【作者】 白丽；

【导师】 刘伟华；

【作者基本信息】 中国农业科学院 ， 作物种质资源学， 2012， 硕士

【摘要】 向小麦转移野生近缘种的优异基因是小麦育种水平持续提高的重要基础。小麦野生近缘植物含有很多可用于小麦改良的优异基因，包括抗逆、抗病及多花多粒等优良特性基因。建立小麦-野生近缘种的异源二体附加系是有效转移外源优异基因的关键环节。本研究以6个小麦-冰草（Agropyron cristatum,2n=4x=28, PPPP）二体附加系为材料，对其形态学和遗传差异进行了分析，同时利用分子标记对辐照杂交种的渐渗系后代进行了遗传鉴定，研究结果如下：1、利用GISH方法对小麦-冰草6P异源二体附加系进行再鉴定，确认附加了一对冰草染色体。2、形态学分析发现，6个二体附加系表现不同，综合形态学特征与抗白粉病的情况，发现4844-12、5113和5114都具有大穗多粒、旗叶宽而长的特性，并且对白粉病表现中抗，但是4844-12与5113和5114的区别是，后者籽粒干瘪，千粒重较小；5106、II-26与II-29-2i的穗粒数较少，感白粉病，但是II-29-2i具有独特细窄的旗叶，这一点与冰草极为相似，其穗粒数与II-26没有显著性差异，并且显著的高于5106，同时它的千粒重与5114没有显著性差异而高于5113，由此推测在同等水平下，它可能具有高光效特性，但还有待于进一步探讨。附加系材料间农艺性状有不同程度的差异，使用SAS V8.0对其聚类，可将6份材料分为两大类：4844-12、5113、5114与5106、II-26、II-29-2i。3、利用实验室开发的STS分子标记对6份6P二体附加系材料进行分子标记分析，发现6份6P二体附加系材料所附加冰草染色体遗传结构存在差异，对分子标记的结果进行聚类分析，将6份材料归为四类：第一类，4844-12、5113、5114；第二类，5106；第三类，II-26；第四类，II-29-2i。根据不同物种间染色体的共线性进行小麦EST物理图谱基础上的STS分子标记比较分析，做出6P染色体分子标记模式图，进一步确认其为6P附加并验证聚类的分类结果。4、结合上述分子标记分析与农艺性状调查发现，相对于小麦基因组，不同类型的6P染色体发生了明显的结构重排；与传统的期望值不同，外源染色体（6P）的结构重排能够导致附加系数目多于理论数目，也造成了不同附加系在表型上表现不同。5、筛选出实验室开发的312个普通小麦Fukuho及藁城8901背景下的6P染色体STS特异分子标记，对27份GISH检测阴性的辐照M₆代渐渗系进行检测，发现有27对标记能够在材料上出现特异扩增，证明这些渐渗系材料中携带有6P染色质，筛选出的阳性标记可用来快速追踪冰草染色质。本研究中分子标记比较图谱的建立，为6P染色体上特异性状物理图谱定位奠定了重要基础，以此分析染色体结构的重排对于通过远缘杂交向小麦定向转移期望基因及提高育种利用效率具有重要的指导作用。所获得的6P特异标记可用来进一步验证其与多粒性状的相关性，并以此来进行辅助多粒渐渗系的筛选，为异源染色体片段的追踪和辅助育种提供有效手段。更多还原

【Abstract】 Transferring the excellent genes from wild related species to wheat was the important basis forpersistently improving the wheat breeding. The excellent genes from the wild relatives such asdisease-resistence and multi-kernel genes, could be used for wheat improvement. Producing wheat-wildrelated species alien disomic addition lines and analyzing their genetic structure were effective key stepin transferring excellent genes. The study used six wheat-A. cristatum (2n=4x=28, PPPP) disomicaddition lines as materials and analyzed morphology and genetic structure. In addition, molecularmarkers were used to analyze the introgression lines which had been produced by irradiatingF1(4844-12×Gaocheng8901). The results are as following:1. Identifying the wheat-A. cristatum6P disomic addition lines by GISH detection, and choosingthe materials that contained two P chromosomes.2. Differences on agronomic characteristics among the six addition lines were found bymorphology analysis. Combined with the characteristics of morphology and powder mildew-resistance,the results showed that4844-12,5113and5114possessed large kernel number, wide flag leaves andpowder mildew resistance, while5113and5114had smaller-grain weight than4844-12.5106, II-26andII-29-2i had less grain number and were susceptible to powder mildew, but II-29-2i had unique narrowflag leaf which was similar to Agropyron, and its grain number showed no significant difference withII-26but more than5106, meanwhile, the thousand-grain weight was higher than5113and nosignificant difference with5114, so in the same level, II-29-2i may had the characteristic of highphotosynthetic efficiency. The agromomic characteristics were different among the six addition lines,and we clustered and divided them into two types by using SAS V8.0:4844-12,5113,5114and5106,II-26, II-29-2i.3. Using the developed STS molecular markers to analyse the six6P disomic addition lines. Theresults showed that the genetic structure of P chromosomes which added in the six materials weredifferent. Divided the materials into4types by cluster analysis on the molecular markers result:4844-12,5113,5114;5106; II-26; II-29-2i. According to the colinearity between species, STScomparative analysis were based on the physical map of wheat ESTs and the6P mode maps wereconstructed. The maps would contribute to comfirm the6P chromosomes and the types divided bycluster analysis.4. In comprehensiveness, the structure of6P chromosomes occurred genetic rearrangementobviously; Differently from the traditional expectation, genetic rearrangement of alien chromosomescould lead to the number of addition lines more than theory and also produce different phenotypes.5.3126P STS molecular markers were used to analyze27M6introgresion lines which could notbe identified by GISH. There were27markers that could amplify the specific bands and and they couldbe used to trace alien fragments quickly.The comparative map built in the study provided the important basis for specific characteristics’physical mapping on6P chromosomes. To analyse the genetic rearrangement could provide guidance for excellent genes directional transferring and improving the breeding efficiently.6P makers obtainedin the study could be used to do further study on correlation with the characteristic of multi-kernel andassistantly choose introgression lines with multi-kernel, which could provide effective means to tracealien fragments and marker-assisted breeding.更多还原