基于SNP芯片技术的小麦抗白粉病基因定位

发布时间：2018-04-19 07:19

本文选题：小麦 + 白粉病　；参考：《山西大学》2016年硕士论文

【摘要】：小麦白粉病,由病原菌Blumeria graminis f.sp.tritici侵染造成,成为小麦增加产量、提高品质必须面临的严峻疾病挑战。在中国,定位抗白粉病新基因,发掘抗白粉病材料,进一步推进小麦抗病分子育种工作,是小麦作物研究中非常重要的内容。中间偃麦草(Thinopyrum intermedium,= 42,JJJsJsStSt)是小麦遗传改良的优异基因库,利用桥梁亲本小麦-偃麦草部分双二倍体即八倍体小偃麦(TAI7044、TAI7045、TAI7047等),可以克服普通小麦和中间偃麦草直接进行远缘杂交所面临的杂种不育、后代疯狂分离、育种周期长、有益基因转移困难等技术性难题。CH09W80是课题组选育的一个高抗小麦白粉病品系。本实验以CH09W80和绵阳11为亲本,构建F,群体、F2群体、BC1群体以及F2:3家系,使用密度为iSelect 90K的小麦基因组SNP芯片扫描,并结合SSR标记对CH09W80的抗白粉病基因进行了初步定位。本试验主要结果如下:(1)利用白粉菌对中间偃麦草、TAI7047、CH09W80及其小麦亲本(TY768、JC5号、JT170)进行苗期抗性鉴定,结果表明新种质CH09W80与其野生亲本中间偃麦草和八倍体小偃麦TAI7047对所选的白粉菌菌株抗性表现相近,而小麦亲本TY768、JT170、JC5号均表现为感病。(2)利用白粉菌株E09对CH09W80/绵阳11的F1、F2、BC1群体及其F2:3家系进行成株期抗性鉴定,其F,群体不发生性状分离且均抗白粉病,F2群体、BC1群体、F2:3家系均发生性状分离,符合3R:1S,1R:1S,1R:2H:1S的分离比。推测新种质CH09W80中抗白粉病基因是显性核基因,并暂时命名为PmCH09W80。(3)利用基因组原位杂交(GISH)技术对新种质CH09W80中渗入的染色体片段进行检测,在CH09W80中并未检测到明显的中间偃麦草外源染色体片段,其原因可能是CH09W80中含有的外源染色体片段太小,导致目前的GISH技术无法检测到。(4)利用BSA法进行SSR标记初步筛选以及iSelect 90K SNP芯片扫描。用SSR标记在抗、感亲和抗、感池间初步筛选,发现染色体2A上Xwmc522具有显著多态性;用90K SNP芯片检测到3198个多态性SNP位点,多态性比率为3.92%。其中,2A染色体上所含的差异标记最多,达384个。通过进一步分析发现,其中313个标记位于2AL上,47个标记位于2AS上。并且,对差异SNP标记的染色体位置的分析显示,在100-105cM和150-155cM两个区域附近分布的差异SNP位点最多。因此,把对CH09W80中的白粉病抗性基因的研究工作集中在小麦2A染色体的100-105cM和150-155cM两个区域附近。(5)标记连锁分析发现,筛选到的SSR标记与PmCH09W80紧密连锁,连锁关系是:Xwmc522-Xgwm356-PmCH09W80-Xgwm526,两侧标记Xgwm56、Xgwm526与PmCH09W80连锁距离分别为3.5cM、7.8cM。利用小麦SSR遗传图谱以及中国春缺体、端体体系将PmCH09W80定位于小麦2AL染色体上。进一步与位于2AL上的Pm4、Pm50比较发现,PmCH09W80可能是2AL上的一个新基因。
[Abstract]:Wheat powdery mildew, caused by pathogen Blumeria graminis f.sp.tritici, is a severe disease challenge to increase wheat yield and improve quality.In China, locating new genes for powdery mildew resistance, exploring powdery mildew resistant materials and further promoting molecular breeding of wheat resistance are very important contents in wheat crop research.Thinopyrum intermedium = 42 JJs JsStSt. is an excellent gene bank for genetic improvement of wheat.The hybrid sterility faced by wheat and Thinopyrum intermedium can be overcome by using the bridge parent wheat-Thinopyrum triticum partial diploid, that is, the octoploid triticlopyrum triticum, TAI7044 and TAI7045 and TAI7047, which can overcome the hybrid sterility faced by direct distant hybridization between common wheat and Thinopyrum intermedium, and the progenies are madly separated and breeding cycle is long.CH09W80 is a high resistant wheat powdery mildew strain selected by our team.In this experiment, CH09W80 and Mianyang 11 were used as parents to construct F, F _ 2 population BC1 and F _ 2: 3 families. Wheat genome SNP microarray with density of iSelect 90K was used to scan the wheat genome, and the wheat powdery mildew resistance gene of CH09W80 was preliminarily mapped with SSR markers.The main results of this experiment were as follows: (1) using powdery mildew to identify the seedling resistance of TY768 (JC5) and its parent, TY768 (JC5), the resistance of Thinopyrum intermedium to TAI7047 (CH09W80) and its parent, TY768 (JC5).The results showed that the resistance of the new germplasm CH09W80 to the selected powdery mildew strain was similar to that of its wild parents, Thinopyrum intermedium and TAI7047.The wheat parent TY768, JT170, JC5, was susceptible to disease. The white powder strain E09 was used to identify the plant resistance of CH09W80/ Mianyang 11 F1F2BC1 population and F2: 3 families at the adult stage, and the wheat parent TY768, JT170, JC5, was used to identify the resistance of the white powder strain E09 to the F1F2BC1 population of CH09W80/ Mianyang 11.There was no trait segregation in F, F 2 population and resistance to powdery mildew in F 1 F 1 population F 2: 3 families, which was consistent with the segregation ratio of 3R: 1R: 1R: 1R: 2H: 1s.It was inferred that the powdery mildew resistance gene in the new germplasm CH09W80 was a dominant nuclear gene, and was tentatively named PmCH09W80.63) the chromosome fragments infiltrated in the new germplasm CH09W80 were detected by in situ hybridization (Gish) technique.No obvious exogenous chromosome fragments were detected in CH09W80, which may be due to the fact that the exogenous chromosomes contained in CH09W80 are too small.As a result, the current GISH technology can not detect. 4) using BSA method to screen SSR markers and scan iSelect 90K SNP chip.SSR markers were used to detect the polymorphism of Xwmc522 on chromosome 2A and 3 198 polymorphic SNP loci were detected by using 90K SNP microarray, the ratio of polymorphism was 3.92%.The number of differential markers on chromosome 2 A was 384.Through further analysis, it was found that 313 of the markers were located on 2AL and 47 on 2AS.Moreover, the analysis of the chromosomal location of differential SNP markers showed that there were the most different SNP loci in the vicinity of 100-105cM and 150-155cM.Therefore, the study of powdery mildew resistance genes in CH09W80 was focused on the linkage analysis of 100-105cM and 150-155cM in wheat chromosome 2A. The results showed that the screened SSR markers were closely linked to PmCH09W80.The linkage relationship is: Xwmc522-Xgwm356-PmCH09W80-Xgwm526, the linkage distance between Xgwm526 and PmCH09W80 is 3.5cmm356-PmCH09W80-Xgwm526, and the linkage distance between Xgwm356-PmCH09W80-Xgwm526 and PmCH09W80 is 7.8 cm.The PmCH09W80 was mapped to the 2AL chromosome of wheat using SSR genetic map and Chinese spring deficient body and terminal system.Compared with Pm4Pm50 on 2AL, it was found that PmCH09W80 might be a new gene in 2AL.
【学位授予单位】：山西大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S435.121.46

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