甘蓝型油菜花瓣缺失基因的图谱定位

在无花瓣品系APT02和正常有花瓣品种中双4号构建的的F2分离群体中,运用AFLP和SRAP两种标记技术对甘蓝型油菜花瓣缺失基因进行分子标记和图谱定位。在两亲本间筛选20对AFLP引物和170对SRAP 引物,进一步通过BSA法筛选,获得了与甘蓝型油菜花瓣缺失基因WHB连锁的1个SRAP标记e8m3_4（600bp）和1个AFLP标记E3247_15（150bp）,标记与基因WHB之间的遗传距离分别为5 cM和13.5cM;构建了一个甘蓝型油菜(Brassica napus.L )的分子标记遗传连锁图谱,该图谱共包含213个AFLP标记、56个SRAP标记和1个形态标记,分布于17个主要连锁群、两个三联体和4个连锁对中,遗传图距总长2487.1cM,标记间平均距离为10.09 cM。通过图谱定位,控制花瓣缺失性状的基因WHB被定位到第4连锁群(LG4)上。     

大粒裸燕麦(Avena nuda L.)遗传连锁图谱的构建

以“元莜麦”和“555”杂交得到的281个F2单株为作图群体,利用20对AFLP引物、3对SSR引物和1个穗型性状构建了一张大粒裸燕麦遗传连锁图。该图谱全长1544.8cM,包含19个连锁群,其上分布有92个AFLP标记、3个SSR标记和1个穗型形态标记,不同连锁群标记数为2-14个,长度在23.7-276.3cM之间,平均长度为81.3cM,标记间平均距离为20.1cM。穗型标记分离比符合3：1,11个AFLP标记表现为偏分离,偏分离比为11.5%。该图谱符合遗传连锁框架图的要求,为今后大粒裸燕麦的QTL定位、分子标记辅助育种和比较基因组学等研究奠定基础。     

甘蓝型油菜千粒重性状的QTL初步定位研究

千粒重是油菜重要的产量相关性状之一,构建油菜遗传连锁图谱是研究其产量性状基因的前提。本研究利用小孢子培养技术,选育出了甘蓝型油菜大粒品系(G-42)和小粒品系(7-9)的纯合DH系DH-G-42和DH-7-9,其千粒重分别为6.24 g和2.42 g,二者比值达2.58。以DH-G-42为母本、DH-7-9为父本,构建了含190个单株的F2遗传作图群体,利用SSR和SRAP标记技术绘制遗传连锁图谱,该图谱共包含20个连锁群,涉及128个SSR标记和100个SRAP标记,图谱总长1546.6cM,标记间平均图距为6.78cM。本研究共检测到3个与千粒重性状相关的QTL,分别位于A9和C1连锁群,其中qSW-A9-1和qSW-A9-2贡献率分别达到10.98%和27.45%,均可视为控制粒重的主效QTL。本研究为后续进行油菜千粒重性状QTL的精细定位分析、分子标记辅助选择育种及新基因的克隆等奠定了基础。     

甘蓝型油菜分子标记连锁图谱的构建及显性细胞核雄性不育基因的图谱定位

在显性细胞核雄性不育系Rs1046A和双低油菜品种Samourai构建的回交分离群体中,运用AFLP和SSR两种标记技术构建了一个甘蓝型油菜(Brassica napus L.)的分子标记遗传连锁图谱。该图谱共包含138个AFL．P标记、83个SSR标记和1个形态标记,分布于18个主要连锁群、2个三联体和1个连锁对上,图谱总长度为2646cM,偏分离标记的比例为11．7％。显性细胞核雄性不育基因Ms被定位到第10连锁群(LG10)上。同时,偏分离标记聚集于第8连锁群(LG8)和第16连锁群(LGl6)的末端,形成了十分明显的偏分离标记密集区域。研究结果对于油菜核不育两型系的分子标记辅助选择育种具有重要意义,同时也为克隆和分离核不育基因以及研究核不育的分子机理打下了良好的基础。     

大豆遗传图谱的构建和分析

利用大豆栽培品种科丰1号和南农1138－2杂交得到的重组近交系NJRIKY,通过RFLP,SSR,RAPD和AFLP4种分子标记的遗传连锁分析,构建了包含24个连锁群,由792个遗传标记组成的大豆较高密度连锁图谱,该图谱覆盖2320．7cM,平均图距2．9cM,SSR标记的多态性较高,在基因组中的位置相对稳定,可以作为锚定标记,有利于连锁群的归并和不同图谱的比较整合;而AFLP标记对于增加图谱密度效率较高,但其容易出现聚集现象,从而造成连锁群上有很大的空隙（gap),另外,在连锁群中有21．7％的分子标记出现偏分离,该图谱为基因定位,比较基因组学和重要农艺性状的QTL定位等研究打下了基础。     

梨分子遗传图谱构建及生长性状的QTL分析

利用鸭梨和京白梨杂交得到的F1(145株)实生苗为作图群体,通过对AFLP和SSR两种分子标记的遗传连锁分析,应用Joinmap 3.0作图软件,368个AFLP标记、34个SSR标记构建了分属18个连锁群的梨分子遗传连锁图谱,各连锁群的LOD值在4.0～7.0范围之间,图谱总长度覆盖梨基因组1395.9cM,平均图距为3.8cM.采用区间作图法,对该群体与生长性状相关的调查数据进行QTL分析,检测到与新梢生长量、新梢茎粗、节间长度、节间数量、树干径、树高及皮孔密度7个农艺性状连锁的QTL位点35个,其中主效QTL位点11个(LOD≥3.5).与生长性状相关的农艺性状QTL位点多集中在LG16连锁群上.     

''百农64''×''京双16''小麦遗传连锁图谱构建

通过对小麦品种‘百农64’ב京双16’F3家系群体的SSR和AFLP分析,构建了含100个SSR标记(91个引物)和58个AFLP标记(12个引物)的小麦遗传连锁图,158个标记组成20个连锁群,覆盖小麦基因组3 114cM,标记间平均间距为19.7 cM.将前人未定位的12个SSR标记定位到了小麦遗传连锁图谱上.为小麦慢白粉病性等农艺性状的QTL分析打下了良好基础.     

甘蓝型油菜遗传图谱的构建及单株产量构成因素的QTL分析

采用常规品系04-1139与高产多角果品系05-1054构建的F2代群体为作图群体, 运用SSR(Simple sequence repeat)和SRAP(Sequence-related amplified polymorphism)构建分子标记遗传图谱并对甘蓝型油菜单株产量构成因素进行QTL分析。遗传图谱包含200个分子标记, 分布于19个连锁群上, 总长度1 700.23 cM, 标记间的平均距离8.50 cM。采用复合区间作图法(Composite interval mapping, CIM)对单株产量构成因素(单株有效角果数、每果粒数和千粒重)进行QTL分析, 共检测到12个QTL: 其中单株有效角果数4个QTL, 分别解释表型变异为35.64%、12.96%、28.71%和34.02%; 每果粒数获得5个QTL, 分别解释表型变异为8.41%、7.87%、24.37%、8.57%和14.31%; 千粒重获得３个QTL, 分别解释表型变异为2.33%、1.81%和1.86%。结果表明: 同一性状的等位基因增效作用可以同时来自高值亲本和低值亲本; 文章中与主效QTL连锁的标记可用于油菜产量性状的分子标记辅助选择和聚合育种。     

南瓜遗传连锁图谱的构建及粒宽性状的QTL定位

以印度南瓜纯系大粒材料‘0515-1’和小粒材料‘0460-1-1’为亲本,获得193个南瓜F2单株群体,应用AFLP和SSR分子标记技术进行多态性筛选,构建了含84个标记位点的遗传连锁图谱。结果表明,整个图谱包含12个连锁群,全长683.50cM,标记平均间距为8.13cM。采用复合区间定位分析,共检测到控制南瓜籽粒宽度的4个数量性状位点(QTL),分别位于3个连锁群上,各QTL的贡献率在2.87%～29.68%之间。     

利用向日葵重组自交系构建遗传图谱

以向日葵自选系K55为母本、K58为父本杂交组合,通过单粒传得到的187个F_5：6代重组自交系群体为作图材料,联合应用SSR和AFLP标记构建遗传连锁图谱。经过78对SSR引物和48对AFLP引物组合选择性扩增,分别得到341和1119条带,共1460条,分别获得多态性条带184条和393条,共577条多态性条带,占所有条带的39.52%。SSR和AFLP标记各有84个和108个多态性标记偏离孟德尔分离比例(P=0.05),共192个偏分离标记。采用JoinMap4.0软件进行连锁分析,构建了1张总长度为2759.4 cM、包含17个连锁群、连锁495个多态性标记的遗传图谱,其中偏分离标记170个,标记间的平均图距为5.57 cM。每个连锁群上分布有5~72个标记,长68.88~250.17 cM。本图谱为向日葵永久性图谱,为向日葵重要性状QTL定位和基因克隆奠定基础。     

QTL Mapping of Seed Coat Color for Yellow Seeded Brassica napus

The development of yellow-seeded varieties of Brassica napus for improving the oilseed quality characteristics of lower fiber content and higher protein and oil content has been a major focus of breeding researches worldwide in recent years. With the black-seeded ‘Youyan 2’ as male and the yellow-seeded GH₀₆ as female parents respectively, F₂ population of 132 individuals were obtained. A linkage map was constructed with 164 markers including 125 AFLP, 37 SSR, 1 RAPD and 1 SCAR markers distributed over 19 linkage groups covering approximately 2 549.8 cM with an average spacing of 15.55 cM. Two loci located on the 5th and 19th group were detected for the trait of seed coat color based on the linkage group using multiple interval mapping method and explained 46% and 30.9% of the phenotypic variation, respectively.     

Refined mapping of the Pierce’s disease resistance locus, PdR1, and Sex on an extended genetic map of Vitis rupestris × V. arizonica

A framework genetic map based on genomic DNA-derived SSR, EST-derived SSR, EST-STS and EST-RFLP markers was developed using 181 genotypes generated from D8909-15 (female) × F8909-17 (male), the ‘9621’ population. Both parents are half siblings with a common female parent, Vitis rupestris ‘A. de Serres’, and different male parents (forms of V. arizonica). A total of 542 markers were tested, and 237 of them were polymorphic for the female and male parents. The female map was developed with 159 mapped markers covering 865.0 cM with an average marker distance of 5.4 cM in 18 linkage groups. The male map was constructed with 158 mapped molecular markers covering 1055.0 cM with an average distance of 6.7 cM in 19 linkage groups. The consensus ‘9621’ map covered 1154.0 cM with 210 mapped molecular markers in 19 linkage groups, with average distance of 5.5 cM. Ninety-four of the 210 markers on the consensus map were new. The ‘Sex’ expression locus segregated as single major gene was mapped to linkage group 2 on the consensus and the male map. PdR1, a major gene for resistance to Pierce’s disease, caused by the bacterium Xylella fastidiosa, was mapped to the linkage group 14 between markers VMCNg3h8 and VVIN64, located 4.3 and 2.7 cM away from PdR1, respectively. Differences in segregation distortion of markers were also compared between parents, and three clusters of skewed markers were observed on linkage groups 6, 7 and 14.     

大豆重组自交系群体（ZKS-HX）遗传图谱的构建和形态标记的定位

以大豆品种‘合丰25’为母本,半野生大豆‘新民6号’为父本杂交得到的F2-9代122个重组自交系为试验材料,构建了含有124个SSR标记、1个EST标记、3个形态学标记的大豆遗传图谱。此图谱覆盖的基因组长度为2348．3cM．标记间平均距离为18．3cM。每个连锁群长度范围为15．1～195．9cM之间,标记数范围2—10个。本文将控制茸毛色（Pb）基因定位于LG06-C2连锁群上,与Sat_40x2的遗传距离为39．6cM;控制叶耳g（Le）、花色（4W,）基因定位于LG12-F连锁群上,它们之间的遗传距离为9．9cM,与两边的Satt348、Sat_240标记遗传距离分别为13．3cM和10．5cM。     

Genetic linkage maps of two apricot cultivars ( Prunus armeniaca L.), and mapping of PPV (sharka) resistance

Genetic linkage maps for two apricot cultivars have been constructed using AFLP, RAPD, RFLP and SSR markers in 81 F1 individuals from the cross 'Goldrich' x 'Valenciano'. This family segregated for resistance to 'plum pox virus' (PPV), the most-important virus affecting Prunus species. Of the 160 RAPD arbitrary primers screened a total of 44 were selected. Sixty one polymorphic RAPD markers were scored on the mapping population: 30 heterozygous in 'Goldrich', 19 heterozygous in 'Valenciano', segregating 1:1, and 12 markers heterozygous in both parents, segregating 3:1. A total of 33 and 19 RAPD markers were mapped on the 'Goldrich' and 'Valenciano' maps respectively. Forteen primer combinations were used for AFLPs and all of them detected polymorphism. Ninety five markers segregating 1:1 were identified, of which 62 were heterozygous in the female parent 'Goldrich' and 33 in the male parent 'Valenciano'. Forty five markers were present in both parents and segregated 3:1. A total of 82 and 48 AFLP markers were mapped on the 'Goldrich' and 'Valenciano' maps. Twelve RFLPs probes were screened in the population, resulting in five loci segregating in the family, one locus heterozygous for 'Valenciano' and four heterozygous for both, segregating 1:2:1. Of the 45 SSRs screened 17 segregated in the mapping family, resulting in seven loci heterozygous for the maternal parent and ten heterozygous for both, segregating 1:2:1 or 1:1:1:1. A total of 16 and 13 co-dominant markers were mapped in the female and male parent maps respectively. A total of 132 markers were placed into eight linkage groups on the 'Goldrich' map, defining 511 cM of the total map-length. The average distance between adjacent markers was 3.9 cM. A total of 80 markers were placed into seven linkage groups on the 'Valenciano' map, defining 467.2 cM of the total map-distance, with an average interval of 5.8 cM between adjacent markers. Thirty six marker loci heterozygous in both parents revealed straightforward homologies between five linkage groups in both maps. The sharka resistance trait mapped on linkage group 2. The region containing sharka resistance is flanked by two co-dominant markers that will be used for targeted SSR development employing a recently constructed complete apricot BAC library. SSRs tightly linked to sharka resistance will facilitate MAS in breeding for resistance in apricot.     

Genetic analysis of floral anthocyanin pigmentation traits in Asiatic hybrid lily using molecular linkage maps

To understand the genetic background of two floral anthocyanin pigmentation traits, anthocyanin pigmentation in the flower tepals and spot formation, in the Asiatic hybrid lily (2n = 24), segregation of the two traits among 96 F₁ plants derived from a cross between commercial cultivars 'Montreux' and 'Connecticut King' were investigated. 'Montreux' has anthocyanin pigmentation in the tepals with many spots, and 'Connecticut King' has flowers with carotenoid pigmentation without spots. The F₁ plants with or without anthocyanin pigment in the tepals segregated with a 1:1 segregation ratio, indicating that a single gene controls anthocyanin pigmentation in the tepals. The number of spots per square centimeter of all tepals showed continuous distribution in the F₁ plants. To map the loci for the two anthocyanin pigmentation traits, molecular linkage maps in the Asiatic hybrid lily were constructed using a double pseudo-testcross strategy, with the same F₁ plants used for phenotypic evaluation, and 212 PCR-based DNA markers. The trait for anthocyanin pigmentation in tepals was used as a trait marker. The map of 'Montreux' comprised 95 markers in 26 linkage groups, and the map of 'Connecticut King' used 119 markers in 24 linkage groups. The total map lengths were 867.5 and 1,114.8 cM, respectively. The trait locus for anthocyanin pigmentation in the tepals was between markers ASR35-180 and P506-40 in linkage group 1 of the 'Montreux' map with a map distance of 1.2 cM and 2.6 cM, respectively. A single-point analysis of quantitative trait loci (QTLs) for tepal spot number identified two putative QTLs in linkage groups 1 and 19 of the 'Connecticut King' map. One putative QTL in linkage group 19 explained 64% of the total phenotypic variation. Because both putative QTLs were mapped on the linkage map of 'Connecticut King' that has no spots, dominant alleles of them might suppress spot formation.     

Construction of a High-Density Microsatellite Genetic Linkage Map and Mapping of Sexual and Growth-Related Traits in Half-Smooth Tongue Sole (Cynoglossus semilaevis)

High-density genetic linkage maps of half-smooth tongue sole were developed with 1007 microsatellite markers, two SCAR markers and an F1 family containing 94. The female map was composed of 828 markers in 21 linkage groups, covering a total of 1447.3 cM, with an average interval 1.83 cM between markers. The male map consisted of 794 markers in 21 linkage groups, spanning 1497.5 cM, with an average interval of 1.96 cM. The female and male maps had 812 and 785 unique positions, respectively. The genome length of half-smooth tongue sole was estimated to be 1527.7 cM for the females and 1582.1 cM for the males. Based on estimations of the map lengths, the female and male maps covered 94.74 and 94.65% of the genome, respectively. The consensus map was composed of 1007 microsatellite markers and two SCAR markers in 21 linkage groups, covering a total of 1624 cM with an average interval of 1.67 cM. Furthermore, 159 sex-linked SSR markers were identified. Five sex-linked microsatellite markers were confirmed in their association with sex in a large number of individuals selected from different families. These sex-linked markers were mapped on the female map LG1f with zero recombination. Two QTLs that were identified for body weight, designated as We-1 and We-2, accounted for 26.39% and 10.60% of the phenotypic variation. Two QTLs for body width, designated Wi-1 and Wi-2, were mapped in LG4f and accounted for 14.33% and 12.83% of the phenotypic variation, respectively. Seven sex-related loci were mapped in LG1f, LG14f and LG1m by CIM, accounting for 12.5–25.2% of the trait variation. The results should prove to be very useful for improving growth traits using molecular MAS.     

Genetic linkage map of the interspecific grape rootstock cross Ramsey (Vitis champinii) × Riparia Gloire (Vitis riparia)

The first genetic linkage map of grape derived from rootstock parents was constructed using 188 progeny from a cross of Ramsey (Vitis champinii) × Riparia Gloire (V. riparia). Of 354 simple sequence repeat markers tested, 205 were polymorphic for at least one parent, and 57.6% were fully informative. Maps of Ramsey, Riparia Gloire, and the F1 population were created using JoinMap software, following a pseudotestcross strategy. The set of 205 SSRs allowed for the identification of all 19 Vitis linkage groups (2n=38), with a total combined map length of 1,304.7 cM, averaging 6.8 cM between markers. The maternal map consists of 172 markers aligned into 19 linkage groups (1,244.9 cM) while 126 markers on the paternal map cover 18 linkage groups (1,095.5 cM). The expected genome coverage is over 92%. Segregation distortion occurred in the Ramsey, Riparia Gloire, and consensus maps for 10, 13, and 16% of the markers, respectively. These distorted markers clustered primarily on the linkage groups 3, 5, 14 and 17. No genome-wide difference in recombination rate was observed between Ramsey and Riparia Gloire based on 315 common marker intervals. Fifty-four new Vitis-EST-derived SSR markers were mapped, and were distributed evenly across the genome on 16 of the 19 linkage groups. These dense linkage maps of two phenotypically diverse North American Vitis species are valuable tools for studying the genetics of many rootstock traits including nematode resistance, lime and salt tolerance, and ability to induce vigor.     

Tagging and mapping of rice sheath blight resistant gene

Sheath blight (Rhizoctonia solani Kühn) is one of the severe rice diseases worldwide. In this study, an F(2) population from a cross between "4011" and "Xiangzaoxian19" is used to identify molecular markers linked with the resistant trait. "4011" was a transgenic rice cultivar carrying a resistant gene to sheath blight, while "Xiangzaoxian19" is a highly susceptible one. As a result, five molecular markers, including three RFLP markers converted from RAPD and AFLP markers, and two SSR markers were identified to link with the sheath blight resistant gene. This dominant resistant gene was named as R sb 1 and mapped on rice chromosome 5. The linkage distance between the markers (E-AT:M-CAC(120), E-AT:M-CTA(230), OPN-16(2000), RM164(320) and RM39(300)) and R sb 1 was 1.6 cM, 9.9 cM, 1.6 cM, 15.2 cM and 1.6 cM, respectively.     

A genetic linkage map of cowpea (Vigna unguiculata) developed from a cross between two inbred, domesticated lines

 We have constructed a genetic linkage map within the cultivated gene pool of cowpea (2n=2x=22) from an F₈ recombinant inbred population (94 individuals) derived from a cross between the inbreds IT84S-2049 and 524B. These breeding lines, developed in Nigeria and California, show contrasting reactions against several pests and diseases and differ in several morphological traits. Parental lines were screened with 332 random RAPD decamers, 74 RFLP probes (bean, cowpea and mung bean genomic DNA clones), and 17 AFLP primer combinations. RAPD primers were twice as efficient as AFLP primers and RFLP probes in detecting polymorphisms in this cross. The map consists of 181 loci, comprising 133 RAPDs, 19 RFLPs, 25 AFLPs, three morphological/classical markers, and a biochemical marker (dehydrin). These markers identified 12 linkage groups spanning 972 cM with an average distance of 6.4 cM between markers. Linkage groups ranged from 3 to 257 cM in length and included from 2 to 41 markers, respectively. A gene for earliness was mapped on linkage group 2. Seed weight showed a significant association with a RAPD marker on linkage group 5. This map should facilitate the identification of markers that “tag” genes for pest and disease resistance and other traits in the cultivated gene pool of cowpea. Received: 16 September 1996 / Accepted: 25 April 1997     

应用重组自交系群体定位大豆抗虫QTL

以大豆组合科丰1号×南农1138-2衍生的重组自交系(RIL)群体为材料构建遗传连锁图谱, 利用软件 Cartographer V.2.5 采用复合区间作图法检测定位大豆抗虫QTL。以斜纹夜蛾幼虫重为抗性指标, 检测到 1 个与抗虫性有关的 QTL, 位于G20-O连锁群上, 其端距离为31.91 cM, 加性效应估计值为0.0408, 对性状变异的解释率为 11.74％; 以蛹重为抗性指标, 检测到 2 个与抗虫性有关的 QTL, 分别位于G8-D1b+W和G17-L连锁群上, 其端距离分别为 14.71 cM和0.01 cM, 加性效应估计值分别为-0.0139和0.0103, 对性状变异的解释率分别为 11.30％和6.36％。