【作者】 陈德全；

【导师】 李仕贵；

【作者基本信息】 四川农业大学 ， 作物遗传育种， 2004， 博士

【摘要】 本研究利用SSR标记和农艺性状分析对93份我国水稻生产上应用的常规品种、杂交稻亲本和国外优良品种进行了遗传多样性分析；利用四川主要的5个常用不育系和6个恢复系设计不完全双列杂交试验，对不育系、恢复系和组合进行了配合力分析、主成分分析、回归分析和通径分析，并结合1985-2003年四川省审定水稻品种的产量性状改良，对四川水稻育种的效果进行了分析。主要结果如下： 1．SSR标记能将93份材料准确地聚类为籼稻和粳稻两类，并能客观地反映各品种之间的亲缘关系，尽管水稻品种资源的遗传多样性丰富，但聚类分析表明，我国杂交水稻骨干亲本遗传基础狭窄。另一方面，生产上应用的主要恢复系和不育系之间的遗传距离较远，证明了遗传距离的大小和杂种优势存在一定的相关性。与分子标记聚类比较，农艺性状聚类受环境影响较大，较难反映材料的遗传本质。 2．应用Wx基因的微卫星标记484／485和PCR-Acc I分子标记对93份籼、粳水稻品种(系)的Wx基因的多态性进行了研究，并探讨了不同基因型与直链淀粉含量的关系。484／485扩增结果表明，该微卫星标记表现为三种基因型，即Wx~1Wx~1、Wx~2Wx~2和Wx~3Wx~3型，其中籼稻以Wx~1Wx~1和Wx~3rVx~3为主，粳稻以Wx~1Wx~1为主，具有Wx~1Wx~1和rVx~2rVx~2基因型的品种(系)的直链淀粉含量低，具有Wx~3Wx~3的品种(系)的直链淀粉含量高。PCR-Acc I分子标记检测到两种基因型，即GG和TT型，其中GG型的水稻品种直链淀粉含量较高，TT型的水稻品种直链淀粉含量较低。比较分析两种分子标记检测结果，具有Wx~2Wx~2的品种(系)为TT型，Wx~3Wx~3的品种(系)为GG型；Wx~1Wx~1的品种(系)既有TT型又有GG型，但GG型品种的直链淀粉的含量显著高于TT型品种。统计分析表明利用微卫星标记和PCR-Acc I分子标记检测93个水稻品种(系)与直链淀粉含量的相关系数分别为0.867**和0.881**，也即脸基因的遗传变异可解释这些品种(系)直链淀粉含量变异的75%以上。因此，在水稻育种中，可利用上述分子标记辅助选择改良稻米的直链淀粉含量，提高育种效率。3.建立了四川26个主要杂交水稻亲本材料指纹图谱数据库，筛选出了18对多态性位点较多的SSR引物，根据亲缘关系远近，利用l一3对引物就能将任一亲本材料与其他材料区分开来;利用D优527指纹图谱进行品种真伪和纯度鉴定，所构建的指纹图谱库可以为杂交水稻品种保护和快速纯度鉴定提供技术支撑。4.通过不完全双列杂交试验进行配合力、主成分和通径分析结果表明，G46、绵恢725和蜀恢527三个亲本在产量及产量性状一般配合力方面表现优异。G46A/蜀恢527、G46A/绵恢725、D62A/蜀恢527在产量特殊配合力方面表现突出。四川杂交水稻组合在光合作用、叶面积指数(LAI)等“源”性状无显著差异，产量的提高主要来源于“库”的增加，即单穗粒重的提高。5.对24年间四川审定水稻品种的分析表明，四川省水稻品种选育的主攻方向是以杂交稻，尤其是三系中釉中迟熟为主，占整个审定品种总数的60.4%，同时育种水平逐年提高.产量构成因子中着粒数、千粒重、单穗粒重和单穗生产潜力呈增长趋势，产量的提高主要归因于基于着粒数和千粒重的增加而产生的单穗粒重的提高，这一结果与双列杂交分析的结果一致。6.本研究表明，聚合各种优良基因、配合理想的生理、产量及产量构成因子的改良、注重重穗型品种选育是获得水稻高产的重要途径之一，而重穗型三系杂交水稻是目前较为成功的水稻品种选育方法。更多还原

【Abstract】 93 elite rice (Oryza sativa L.), including conventional varieties, hybrid parents, were analyzed with SSR markers. And also the combining ability of 30 hybrid rice and their 5 elite sterile lines and 6 restorer lines were analyzed with Griffing’s diallel cross IV method. 4 newly varieties were added to the former 30 combinations to be used as principal components analysis, correlation analysis, regression analysis and path analysis. The hybrid varieties released in Sichuan from 1985 to 2003 were investigated in yield improvement and genetic analysis. The main results are as follows:l.SSR marker; can accurately distinguish Indica and japonica and have larger molecular polymorphism than that of japonica. SSR polymorphism can reflect the genetic relationship among different varieties. Despite genetically diverse rice resouces, the genetic background of skeleton breeding lines is much limited. The genetic distances between elite sterile lines and restorer lines are much larger than that within each of the two parent groups. Genetic distance has some relationship with heterosis. Compared with clustering analysis with molecular markers, the dendrogram based on agronomic traits is much affected by environment and can hardly reflect the genetic essence of the examined lines.2.The polymorphism of (CT)n of PCR products amplified by microsatellite marker 484/485, and the relationships between Wx genotype and amylose content (AC) were studied. The correlation coefficient of Wx genotype and AC is 0.867** reached very significant level. WxlWxl and Wx2Wx2 genotypes showed significantly lower amylose content and Wx3Wx3 genotype higher amylose content. A PCR-Acc I molecular marker has been developed and used to determine whether the first nucleotide of splice donor site of waxy intron 1 is G or T in 93 rice cultivars lines collected from different areas. Most Wx1 Wx1 and Wx2Wx2 genotypes are TT genotypes and most Wx3Wx3 genotypes are GG genotypes. The correlation of Wx genotype and PCR-Acc I genotype is 0.881** with very significant level.3.We established a fingerprint map database of elite rice breeding lines with three groups of SSR markers. With one 1:0 three SSR markers, we can efficiently distinguish anyone of the 26 elite rice breeding lines from others. This poses a bright usage potential for the detection of variety identity and seed purity. We successful established the fingerprint map of a much spread variety, Diyou 527, and accurately examined the purity of its commercial seed.34.According to the combining ability, principal components and path analysis, G46, Mianhui 725, and Shuhui 527 are the top three lines with their best yield and yield traits performances. Three combinations, including G46/Shuhui527, G46/Mianhui725 and D62/Shuhui527, have significantly the best yield and yield traits performances than other combinations. Source traits, such as photosynthesis efficiency and leaf area index, do not show significant difference. The improvement of rice yield is much attributed to the increase of a sink traits, grain weight per panicle.5.Based on the analysis of hybrid varieties approved within the resent 24 years, we find that the main effort of Sichuan rice breeding is being used to make more late maturing hybrids, and such hybrids accounted for 60.4% of the total approved combinations. The yield level were enhancing yearly with its components traits, such as grain number per panicle, 1000-grain weight, grain weight per panicle and panicle grain yield potential, increasing. The increase of rice yield is mainly attributed to the increase of grain weight per panicle, which is further influenced by grain number per panicle and 1000-grain weight. The result is finely coincide with the former incomplete diallel cross analysis.6.The research indicates that pyramiding excellent genes and regulating yield concerning (or components) traits see two most effective approaches to enhance rice yield. Among yield make-up traits, grain weight is most important. So heavy panicle is the most important characteristic that br更多还原