浙江赤霉病抗性不同的大麦地方品种遗传多样性分析

采用SSR标记方法研究了43份对大麦赤霉病有不同抗性的浙江地方品种的遗传多样性。结果显示29对SSR引物在上述品种中共检测到87个等位基因,每对引物等位基因数在2~9之间,平均为3个;平均多态性信息含量（PIC）为0.3509,平均Shannon指数(I)为0.6951,平均Nei’s基因多样性指数(H)为0.4268。品种间的遗传相似系数变幅为0.082~0.986,平均值为0.467。聚类分析将参试品种分为4大类。浙江省地方品种遗传多样性较高,二棱品种的遗传变异明显高于六棱品种;抗和中抗赤霉病品种的遗传变异也较大。聚类结果与品种来源无任何关系;主成分分析结果与聚类分析结果基本一致。     

Development of 18 polymorphic microsatellite DNA markers of Laminaria japonica (Phaeophyceae)

Eighteen polymorphic microsatellite DNA markers were developed for Laminaria japonica, a brown alga cultured intensively in China. These markers are independent from each other and are moderately variable in L. japonica. The number of alleles and gene diversity detected in 53 gametophyte clones representing the varieties of L. japonica cultured once or currently in China range from two to nine and from 0.355 to 0.768, respectively. These markers will certainly facilitate the management and exploitation of the germplasm resource of L. japonica conserved indoor as gametophyte clones and the determination of the genetic diversity of L. japonica naturally distributed.     

微卫星DNA标记技术及其在昆虫学上的应用

微卫星DNA标记作为一种多态性和稳定性高、重复性好、呈共显性的分子遗传标记技术,目前已被广泛应用于昆虫学的研究中。本文介绍了微卫星DNA标记的基本原理和特点,并综述了近年来该技术在昆虫种群遗传结构及分化、生物学特性与习性、遗传图谱的构建、基因定位以及系统发生等领域中的应用。     

应用微卫星标记进行大豆种质多样性和遗传变异性分析

微卫星标记又称ＳＳＲ标记是近年来发展的一种新型的分子标记可有效地进行基因型鉴定,系统谱分析并可估算材料间的遗传距离。用５对ＳＳＲ引物对１５份大豆材料进行扩增,共得到２１条多态性条带。每个ＳＳＲ座位的等侠基因数目为３～＾个,基因多样性范围为０．４３７～０．６６８,对这些材料进行了遗传距离分析。家系分析表明微卫星ＤＮＡ经过多世代的九分裂的后产生了突变,在ＲＩＬ Ｆ８代中有的个体在个别ＳＳＲ等基因的大小     

Microsatellite marker development,mapping and applications in rice genetics and breeding

Microsatellites are simple, tandemly repeated di- to tetra-nucleotide sequence motifs flanked by unique sequences. They are valuable as genetic markers because they are co-dominant, detect high levels of allelic diversity, and are easily and economically assayed by the polymerase chain reaction (PCR). Results from screening a rice genomic library suggest that there are an estimated 5700-10 000 microsatellites in rice, with the relative frequency of different repeats decreasing with increasing size of the motif. A map consisting of 120 microsatellite markers demonstrates that they are well distributed throughout the 12 chromosomes of rice. Five multiple copy primer sequences have been identified that could be mapped to independent chromosomal locations. The current level of genome coverage provided by these simple sequence length polymorphisms (SSLPs) in rice is sufficient to be useful for genotype identification, gene and quantitative trait locus (QTL) analysis, screening of large insert libraries, and marker-assisted selection in breeding. Studies of allelic diversity have documented up to 25 alleles at a single locus in cultivated rice germplasm and provide evidence that amplification in wild relatives of Oryza sativa is generally reliable. The availability of increasing numbers of mapped SSLP markers can be expected to complement existing RFLP and AFLP maps, increasing the power and resolution of genome analysis in rice.     

Resistance against Fusarium Head Blight in Transgenic Wheat Plants Expressing the ScNPR1 gene

Fusarium head blight (FHB) is a severe global wheat disease that may cause severe yield losses, especially during epidemic years. Transforming the regulatory genes in the metabolic pathways of disease resistance into wheat via transgenic methods is one way to improve resistance to FHB. ScNPR1 (Secale cereale‐NPR1), a regulatory gene for systemic acquired resistance (SAR), was isolated from S. cereale cv Jingzhouheimai and transformed into the moderately FHB‐susceptible wheat variety Ningmai 13. RT‐PCR analysis indicated that the ScNPR1 gene was stably expressed in transgenic plants. An evaluation of the resistance to FHB revealed that six ScNPR1 transgenic lines (NP1, NP2, NP3, NP4, NP5 and NP6) exhibited significantly higher FHB resistance than the wild‐type wheat Ningmai 13 and the null‐segregated plants. The expression of pathogenesis‐related (PR) genes after Fusarium graminearum inoculation was earlier or higher than those in the wild‐type variety Ningmai 13. The high expression in the early stages of PR genes should account for the enhanced FHB resistance in the transgenic lines. Our results suggest that overexpression of ScNPR1 could be used to improve FHB resistance in wheat.     

Isolation and characterization of microsatellite markers from the phytopathogenic fungus Alternaria dauci

Eleven polymorphic microsatellite markers were isolated from the necrotrophic phytopathogenic fungus Alternaria dauci based on enriched genomic libraries. In order to assess allelic variability, the microsatellite loci were analysed in a collection of 43 isolates. The number of detected alleles in 11 loci ranged from two to 24 (mean 10.4). Test of cross-species amplification and sequencing of the resulting amplicons showed that some of these microsatellites could be used in different species such as Alternaria solani, Alternaria bataticola and Alternaria zinniae.     

基于SSR分子标记的沙枣遗传多样性分析和指纹图谱构建

为了促进沙枣新品种选育、种质资源鉴定保护和生态经济型沙枣产业综合发展,对沙枣(Elaeagnus angustifolia)种质资源进行遗传多样性分析,构建DNA指纹图谱,挖掘沙枣种质来源和遗传背景。本研究采用多态性好、条带清晰、重复性好的11对引物,利用简单重复序列(simple sequence repeats,SSR)分子标记技术,对甘肃省和北京市来源的150份沙枣材料的遗传多样性进行了研究,基于遗传距离进行非加权组平均法(unweighted pair-group method with arithmetic means,UPGMA)聚类分析,基于贝叶斯模型的Structure v2.3.3软件解析150份种质的遗传结构。在遗传多样性分析中,平均等位基因数为(number of alleles,Na)7.636 4,平均有效等位基因数(number of effective alleles,Ne)为2.832 6,平均Shannon信息指数(Shannon genetic diversity index,I)为1.178 1,Nei’s平均基因多样性指数(Nei’s gene diversity index,H)为0.582 1,平均观测杂合度(observed heterozygosity,Ho)为0.489 9,平均期望杂合度(expected heterozygosity,He)为0.584 0,平均多态信息含量(polymorphism information content,PIC)为0.535 4,平均遗传相似性系数(genetic similarity,GS)为0.831 5,表明所研究的沙枣之间具有显著的遗传差异和丰富的遗传多样性。聚类分析将150份材料划分为3个类群,平均遗传距离(genetic distance,GD)为0.422 9,聚类结果和地理来源并不完全一致。Structure群体结构分析将供试材料分为2个种群。利用8对多态信息含量最高的引物,构建了150份沙枣材料的指纹图谱。本研究成功构建了甘肃和北京沙枣种质资源的DNA指纹图谱,阐明了其亲缘关系,为沙枣种质资源鉴定、优异种质筛选、园林应用和分子辅助育种工作提供了理论依据。     

小麦抗赤霉病研究现状与展望

小麦是我国最重要的口粮作物之一。在小麦生产所面临的各种病害中,赤霉病的发生具有愈来愈严重的趋势,引起小麦产业界的高度关注。近几十年来,科研人员在小麦抗赤霉病遗传育种以及防控技术领域进行了持续不懈的努力,在赤霉病病原菌致病基因、小麦赤霉病抗性基因定位、克隆及功能研究以及抗赤霉病分子育种等方面取得了重大进展。本文主要从赤霉病抗性基因资源的发掘和鉴定、不同抗源遗传基础解析、小麦赤霉病抗性基因、抗赤霉病分子标记辅助选择育种与基因聚合以及小麦抗赤霉病基因的克隆和功能研究等方面进行了综述,分析了目前小麦抗赤霉病研究中存在的问题,并提出应加强基因克隆、功能分子标记开发以及应用单体型辅助选择(HAS)和标记组辅助选择(MSAS)等小麦抗赤霉病研究的相关建议。     

大麦基因组中的微卫星标记及其应用

微卫星是以少数几个核苷酸为单位多次串联重复的DNA序列,是一种简单序列重复(simple sequence repeats,SSR),两侧一般是保守序列。由于它具有多态性高、共显性、容易用PCR检测和结果稳定可靠等特点,因此是一种十分理想的分子标记。大麦的微卫星DNA随机分布于基因组中,平均每一个微卫星基因座有3～18个等位基因,最高可达37个。SSR标记已广泛用于分子遗传图谱的构建、遗传多样性研究、种质鉴定、主要性状基因的定位及分子标记辅助选择育种等。大多数SSR标记集中在着丝粒附近区域,1HL、5HL和6HS明显缺乏SSR标记。大麦的SSR标记还有待进一步的开发。Microsatellite Markers and Applications in the Barley GenomeFENG Zong-yun1,2,3,ZHANG Yi-zheng1,LING Hong-qing31.College of Life Sciences,Sichuan University,Chengdu 610065,China;2.College of Agronomy,Sichuan Agricultural University,Ya'an 625014,China;3.The State Key Laboratory of Plant Cell & Chromosome Engineering,Institute of Genetics & Developmental Biology,Chinese Academy of Sciences,Beijing 100101,ChinaAbstract:Microsatellites,also called simple sequence repeats (SSR),are simple,tandemly repeated DNA sequences with a repeat length of a few base pairs,and are very ideally used as molecular markers because of their abundance,high level of polymorphism,co-dominance and ease of assay with the polymerase chain reaction (PCR) by selecting primers as the conserved DNA sequences flanking the SSRs,as well as better stability.The experiments showed that SSRs are randomly distributed throughout the barley genome,and there are 3~18 alleles at a single SSR locus,up to 37 alleles/locus.SSR markers have being widely applied in the construction of molecular genetic map,the study of genetic diversity,the identification of germplasm,gene mapping for important traits and molecular marker-assisted selection.Meanwhile,most of markers are strongly clustered around the centromeric regions of all seven linkage groups.As a result of the clustering,genome coverage with SSRs remains incomplete with an obvious lack of markers on the long arms of chromosomes 1H and 5H and short arm of chromosome 6H.Therefore,it is very potential and necessary to further develop SSR markers in barley.Key words：barley;microsatellite marker;simple sequence repeats;genetic diversity;molecular mapping     

微卫星DNA标记技术及其在植物研究中的应用

微卫星DNA(或简单重复序列,simplesequencerepeats,SSR)是继RFLP、RAPD等分子标记后出现的第二代分子标记技术。随着分子生物学的发展,微卫星标记技术在植物基因组中的应用越来越广泛。由于SSR具有多态性高,呈共显性遗传,遵守孟德尔式分离,在数量上没有生物学的限制,实验操作简单,对样品质量要求不高等特点,因此被广泛用于植物遗传图谱的构建、基因定位、构建指纹图谱、遗传多样性及物种进化与亲缘关系的研究等方面。     

基于表达序列标签的简单重复序列标记开发策略

作为一种新型分子标记,表达序列标签-简单重复序列(EST-SSR)来自表达基因,因此除具备来源于传统基因组的SSR标记的所有优势外,还与基因功能表达具有直接或间接的关系,从而强化了SSR标记在遗传研究中的应用。我们简要介绍了EST-SSR标记的开发策略、方法及其应用进展,总结了其中存在的一些问题,目的是为今后该领域的研究提供一定的参考。     

巴氏蘑菇微卫星序列的分离及其对Co60辐射诱变菌株的鉴别

根据链霉素磁珠和生物素特异结合的特性,用生物素标记的二聚核苷酸重复序列探针从巴氏蘑菇的基因组中分离微卫星序列。将结合于链霉素磁珠上的标记探针同两端连接已知序列人工接头的巴氏蘑菇DNA酶切片段杂交。洗脱未杂交DNA片段后,用磁珠富集的片段建立微卫星文库。挑取522个菌落用对应重复序列为引物进行PCR筛选,得到48个阳性克隆,经测序有32个菌落含微卫星序列。微卫星富集效率为阳性克隆数的67%,总克隆数的6%。除去重复或无效的微卫星序列,在设计出的12对用于鉴别85个巴氏蘑菇的Co60辐射变异株微卫星引物中,有4对引物总共扩增出明显的变异菌株17个。证明有些微卫星位点可用于巴氏蘑菇辐射变异品种的指纹筛选与鉴别。     

5个籼稻背景的高代回交置换系的置换片段分析

以轮回亲本籼稻品种9311（Oryza sativassp.indica‘Yangdao6’）为对照,选用132个亲本间有多态性的SSR标记,对以粳稻品种日本晴（Oryzasativassp.japonica‘Nipponbare’）为供体的5个高代回交置换系的农艺性状及置换片段进行分析。5个置换系在粒长、粒宽、千粒重、剑叶长、株高及落粒性等方面与籼稻品种9311之间有极显著差异,其余性状与籼稻品种9311间的差异不显著;从置换系中检测出8个置换片段,总长度为236.0cM,平均长度为29.5cM;从置换片段上检出包括2个千粒重、1个粒长、1个粒宽、1个剑叶长、1个株高和1个落粒性共7个QTLs,分别分布在水稻第1、3、5、6和第10染色体上。其中,第1染色体上控制剑叶长的QTL和第6染色体上控制株高的QTL可能是新发现的QTLs。实验结果进一步丰富了置换系群体的数量和质量,也为QTLs的精细定位及分子设计育种奠定了基础。     

黑龙江省主栽大豆品种遗传多样性的SSR分析

使用合丰25等来自13个育种单位的13份大豆（Glycinemax）品种对大豆20个连锁群上的100对SSR标记进行筛选,最终保留了扩增稳定且多态性较高的43对SSR标记,分析了黑龙江省83个主栽大豆品种的遗传多样性。结果表明,在所有供试材料中共鉴定出等位变异157个,每个位点2—7个,平均为3．65个。品种间遗传相似系数为0．216—0．937,平均为0．6384,表明黑龙江省大豆品种的遗传相似性较大,故拓宽黑龙江省大豆品种的遗传基础具有重要意义。