【作者】 郭嗣斌；

【导师】 林兴华；

【作者基本信息】 华中农业大学 ， 作物遗传育种， 2009， 博士

【摘要】 水稻（Oryza sativa L.）是世界上最重要的粮食作物之一。野生稻具有丰富的遗传多样性,拥有大量的有利基因,从野生稻中发掘栽培稻已丢失或削弱了的优异基因己成为当前水稻育种和资源研究的热点之一。本研究选用具有抗稻瘟病、白叶枯病、褐飞虱和白背飞虱的小粒野生稻（Oryza minuta Acc No:101133）为供体亲本,以国际水稻所选育的高产、优质的优良品种“IR24”为轮回亲本构建了一套导入系。不仅分析了小粒野生稻与栽培稻种间杂种及回交后代的特征,还利用所构建的高代回交群体,用AB-QTL分析法对12个数量性状进行了QTL定位分析,同时对一个来自于小粒野生稻的抗白叶枯病新基因进行了遗传分析与定位。主要结果归纳如下:1.通过杂交和回交,结合胚拯救获得了小粒野生稻与栽培稻的种间杂种及回交后代。调查了杂种与各回交后代的交配率和染色体数目,表明杂种F₁、BC₁、BC₂和BC₃的交配率分别为5.58%、0.11%、0.37%和1.62%;杂种染色体数目为36,回交后代的染色体数目为24-48。2.运用175对均匀分布的SSR标记对双亲和92份二倍体的BC₃F₁植株进行了分析。小粒野生稻与栽培稻间SSR标记的多态性概率为93.2%;在92份二倍体的BC₃F₁植株中,小粒野生稻渗入片段的数目、长度、总的大小及其所占全基因组的百分数分别为24.1,17.8 cM,438.4 cM和26.2。3.通过田间的接种鉴定,针对8个白叶枯病生理小种,小粒野生稻都表现为高抗,而IR24都表现感病。杂种F₁对8个生理小种全抗,而56份BC₁对每个的生理小种的抗性反应存在差异,并且在BC₁群体中,对部分生理小种出现了抗性分离。同时还评价了所有BC₃F₁植株对水稻白叶枯病的抗性表现。4.通过对BC₄F₁的基因型的分析和BC₄F₂群体农艺性状的的调查,采用AB-QTL分析法对12性状进行了QTL定位。对9个产量相关性状在武昌和海南分别检测到了28个和31个QTL,其中来自于小粒野生稻的有利QTL分别占46.4%和48.4%。在武昌对3个粒型性状检测到了12个QTL,其中有5个QTL来自于小粒野生稻。5.利用一个BC₂F₂群体及其F₃、F₄家系,通过遗传分析和抗谱鉴定发现了一个来自于小粒野生稻的抗白叶枯病新基因,暂命名为Xa31（t）。同时利用SSR标记对Xa31（t）进行了定位分析,初步将其定位于11号染色体的长臂,同标记RM144共分离,在标记RM7654和RM6293之间,与它们的距离分别为1.1 cM和0.66 cM。更多还原

【Abstract】 Cultivated rice （Oryza sativa L.） is one of the most important crops in the world. The wild species are rich in extremely valuable genes and genetic diversity. To search beneficial genes from wild rice which have been lost or weakened in cultivated rice is one of the important researches on rice resources and breeding. In this study, an substitution lines populations derived from Oryza minuta （Acc. No. 101133）, was rich in resistant gene sources, such as resistance to blast blight, bacterial blight （BB）, whitebacked planthopper, and brown planthopper, as a donor, and an indica cultivar IR24 （Oryza sativa L.）, developed by International Rice Research Institute, which had high yield and good quality, as a recipient, was used to identify quantitative trait loci （QTL） associated with 9 yield and its components traits and 3 grain type traits using advanced backcross QTL analysis （AB-QTL）. At the same time, we report the characterization of the interspecific hybrids and the backcross progenies, and a new bacterial blight resistance gene from O. minuta genetic analysis and mapping. The main results were as follows:1. Interspecific hybrids were obtained from the cross of O. sativa L. （IR24） and O. minuta （Acc. No. 101133） with 5.58% crossability, which was 0.11%, 0.37% and 1.62% in the BC₁, BC₂, BC₃ generations, respectively. The chromosome numbers of interspecific hybrid was 36, and that of the backcross progenies were 24 to 48.2. A total of 175 pairs of SSR primers distributed over all 12 chromosomes of cultivated rice, were used to amplify genomic DNA samples prepared from cultivated rice IR24 and wild rice O. minuta （Acc. No. 101133）. Simple sequence repeat markers analysis showed that the polymorphism ratio of SSR bands between IR24 and O. minuta （Acc. No. 101133） was 93.2%. The average donor segment number, length, donor genome size, and percentage of donor genome of 92 BC3F1 plants （2n=24） were 24.1, 17.8 cM, 438.4 cM and 26.2, respectively.3. After inoculation with eight Xoo strains, O. minuta （Acc. No. 101133） showed high resistance to all eight Xoo strains （lesion lengths less than 1.0 cm）, while IR24 was susceptible to all eight Xoo strains. The F₁ plants were resistant to all eight Xoo strains, while amongst 56 BQ plants, differential reaction to differential Xoo strain was observed. The resistance of BC₁ plants was segregated. 4. Based on the genotypes of BC₄F₁ population and the investigation of 12 traits of BC₄F₂, quantitative trait loci （QTL） associated with 12 traits were detected using AB-QTL analysis. For 9 yield and its components traits, 28 and 31 QTLs were detected in Wuchang and Hainan, positive alleles from O. minuta （Acc. No. 101133） were 46.4% and 48.4%, respectively. For 3 grain type traits, 12 QTLs were detected in Wuchang, 5 favorable QTL derived from O. minuta （Acc. No. 101133）.5. Using a BC₂F₂ populations and its F₃, F₄ families, we discovered a new bacterial blight resistance gene derived from Oryza minuta （Acc. No. 101133） through genetic analysis and identification of anti-spectrum, and designated as Xa31（t）. Using SSR marker, the Xa31（t） locus was mapped to a region of about 1.76 cM. This locus co-segregated with marker RM144 and was 0.66 cM from marker RM6293 on one side and 1.1 cM from marker RM7654 on the other side, in rice chromosome 11.更多还原