【作者】 王丹；

【导师】 杨传平；

【作者基本信息】 东北林业大学 ， 林木遗传育种， 2009， 硕士

【摘要】 白桦（Betula platyphylla Suk.）是我国东北与内蒙古林区的先锋树种之一,是优良的阔叶用材树种。为了加速白桦性状,如生长、材质和材性等遗传改良进程,有必要构建白桦遗传图谱并对上述性状进行定位,从而为辅助选择育种奠定基础。为此,本文进行了以下研究:（1）通过对白桦强化种子园内32株白桦纤维长度测定,选择出纤维长度大于均值加1个标准差的个体为父本和纤维长度小于均值减1个标准差的个体为母本进行控制杂交,从而选择80个F₁代进行分子连锁图谱构建。（2）以父母本为材料,从1,200个RAPD引物中筛选出223个多态性引物,从330对SSR引物中筛选出27对多态性引物;利用选择的RAPD和SSR多态性引物,对父母本和80株白桦F1子代扩增,共获得415个RAPD多态位点和70个SSR多态位点。χ²检验表明410个位点符合1:1分离、45个位点符合3:1分离、30个位点属偏分离。（3）“拟测交”分表表明,410个符合1:1分离位点中,203个位点来自父本,有207个位点来自母本。分别利用MapMaker3.0和MapDrawt2.1构建和绘制图谱,父本203个连锁标记构成了16个不同的连锁群（4个以上标记）,6个三联体和8个连锁对,连锁标记覆盖的总图距为1,402.4cM（centimorgan）,平均图距13.1cM;母本207个标记构成了17个连锁群（4个以上标记）,5个三连体和9个连锁对,连锁标记覆盖的总图距为1,440.7cM（centimorgan）,平均图距12.5cM。（4）利用Windows QTL Cart 2.5软件的复合区间作图法对白桦苗期苗高、地径等性状进行全基因组扫描,在LOD≥2.0的条件下,发现2个与苗高相关的QTL、6个与地径相关的QTL。其中,父本连锁群体中定位1个与苗高相关QTL,其加性效应为-5.57、贡献率为9.76%,1个与地径相关QTL,其加性效应为0.04、贡献率为17.54%;母本连锁群体中定位1个与苗高相关的QTL,其加性效应为-6.14、贡献率为12.54%,5个与地径相关的QTL,其加性效应分别为0.03、0.16、0.15、0.05、-0.25,贡献率分别为9.12%、16.01%、16.72%、18.94%、19.84%。更多还原

【Abstract】 The Betula platyphylla Suk.is pioneer and excellent broad-leaved pulp tree in northeast and inner-Mongolia region.To accelerate the gentic inprovement of B.platyphylla complex character,such as grouth、material、quality,it is necessary to construction of a molecular genetic map and locate the charcter,so as to provide a basis for marker assisted selection breeding.Therefor,the study was done in this paper:(1) After measurement fiber length trait(FLT) of 32 individuals from B.platyphylla population in intensive seed orchard,the individual whose fiber length was larger than the mean value plus one standard deviation was selected as paternal,and the individual whose fiber length is smaller than the mean value minus one standard deviation was selected as maternal.Hybridization was carried out under control,and then a molecular genetic linkage map was constructed with 80 F1.(2) Polymorphism of amplified parents was analysized,223 high polymorphic RAPD primers were screened out from 1,200 primers,and 27 pairs of high polymorphic SSR primers were screened out from 330 pairs of primers.Parents and 80 Fl generation were amplified with screened RAPD primers and SSR primers,415 RAPD polymorphic markers and 70 SSR polymorphic markers were obtained.Afterχ~2 text,410 belonged to 1:1 segregating site,and 45 belonged to 3:1 segregating site,others were found distorted from the normal 1:1 ratio.(3) Altogether 410 sites segregating 1:1 were used to construct parent-specific linkage maps with pseudotestcross strategy,including 203 for paternal and 207 for maternal.Linkage maps was estimated and drawn with MapMaker3.0 and Mapdraw Ver.2.0 software, respectively.The linkage maps consisted of 203 marker sites inl6 groups(four or more sites per group),6 triples and 8 pairs for paternal,which covered the map distance about 1,402.4cM (Kosambi units).The average map distance between adjacent markers was 13.1cM,and 207 linked marker site for maternal were mapped onto 17 groups(four or more sites per group),5 triples and 9 pairs,which covered the map distance about l,440.7cM,and the average map distance between adjacent markers was 12.5 cM.(4) Composite interval mapping method of Windows QTL Cartographer V2.5 was used in QTL analysis of B.platyphylla important traits,such as seedling height、girth and so on. With LOD≥2.0,two QTLs affecting plant height were detected,six QTLs affecting plant girth were deteced.One QTL affecting seedling height was detected in paternal linkage populations. Its additive effect was -5.57 and contribution rate was 9.76%to phenotypic variance. Meanwhile one QTL affecting girth was detected with additive effect 0.04 and contribution rate 17.54%to phenotypic variance.One QTL affecting seedling hight was detected in maternal linkage populations with additive effect -6.14 and contribution rate 12.54%to phenotypic variance.Five QTL affecting girth were detected,and their additive effects were 0.03、0.16、0.15、0.05、-0.25 and contribution rates were 9.12%、16.01%、16.72%、18.94%、19.84%to phenotypic variance,respectively.更多还原