香蕉枯萎病菌RAPD分析及4号生理小种的快速检测

 用随机扩增多态性DNA(RAPD)技术,对采自广东、广西的香蕉和粉蕉上的30个香蕉枯萎病菌(Fusarium oxysporum f.sp.cubense)菌株和3个其它尖孢镰刀菌专化型的菌株进行比较及聚类分析。在遗传相似系数0.67时,可将供试菌株划分为3个RAPD群(RGs),其中香蕉枯萎病菌4号生理小种(FOC4)共15个菌株属于RGⅠ,1号生理小种(FOC1)共15个菌株属于RGⅡ,供试的其它尖孢镰刀菌专化型的3个菌株则属于RGⅢ。这说明香蕉枯萎病菌和供试3个其它专化型菌株与致病性间存在明显的相关性。1号生理小种内菌株间的遗传分化大于4号生理小种内菌株间的遗传分化。从90条RAPD随机引物中筛选出2条引物可产生4号生理小种的RAPD标记2个。将这2个RAPD标记电泳切胶回收、克隆及测序,并根据这2个特异片段序列设计SCAR上下游特异引物,通过对30个菌株的PCR扩增检验,其中一个RAPD标记成功地转化为SCAR标记,初步建立了以此为基础的4号生理小种快速检测技术,其检测灵敏度为2 ng新鲜菌丝。对采自不同地区的显症样品、吸芽、室内接种未显症的香蕉苗以及发病的香蕉植株不同部位进行检测,能够准确灵敏地鉴定出4号生理小种,从而为香蕉枯萎病菌的快速检测及防治奠定了基础。同时,快速检测结果发现,田间发病植株果柄的各部位及果实内并没有枯萎病菌的存在。     

Identification of Molecular Markers for a Aphid Resistance Gene in Sorghum and Selective Efficiency Using These Markers

In this study,an F2 segregated population obtained by hybridization between the aphid-sensitive sorghum strain Qiansan and aphid-resistant cultivar Henong 16 was used to establish an aphid-resistant po...     

Development of a SCAR marker linked with a MYMV resistance gene in mungbean (Vigna radiata L. Wilczek)

Yellow mosaic disease (YMD) caused by mungbean yellow mosaic virus (MYMV) is the most important disease of mungbean, causing great yield loss. The present investigation was carried out to study the inheritance and identify molecular markers linked with MYMV resistance gene by using F₁, F₂ and 167 F_2 : 8 recombinant inbred lines (RILs) developed from the cross ‘TM‐99‐37’ (resistant) × Mulmarada (susceptible). The F₁ was susceptible, F₂ segregated in 3S:1R phenotypic ratio and RILs segregated in 1S:1R ratio in the field screening indicating that the MYMV resistance gene is governed by a single recessive gene. Of the 140 RAPD primers, 45 primers showing polymorphism in parents were screened using bulked segregant analysis. Three primers amplified specific polymorphic fragments viz. OPB‐07_600, OPC‐06₁₇₅₀ and OPB‐12₈₂₀. The marker OPB‐07₆₀₀ was more closely linked (6.8 cM) with a MYMV resistance gene as compared to OPC‐06₁₇₅₀ (22.8 cM) and OPB‐12₈₂₀ (25.2 cM). The resistance‐specific fragment OPB‐07₆₀₀ was cloned, sequenced and converted into a sequence‐characterized amplified region (SCAR) marker and validated in twenty genotypes with different genetic backgrounds.     

SCAR标记技术鉴别榆黄蘑品种

为了建立一套基于DNA分子标记技术快速鉴定榆黄蘑菌株的有效方法,本研究通过对生产上常用的16个榆黄蘑菌株进行SRAP多态性分析,从榆黄蘑2号菌株中扩增获得了一个片段长为537bp的特异片段,将其克隆、测序并设计引物,成功转化为稳定的SCAR标记。试验结果表明,利用该特异SCAR标记,能在1d时间内准确鉴定出榆黄蘑2号菌株。由此可见,SCAR分子标记是一种快速、稳定、准确鉴定榆黄蘑菌株的新方法。     

甘蓝型油菜黄籽基因的SCAR标记鉴定和快速检测

将一个甘蓝型黄籽油菜RAPD标记（S1130）发展成显性SCAR标记（SCS1130）。比较SCS1130的三种检测方法，包括测定PCR反应物浓度、PCR板EB直接染色和电泳，结果表明EB直接染色是最简单快速的检测方法，可降低成本、省时。SCS1130的发展为开展甘蓝型黄籽油菜分子标记辅助选择创造条件，将便利和加快其选育。     

感染“中四”小麦条锈菌T4菌系SCAR检测标记的开发

正条锈病是由小麦条锈菌(Puccinia striiformis f.sp.tritici)引起的世界范围内小麦上最重要的病害之一。利用抗病品种是防治该病最经济、有效的措施。但是由于小麦条锈菌的高度变异性,品种抗病性很容易被条锈菌新小种所克服。因此,持续监测条锈菌生理小种的动态变化,及时发现新小种,对     

松材线虫SCAR标记与检测技术

将松材线虫RAPD特异片段OPM05-X2100进行分离、回收,与载体pGEM-TVector连接,转化大肠杆菌并培养,对目标克隆测序。根据测序结果,用Oligo5.0软件设计引物,正向引物为M05F2(5’-CGGGT CATGG CTGGA GGTAT CGT-3’),反向引物为M05R1(5’-TGGCT CAATG GCAAA TCCTT CGTA-3’),成功地将松材线虫特异片段OPM05-X2100通过引物对M05F2/R1转化为SCAR-M05-X600。运用SCAR标记引物M05F2/R对枯死松树体内分离的92份线虫样本的DNA进行标记,并对单条线虫经简易方法提取的DNA进行检测。结果表明:引物组合对所有81份松材线虫株系均扩增出一条600bp的清晰、明亮的条带,而对8份拟松材线虫、1份霍夫曼尼伞滑刃线虫、1份大核滑刃线虫、1份长尾属线虫均无扩增产物。该对引物可以检测单条松材线虫。利用这对特异引物组合可构建松材线虫检测试剂盒,实现对松材线虫的快速检测的目标。     

Characterization of 14 anonymous nuclear loci in Pinus thunbergii and their cross-species transferability

We characterized 14 anonymous nuclear loci from Pinus thunbergii Parl., an important pine species native to Japan. One hundred and twenty-six single nucleotide polymorphisms (SNPs) were identified from these loci, giving a frequency of 1 SNP per 51 bp. Nucleotide diversity (θ) ranged from 1.06 × 10-3 to 11.87 × 10-3, with an average of 4.99 × 10-3. Only one locus (mK45) deviated significantly from the Hardy-Weinberg equilibrium. Thirteen of 14 loci were applicable in other pine species. These loci will be useful for nucleotide variation studies and will provide material for SNP-based marker development in P. thunbergii and related species.     

Development of Strain-specific Primers for a Strain of Gliocladium catenulatum Used in Biological Control

The randomly amplified polymorphic DNA (RAPD) technique was used to develop strain-specific primers for Gliocladium catenulatum strain J1446, which is promising in biological control. One of the primer pairs developed proved to be strain-specific; strain J1446 was differentiated from 16 G. catenulatum strains and six other strains of two Gliocladium species, as well as from Trichoderma virens, and isolates of Nectria spp. and Fusarium spp. Specific primers were also tested with DNA isolated from cucumber leaves, treated or untreated with a solution made from Gliocladium powder. The expected amplification product was produced only from treated leaves. DNA isolated from Gliocladium-treated potato tubers and fungi grown in peat was also used in amplification reactions. Strain-specific primers detected strain J1446 when the amount of DNA was 5pg or more. Some variation between the Gliocladium strains was found by the random amplified microsatellites method (RAMS) and the universally primed polymerase chain reaction method (UP-PCR), but no clear fragments specific to strain J1446 were produced. Cross-blot hybridisation of UP-PCR products differentiated strain J1446 from T. virens, but not from the Gliocladium isolates. The 28S rDNA sequences and -tubulin sequences were identical or very similar in all Gliocladium strains. Thus, it is possible that the Gliocladium strains of the present study are conspecific, which means that a revision in the taxonomy of Gliocladium species may be necessary.     

Codominant-SCAR技术的建立以及在番茄育种中的应用

 结合SCAR标记的原理与多引物PCR技术, 建立了共显性标记技术Codominant-SCAR。利用该技术对12份番茄近等基因系进行了遗传鉴定, 结果表明该方法具有重复性好、迅速、简便、成本低的特点, 可用于番茄和其它作物的分子育种。