【作者】 于拴仓；

【导师】 王永健； 郑晓鹰； 许勇；

【作者基本信息】 中国农业科学院 ， 蔬菜学， 2003， 博士

【摘要】 大白菜（Brassica.campestris L.ssp.pekinensis）原产我国，是我国栽培面积最大的蔬菜作物，构建一张较高密度的永久分子遗传图谱将具有重大意义。本研究利用不同生态型的结球白菜栽培种高代自交系177和276杂交配制杂交组合，通过单粒传代的方法获得102份F₆重组自交系。以此重组自交系（RIL）群体为作图群体，通过AFLP和RAPD两种分子标记的遗传分析，构建大白菜分子遗传图谱并进行重要农艺性状的QTL定位研究。 RIL群体中，AFLP和RAPD标记均出现较高比例的偏分离，两种标记偏分离比例接近。分子标记的分离分析发现，来源于两个亲本的标记座位在群体中的分离比例接近；每个位点上，两个亲本基因频率的平均值比较接近，并没有发现群体有偏向某一亲本的现象。表明该群体总体上未出现严重的偏分离。 利用AFLP和RAPD两种分子标记构建了包含17个连锁群，由352个遗传标记组成的大白菜连锁图谱，其中包括265个AFLP标记和87个RAPD标记，图谱覆盖基因组2665.7cM，平均图距7.6cM。每个连锁群上的标记数在6～43之间，平均图距在3.4～13.0cM之间，连锁群长度在20.3～400.7cM范围内。连锁群上有13.92％的分子标记出现偏分离，偏分离标记在连锁群上聚集出现。该图谱是国内第一张结球白菜分子遗传图谱，将为基因定位、比较基因组学和重要农艺性状的QTL定位等研究打下良好基础。 采用复合区间作图的方法对控制大白菜耐热性的数量性状基因位点进行定位和遗传效应研究。用苗期热害指数进行耐热性表型鉴定，共检测到5个耐热性QTL，分布于3个连锁群上。5个QTL中，3个表现为增效加性效应，2个表现为减效加性效应。5个QTL的遗传贡献率在7.00％～18.53％之间，ht-2对大白菜耐热性的遗传贡献率最大，可能为主效基因位点。 采用复合区间作图的方法对大白菜叶球相关的8个农艺性状进行QTL定位及遗传效应研究。在16个连锁群上定位了8个叶球相关性状的44个QTL，每个性状3-11个QTL，其加性效应各不相等，各位点的遗传贡献率介于4.72％～21.04％之间，其 大白菜分子遗传图谱构建及重要农艺性状的QTL定位2 中控制生育期的QTL有3个，控制外叶数的QTL有3个，控制球高的OTL有7个， 控制球径的OTL有5个，控制球形指数的QTL有11个，控制球叶数的QTL有4个， 控制球重的QTL有4个，控制荒重的OTL有7个。 采用复合区间作图的方法对大白菜9个形态性状进行OTL定位及遗传效应研 究。在14个连锁群上检d到9个形态性状勺50个叮L，每个性刁4－7个叮L；其 加性效应各不相等，各位点的遗传贡献率介于 5．17％－21．50％之间。其中控制株型 的QTL有5个，控制株高的叮L有6个；控制开展度的QTL有5个，控制最大叶长 白OTL有7个，控制最大叶宽的QTL有4个，控制叶形指数的gTL 有6个，控制中 肋长的叮L有7个，控制中肋宽的叮L有4个，控制抽墨性的叮L有6个。更多还原

【Abstract】 To Chinese cabbage, the most important economic crop, it is more meaningful to construct a molecular genetic map. A population of Fe generation including 102 recombinant inbred lines was derived from the cross of two advanced lines 177 and 276 of cultivated Chinese cabbage (Brassica. campestris L. ssp. pekinensis), using single seed descendant method. In this paper, the AFLP and RAPD markers were employed in constructing a molecular genetic map and mapping QTL controlling heat tolerance and some agronomically important traits in Chinese cabbage.In this RIL population, Distorted segregation is a universal phenomenal, and the frequency of distorted segregation markers was similar for AFLP or RAPD. Out of 492 markers, the number of markers came from male parent and female parent agrees with the Mendel ratio 1:1. To single marker, the frequency of band from two parents was closely, and not deflected to either parent. It could be concluded that no obvious distorted segregation in the population.A molecular genetic map of Chinese cabbage was constructed using AFLP and RAPD markers. 352 markers including 265 AFLP markers and 87 RAPD markers were integrated into 17 linkage groups. It covered a total of 2665.7 cM with an average interval of 7.6 cM. Number of markers in linkage groups varied from 6 to 43, average interval distance from 3.4 cM to 13.0 cM and the total map distance from 20.3 to 400.7cM. A total of 13.92% distorted markers distributed in the map. The molecular genetic map is fundamental for gene localization, comparative genomics, and QTL mapping of agronomically important traits.Composite interval mapping method was employed in mapping and analysis QTL controlling heat tolerance and some important agronomical traits in Chinese cabbage.These results will provide useful information for molecular assistant selection of some important agronomic traits in breeding programmes of Chinese cabbage.Heat damage index in seedlings was used as phenotypic value to detect QTL cntrolling heat tolerane in Chinese cabbage. Five putative QTL were mapped in three linkage groups. Three loci including ht-\, ht-3 and ht-5 showed positive additive effect, while ht-2 and ht-4 showed negative additive effect. Phenotypic variation explained by the putative QTL varied from 7.00% to 18.53%. ht-2 had the highest contribution to heat tolerance, and it may be a major gene locus.Forty-four QTL controlling agronomic traits related to head were mapped on 16 linkage groups. These QTL included three for days to harvesting, three for number of non-wrapper leaves, seven for head length, five for head diameter, eleven for head length /head diameter ratio, four for number of head-forming leaves, seven for head weight and seven for gross weight There was unequal gene effects on the expression of many agronomic traits related to head, and the variation explained ranged from 4.72% to 21.04%.The number, location, variation explained and additive effect of QTL underlying nine morphological traits were also determined. Fifty putative QTL, including five for plant growth habit, six for plant height, five for plant diameter, seven for leaf length, four for leaf width, six for leaf length/leaf width ratio, seven for petiole length, four for petiole width and six for bolting character, were mapped on 14 linkage groups. There was unequal gene effects on the expression of many morphological traits, and the variation explained ranged from 5.17% to 21.50%.更多还原