【作者】 高妍；

【导师】 韩明玉；

【作者基本信息】 西北农林科技大学 ， 园艺植物种质资源， 2008， 硕士

【摘要】 桃属于多年生果树植物,由于世代周期长及其高度杂合性,使分子遗传作图不仅在理论上而且在育种实践上有十分重要的意义和价值。目前已发表的桃遗传连锁图谱普遍存在图谱覆盖基因组范围较小(多数图谱仅覆盖基因组范围的50%左右甚至更少),群体数目都比较小,许多图谱特别是国内研究人员构建的桃图谱标记间平均距离较大(﹥10cM),并且许多标记还不能定位在连锁图上。本研究以油桃品种‘秦光2号’和‘曙光’的91株正交F1代个体为试材,利用AFLP分子标记方法和JoinMap○R3.0软件构建桃分子标记连锁图谱。主要研究结果如下:建立了桃成熟叶片高质量基因组DNA提取方法:高质量的基因组DNA是AFLP分析体系的关键步骤,本研究在传统CTAB法的基础上有所改进,所提DNA的纯度和完整性都较好,OD260 nm/OD280 nm的比值均为1.8～2.0,无降解现象, RNA去除干净,能被限制性内切酶完全消化,后续AFLP反应正常,说明此方法提取的桃成熟叶片基因组总DNA完全适于AFLP分析。构建了较高密度桃分子遗传连锁图:利用120对引物组合对亲本进行多态性分析,选择多态性丰富、扩增稳定的37对引物进行群体分离分析,共获得了标记158个,偏分离标记27个,双亲位点符合1:1的比率,总体上未出现严重的偏分离。应用JoinMap○R3.0分析软件的CP作图模型将122个AFLP标记和2个单基因控制的质量性状标记(核黏离性状F/f和黄肉白肉性状Y/y)定位于11个连锁群上,共计有36个标记(包括20个偏分离标记)未能构建在连锁图上。该图谱覆盖桃基因组1034cM,连锁群的平均长度为94cM,每个连锁群包含2～23个标记,标记间平均距离为8.34cM。核黏离性状F/f被定位于连锁图第七连锁群上,与标记TC/CAA(300)相距10cM;黄肉白肉性状Y/y被定位于连锁图第四连锁群上,与标记ACC/CTG(120)相距5.9cM,与标记CT/CTG(370)相距12.6cM。根据标记的作图效率,图谱覆盖程度以及标记密度等方面的分析,本研究所构建的桃分子遗传图谱质量较高,为挖掘桃有益基因打下了基础,为桃分子遗传育种提供了依据,在本研究基础之上适合做进一步的研究。更多还原

【Abstract】 Peach is a kind of the perennial fruit crop. For it’s long period of a generation, molecular genetic mapping is very important theoretically and practically in breeding. At present, the genetic linkage maps of peach that have already been published have some common problems such as the length of covering whole genome is short (most are only 50% or less) and the number of progeny is small, as well as some maps’average distance between adjacent loci are big(>10cM) especially that constructed by Chinese, even some markers can not integrated in maps.A linkage map of AFLPs was obtained using a F1 progency which were derived from a cross between nectarine cultivars‘Qinguang2’and‘Shuguang’with JoinMap○R 3.0 software. The main results as follows:DNA extraction method high-quality from mature leaves of peach was established: The stable and high efficient AFLP analysis system of peach-genome high quality of genome DNA was a critical step for AFLP analysis. Our method was based on the traditional way of CTAB and had some improvement slightly. The results showed: the extracted DNA of mature leaves by this method was pure, integral, the value of D260 nm/D280 nm was 1.80 to 2.0, degradation was nearly free, the RNA was eliminated completely, and suitable for digestion by restriction endonucleases, subsequent AFLP analysis was normal. Therefore this method could be used for extracting ideal DNA samples from mature leaves peach and suitable for AFLP.A higher-density genetic map was constructed: Polymorhism of parents was analysized with 120 pairs of AFLP primers. The selected 37 AFLP primers with rich and steady bands were tested in progeny. 158markers were scored, of which 27markers were skewed segregation. The amounts of locus derived from different parent were equal. No serious skewed segregation occurred. A linkage map was obtained using JoinMap○R 3.0 software’s CP model. The map is composed of 122 AFLPs and two morphological traits(Y/y and F/f)distributed in 11 linkage groups, 36markers(containing 20 markers skewed segregation) were unlinked. The map covers 1034cM of the peach genome. The average length of linkage group is 94cM. Each group contains 2-23 loci, and the average distance between adjacent loci is 8.34. F/f was located in LG7, and linked to marker TC/CAA(300), the linkage distance was 10cM; Y/y was located in LG4 and linked to marker ACC/CTG(120)and CT/CTG(370), the linkage distance were 5.9cM and 12.6.From the mapping efficiency and the map’s covering degree on the genome and the marker density, the linkage map constructed in this study was of enough quality and could be used to further research.更多还原