄、多样性降低等特征,分析了遗传多样性成因及影响因素,特别指出了育种行为对遗传多样性的影响,并针对当前水稻品种遗传多样性较低的问题提出了对策。     

利用SSR分子标记分析秦岭冷杉自然居群的遗传多样性

利用10对SSR引物对濒危植物秦岭冷杉(Abies chensiensis)6个自然居群的120个个体进行了遗传多样性研究,旨在分析秦岭冷杉6个自然居群的遗传多样性、遗传结构及基因流变化.研究结果表明,120个个体在10个位点上共检测到149个等位基因,平均每个位点的等位基因数(A)为14.9,每个位点的有效等位基因数(e)为7.7,每个位点的平均预期杂合度(He)和平均观察杂合度(Ho)分别为0.841和0.243,Shannon多样性指数(Ⅰ)为2.13,自然居群杂合性基因多样度的比率(FsT)为6.7％,居群间的基因流(Nm)为3.45.利用Mantel检测到自然居群的遗传距离与地理距离间无显著相关性(r=0.490 6,P＞0.05).秦岭冷杉自然居群的遗传多样性水平较低,遗传变异主要存在于居群内部.结合研究数据、实地调查及相关资料,推测秦岭冷杉自然居群间基因流较原来增大可能是因为居群间发生了远交衰退.     

基于SSR分子标记的芋种遗传多样性分析

本研究利用SSR分子标记对来自于国家种质武汉水生蔬菜资源圃的110份芋种资源进行了遗传多样性分析.10对SSR引物在110份芋种资源中共扩增得到40条带,多态性百分率为100％,Shannon信息指数范围为0.390 5～1.426 8,反映了这110份芋种资源的遗传多样性程度较高.110份芋种资源遗传相似系数介于0.43～1,在遗传相似系数0.63处,聚类图将其分为6个类群.该研究结果为芋种资源的保护和利用奠定了基础.     

30个粳稻品种SSR标记遗传多样性分析

选用分布于水稻12条染色体上的64对SSR引物,对江苏省育成以及日本引进的粳稻品种共30份材料进行遗传多样性分析。结果表明,有50对SSR引物在30个品种间表现为多态性。共检测到140个等位基因,每对引物的等位基因数变幅为2～5个,平均为2．8个。有效等位基因为94．336个,平均为1．887。每个SSR位点的多态性信息量（PIC）变化范围为0．064～0．752,平均为0．410。30个品种间的遗传相似系数变幅为0．386～0．956之间,平均值为0．719,且81．4％的供试品种其遗传相似系数在0．600～0．800之间,亲缘关系较近;以遗传相似系数为原始数据,按UPGMA方法将30个品种划分为3大类群,结合系谱分析结果表明,江苏省育成的水稻品种遗传多样性不够丰富,多数品种间的亲缘关系较近,欲进一步提高江苏省水稻产量还需拓宽亲本选择范围,扩大遗传背景。     

山杨杂种无性系的SSR分子标记遗传多样性

采用5对SSR引物对52个山杨杂种无性系进行了遗传多样性检测,结果表明在研究的5个位点上SSR标记多态位点百分率为100%,平均等位基因数为4.4个,有效等位基因数最多的位点是PTR7,最少的位点为PTR12;欧美山杨杂种的遗传多样性最丰富,相比之下,中美山杨杂种遗传变异最低;聚类分析表明,在一定的遗传距离基础上,欧美山杨杂种和欧洲山杨首先聚为一类,然后又与中美山杨杂种聚类,最后是中国山杨。研究表明来自芬欧美山杨杂种具有较高的遗传多样性,这对我国山杨遗传资源的扩大,以及未来山杨杂交育种,杂种优势的利用都是重要的。     

河北省冬小麦品种SSR标记遗传多样性分析

利用79对多态性较高的SSR引物,对河北省1997-2007年间审定的冬小麦品种及国家小麦区试抗旱对照品种晋麦47和洛旱2号,共计87个冬小麦品种进行遗传多样性分析。79对SSR引物共检测出175个等位变异位点,每对引物可产生1~6条等位变异位点,平均2.215条。标记位点多态性信息含量(PIC)变幅为0.824~0.998,平均为0.941;有效等位基因数(Ne)变幅为1.644~20.333,平均4.708;香农指数(H’)变幅为0.148~1.102,平均为0.544,说明河北省冬小麦品种SSR遗传多样性较低。品种间遗传相似系数(GS)变幅为0.184~0.899,平均为0.418,其中河农826与石家庄8号间的遗传相似性最高,GS高达0.899,71-3与藁优9618间的遗传相似性最低,GS为0.184。不同育种单位培育的小麦品种平均遗传相似系数存在较大差异。UPGMA遗传相似性聚类表明,石家庄市小麦新品种新技术研究所培育的小麦品种与其他单位品种存在较大的遗传差异。     

利用SSR标记分析海南普通野生稻的遗传多样性

选用平均分布于水稻基因组的28对SSR引物,对海南不同纬度5个普通野生稻居群的163份材料进行遗传多样性和遗传结构研究。结果表明:(1)海南普通野生稻具有较高的遗传多样性,28个位点共检测到227个等位变异,平均等位变异数A=8.1071,有效等位变异数Ae=4.4190,平均期望杂合度He=0.4004,实际观察杂合度Ho=0.7062,香农指数I=1.6048;(2)居群的遗传分化系数较大,总的遗传变异中有46.40%存在于居群间(Fst=0.4640);(3)居群内杂合体较高(F is=-0.7069),根据固定指数(F=0.0588)计算出的异交率t=0.8889,说明海南普通野生稻的繁育系统属于一种较高的异交混合交配类型。     

利用氟乐灵进行同源四倍体萝卜种质创制研究

本研究应用除草剂氟乐灵处理两叶一心幼苗生长点,进行同源四倍体萝卜种质诱导,对变异植株进行形态、细胞学鉴定和花粉母细胞染色体数目鉴定。结果表明,应用 0.2 mmol/L 和 1.0 mmol/L 氟乐灵处理,6个萝卜品种都获得同源四倍体植株,10 mmol/L 处理仅在 Nau-zhqh 得到同源四倍体;其中 0.2 mmol/L处理 Nau-dy 和 1.0 mmol/L 处理 Nau-xbch 获得四倍体最高诱导率(40%);四倍体种质与二倍体种质相比,形态性状、气孔大小、保卫细胞内叶绿体数目、花器官大小、花粉粒大小及花粉萌发率都存在显著差异,将形态、气孔鉴定和染色体计数结合可以准确确定变异株的倍性。研究表明利用氟乐灵诱导是进行萝卜同源四倍体种质创新的有效途径之一。本研究应用除草剂氟乐灵处理两叶一心幼苗生长点,进行同源四倍体萝卜种质诱导,对变异植株进行形态、细胞学鉴定和花粉母细胞染色体数目鉴定。结果表明,应用 0.2 mmol/L 和 1.0 mmol/L 氟乐灵处理,6个萝卜品种都获得同源四倍体植株,10 mmol/L 处理仅在 Nau-zhqh 得到同源四倍体;其中 0.2 mmol/L处理 Nau-dy 和 1.0 mmol/L 处理 Nau-xbch 获得四倍体最高诱导率(40%);四倍体种质与二倍体种质相比,形态性状、气孔大小、保卫细胞内叶绿体数目、花器官大小、花粉粒大小及花粉萌发率都存在显著差异,将形态、气孔鉴定和染色体计数结合可以准确确定变异株的倍性。研究表明利用氟乐灵诱导是进行萝卜同源四倍体种质创新的有效途径之一。     

Genetic Diversity of Radish (Raphanus sativus L.) Germplasm Resources Revealed by AFLP and RAPD Markers

Genetic diversity of 56 radish accessions, representing nearly all the typical types and origins of cultivated radish germplasms conserved in the National Mid-term Genebank for Vegetables of China, was assessed with amplified fragment length polymorphism (AFLP) and random amplified polymorphic DNA (RAPD) markers. A total of 72 and 128 polymorphic bands were generated by the 12 selected RAPD primers and eight AFLP primer combinations respectively. A moderate correlation with the value of r = 0.66 was observed between AFLP and RAPD markers. The total 200 polymorphic bands were integrated to assess the genetic diversity of 56 radish accessions. The Jaccard similarity coefficients between the accessions varied from 0.30 to 0.83 with the mean of 0.54. Cluster analysis classified the germplasms into three groups of var. hortensis Becker, var. sativus, and var. niger Kerner. The three-dimensions scatter plot of principle coordinate analysis (PCA) further divided var. hortensis Becker germplasms into two separate groups. The results indicated that the genetic diversity harbored among var. hortensis Becker germplasms was very abundant, which could be further exploited for radish genetic improvement.     

Draft Sequences of the Radish (Raphanus sativus L.) Genome

Radish (Raphanus sativus L., n = 9) is one of the major vegetables in Asia. Since the genomes of Brassica and related species including radish underwent genome rearrangement, it is quite difficult to perform functional analysis based on the reported genomic sequence of Brassica rapa. Therefore, we performed genome sequencing of radish. Short reads of genomic sequences of 191.1 Gb were obtained by next-generation sequencing (NGS) for a radish inbred line, and 76,592 scaffolds of ≥300 bp were constructed along with the bacterial artificial chromosome-end sequences. Finally, the whole draft genomic sequence of 402 Mb spanning 75.9% of the estimated genomic size and containing 61,572 predicted genes was obtained. Subsequently, 221 single nucleotide polymorphism markers and 768 PCR-RFLP markers were used together with the 746 markers produced in our previous study for the construction of a linkage map. The map was combined further with another radish linkage map constructed mainly with expressed sequence tag-simple sequence repeat markers into a high-density integrated map of 1,166 cM with 2,553 DNA markers. A total of 1,345 scaffolds were assigned to the linkage map, spanning 116.0 Mb. Bulked PCR products amplified by 2,880 primer pairs were sequenced by NGS, and SNPs in eight inbred lines were identified.     

Analysis of genetic relationship on Amygdalus mira (koehne) Ricker with other peach species using simple sequence repeat (SSR)

Amygdalus mira (Koehne) Ricker is native to China and has many good economical traits. However, its genetic diversity information has not been extensively studied. In this study, to assess the genetic diversity and relationships of A. mira and other peach species (nineteen accessions from Zhengzhou, Henan Province and seven accessions from Harbin) we used simple sequence repeat (SSR) markers. Here, 10 SSR primers were used, and 100% of the SSR primers were polymorphic, with an average of 5.5 alleles per primer pairs, suggesting that these primers were informative for this study. Additionally, polymorphism information content (PIC) value ranged from 0.82 to 0.96 with an average of 0.91. All the accessions were clustered into two groups (cluster 1 and cluster 2) based on SSR data. Principal coordinate analysis recovered similar results that all accessions were divided into two major clusters. The genetic variations within and among populations were 63.9% and 36.1%, respectively. In conclusion, A. mira maintains high genetic variation levels. This research will be potentially useful to aid breeding and enhance the economic and ornamental value of this wild peach.     

Genetic Diversity Analysis of Nelumbo Accessions Based on EST SSR Markers

EST-SSR markers were applied to estimate the genetic diversity for 30 accessions of Nelumbo nucifera, 6 accessions of Nelumbo lutea and 14 hybrids between these two species. The 52 of 123 EST SSR markers (423%) were screened and then applied to amplify the 50 Nelumbo accessions. A total of 177 alleles were identified, and the number of alleles per locus and Polymorphic Information Content (PIC) value varied from 2 to 8 with an average of 34 alleles and from 063 (NNFB 1059) to 091 (NNFB 750) with an average value of 079, respectively. Jaccard similarity coefficients of the amplification results were analyzed by NTSYS pc2.11 software and the genetic similarity coefficient was from 024 to 086. The clustering dendrogram constructed by UPGMA method indicated that 50 accessions of Nelumbo could be divided into four major groups at the similarity coefficient of 037. Group I and group II included Nnucifera; group III included the majority of Asian American lotus hybrids; and group IV included Nlutea. In addition, the Asian American hybrids were closer to Nnucifera based on genetic relationship, which is consistent with the traditional classification result and the previous reports.     

Arabinogalactan-Proteins from Primary and Mature Roots of Radish (Raphanus sativus L.)

Organ-specific variations in blood group H-like activity were observed in developing radish plants. A temporary increase in serological activity was found to occur in the roots at the earlier stages of development. Arabinogalactan-proteins (AGPs) were isolated from primary and mature roots, and investigated for changes in their physicochemical properties, structure, and serological activities. These root AGPs were composed mainly of l-arabinose and d-galactose but were distinguishable from each other in their contents of l-fucose as well as of protein and hydroxyproline. The structures of the carbohydrate moieties of the root AGPs were essentially similar to those of AGPs isolated from seeds and mature leaves in that they consisted of consecutive (1→3)-linked β-d-galactosyl backbone chains having side chains of (1→6)-linked β-d-galactosyl residues, to which α-l-arabinofuranosyl residues were attached in the outer regions. One prominent feature of the primary root AGPs was that they contained appreciable amounts of l-fucose, which was presumably responsible for expression of the serological activity. In their immunological reactions with rabbit anti-radish leaf AGP antibody, the root AGPs were shown to share common antigenic determinant(s) with those of seed and leaf AGPs.     

山西省榛属植物居群的SSR遗传多样性研究

利用9对SSR引物对山西省平榛(Corylus heterophylla Fisch)和毛榛(C.mandshurica Maxim.et Rupr.)野生居群、欧榛(C.avellana L.)和平欧杂种榛(C.heterophylla Fisch.×C.avellana L.)的人工栽培居群,共205个样本进行PCR扩增,共扩增出172个等位基因。每个位点的等位基因数为5~18个,平均等位基因数为12.5个。居群观测杂合度(Ho)和预期杂合度(He)的变化范围分别为0.395~0.665和0.778~0.906,表明榛属植物遗传多样性较高,其中平欧杂种榛的遗传多样性最高(He=0.867,I=2.271),毛榛遗传多样性最低(He=0.825,I=2.006)。不同物种居群间遗传分化系数FST=0.106,平均基因流Nm=2.609,表明居群间的遗传分化水平较低。各居群在大多数位点上偏离Hardy-Weinberg平衡,主要原因是人工选择或近交所致。分子方差分析(AMOVA)表明,遗传变异主要发生在物种居群内。NJ聚类结果显示毛榛和平榛多数个体聚在各自居群内,平欧杂种榛和欧榛个体交互混合组成一小支后再与平榛聚在一起,表明平欧杂种榛与欧榛、平榛的亲缘关系较近,而毛榛与其它3种榛属植物的亲缘关系较远。本研究还分析讨论了山西省榛属植物居群具有较高遗传多样性的原因,并提出了野生榛子的保护利用策略。     

Acylated anthocyanins from red radish (Raphanus sativus L.)

Twelve acylated anthocyanins were isolated from the red radish (Raphanus sativus L.) and their structures were determined by spectroscopic analyses. Six of these were identified as pelargonidin 3-O-[6-O-(E)-feruloyl-2-O-beta-D-glucopyranosyl]-(1-->2)-beta-D-glucopyranoside]-5-O-(beta-D-glucopyranoside), pelargonidin 3-O-[6-O-(E)-caffeoyl-2-O-(6-(E)-feruloyl-beta-D-glucopyranosyl)-(1-->2)-beta-D-glucopyranoside]-5-O-(beta-D-glucopyranoside), pelargonidin 3-O-[6-O-(E)-p-coumaroyl-2-O-(6-(E)-caffeoyl-beta-D-glucopyranosyl)-(1-->2)-beta-D-glucopyranoside]-5-O-(beta-D-glucopyranoside), pelargonidin 3-O-[6-O-(E)-feruloyl-2-O-(6-(E)-caffeoyl-beta-D-glucopyranosyl)-(1-->2)-beta-D-glucopyranoside]-5-O-(beta-D-glucopyranoside), pelargonidin 3-O-[6-O-(E)-p-coumaroyl-2-O-(6-(E)-feruloyl-beta-D-glucopyranosyl)-(1-->2)-beta-D-glucopyranoside]-5-O-(beta-D-glucopyranoside), and pelargonidin 3-O-[6-O-(E)-feruloyl-2-O-(2-(E)-feruloyl-beta-D-glucopyranosyl)-(1-->2)-beta-D-glucopyranoside]-5-O-(beta-D-glucopyranoside).