水稻高代回交导入系群体产量相关性状的QTL定位及抽穗期基因DTH6的鉴定

发布时间：2019-05-17 20:44

【摘要】：水稻的高产稳产对保障我国粮食安全具有重要意义。近年来,品种遗传基础趋于狭窄已成为水稻产量潜力进一步提高的瓶颈。江苏为粳稻生产大省,挖掘可供粳稻品种选育应用的产量相关QTL/基因,拓宽现有品种的遗传基础对提高粳稻品种的产量潜力及江苏省粮食生产均具有重要的意义。本研究构建了一套以优质中籼品种黄华占为供体,改良迟熟中粳品种武育粳3号而来的新品系抗条武育粳3号为背景的高代回交导入系群体,多年考察导入系产量相关性状;同时利用简化基因组重测序技术(SLAF-seq)对导入系进行测序分析,明确各株系中导入片段。结合性状考察及重测序数据对产量相关性状进行QTL定位研究,并对已克隆的重要产量基因Gn1a在直立穗粳稻遗传背景下的效应进行全面分析,同时对新的QTL/基因进行定位,相关结果为产量相关性状的分子育种和新基因的定位克隆奠定基础。具体结果如下:(1)采用性状优先的方法构建了一套包含210个株系的高代回交导入系群体,根据系谱及SLAF-seq测序结果,选择133份高代回交导入系材料(56个BC4F4及77个BC3F5),于2014年和2015年对这133份材料16个产量相关性状进行考察。(2)利用简化基因组重测序(SLAF-seq)获得244,683个SLAF标签,其中有效多态性标签25,784个,有效多态性达10.54%。从有效多态性标签中最终筛出10,103个高质量SLAF标签用于后续分析,均匀分布于12条染色体上,其中第2染色体最多,共1,328个标签,最少的是第12染色体,共296个标签。(3)利用高质量SLAF标签对应的SNP分型,结合两年环境下16个产量相关性状考察数据,在QTL IciMapping V4.0软件中共定位到120个产量相关性状QTLs。与水稻播始天数、株高、单株穗数、单株产量、穗长、一次枝梗数、一次颖花数、二次枝梗数、二次颖花数、主茎穗颖花数、结实率、千粒重、粒长、粒宽、粒厚、长宽比相关的QTLs分别为11、6、4、6、3、11、9、4、5、6、6、12、3、12、13和9个,其中两年能重复检测到18个QTLs;两年分别定位到但距离相近、遗传效应方向一致,可视为同一 QTL的共12个;同时控制两个及以上性状的QTL簇有6处。(4)在直立穗粳稻遗传背景下,Gn1a能显著增加二次枝梗数、二次枝梗颖花数及穗长、一次枝梗数、一次枝梗颖花数和穗总粒数,但单株穗数显著减少,单株产量未见显著提高;在籽粒性状上表现粒宽显著增加、长/宽比减小的特点,有千粒重提高、垩白粒率增加的趋势。要利用Gn1a基因增加穗粒数来提高直立穗粳稻品种的单产,还需聚合其它产量相关基因,以克服单株穗数减少、外观品质变劣的不利影响。(5)利用高代回交导入系T1与抗条武育粳3号配制的F2群体,在位于第6染色体上约500 kb的区间初定位到一个新的抽穗期显性基因DTH6,来源于印度籼型常规水稻Dualr。扬州正季长日照下,携带DTH6株系提早抽穗,而扬州和海南两地抽穗期稳定在82天左右,表明DTH6可减弱株系的感光性。
[Abstract]:The high and stable yield of rice is of great significance to ensure the food security of our country. In recent years, the genetic basis of rice varieties tends to narrow has become the bottleneck of further improvement of rice yield potential. Jiangsu is a major japonica rice production province. It is of great significance to excavate the yield related QTL/ gene which can be used in japonica rice variety breeding and application, and to broaden the genetic basis of existing varieties in order to improve the yield potential of japonica rice varieties and grain production in Jiangsu Province. In this study, a set of high generation backcross introduced lines with high quality medium indica variety Huang Hua Zhan as donor and improved late maturing medium japonica variety Wuyujing 3 as background was constructed, and the yield related characters of introduced lines were investigated for many years. At the same time, the simplified genome resequencing technique (SLAF-seq) was used to sequence the introduced lines, and the imported fragments were identified. Combined with character investigation and resequencing data, the QTL mapping of yield-related traits was carried out, and the effects of cloned important yield gene Gn1a on the genetic background of vertical panicle japonica rice were analyzed comprehensively, and the new QTL/ gene was mapped at the same time. The related results laid a foundation for molecular breeding of yield-related traits and mapping and cloning of new genes. The results are as follows: (1) A set of high generation backcross lines with 210 lines was constructed by character first method. According to the results of pedigree and SLAF-seq sequencing, 133 high generation backcross lines (56 BC4F4 and 77 BC3F5) were selected. Sixteen yield-related traits of the 133 materials were investigated in 2014 and 2015. (2) 244683 SLAF tags were obtained by simplified genome resequencing (SLAF-seq), of which 25784 were effective polymorphism tags, and the effective polymorphism was 10.54%. 10103 high quality SLAF tags were screened out from the effective polymorphism tags for subsequent analysis, which were evenly distributed on 12 chromosomes, of which the second chromosome was the most, with a total of 1328 tags, and the least was chromosome 12. A total of 296 tags. (3) using the SNP typing corresponding to high quality SLAF tags, combined with the investigation data of 16 yield related traits in two years, a total of 120 yield related traits QTLs. were mapped in QTL IciMapping v4.0 software. The number of spikelets per plant, the yield per plant, the length of panicle, the number of primary branches, the number of primary spikelets, the number of secondary branches, the number of secondary spikelets, the number of spikelets per panicle of the main stem, the seed setting rate, 1000-grain weight, grain length, grain width, grain thickness, The QTLs related to aspect ratio was 11, 6, 4, 6, 3, 11, 9, 4, 5, 6, 12, 3, 12, 13 and 9, respectively, of which 18 QTLs; could be repeatedly detected in two years. It was located in two years, but the distance was similar, and the direction of genetic effect was the same, which could be regarded as 12 of the same QTL. There were 6 QTL clusters controlling two or more traits at the same time. (4) under the genetic background of vertical panicle japonica rice, Gn1a could significantly increase the number of secondary branch pedicels, the number of secondary branch spikelets and panicle length, the number of primary branches, the number of primary branch spikelets and the total number of grains per panicle. However, the number of panicles per plant decreased significantly, and the yield per plant did not increase significantly. In grain traits, grain width increased significantly, length / width ratio decreased, 1000-grain weight increased and chalky grain rate increased. In order to increase the grain number per panicle by using Gn1a gene to increase the unit yield of vertical panicle japonica rice varieties, it is also necessary to aggregate other yield related genes in order to overcome the decrease of panicle number per plant. The adverse effects of poor appearance quality. (5) using F2 population prepared by high generation backcross introduction line T1 and resistant Wuyujing 3, a new dominant gene DTH6, at heading stage was initially located in the interval of about 500 kb on chromosome 6. (5) A new dominant gene at heading stage was located in F2 population prepared by high generation backcross introduction line T1 and resistant Wuyujing 3. From India Indica conventional Rice Dualr. Under the long sunshine of Yangzhou season, the lines carrying DTH6 heading early, while the heading date of Yangzhou and Hainan stabilized at about 82 days, indicating that DTH6 could weaken the photosensity of the lines.
【学位授予单位】：扬州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S511

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