分子标记辅助选择Pi9基因培育抗稻瘟病籼稻新品系

发布时间：2018-02-07 16:13

本文关键词： 水稻稻瘟病抗性 Pi9基因分子标记辅助选择育种抗病纯系　出处：《湖南农业大学》2015年硕士论文　论文类型：学位论文

【摘要】：水稻是世界上重要的粮食作物,稻瘟病是水稻最主要的真菌性病害之一,流行年份可使水稻减产10%～30%,是水稻高产稳产的主要限制因素。实践证明,培育和合理利用抗病品种是控制此病害最经济有效和对环境安全的手段,因此需要培育抗谱广、抗性稳定并且持久的抗稻瘟病水稻品种。本研究根据广谱持久抗瘟基因Pi9的内含子序列设计特异功能标记Ins2-1,通过分子标记辅助选择和连续回交育种,定向改良21份水稻受体亲本的稻瘟病抗性。主要研究结果如下：1.通过对对实验室保存的10个稻瘟菌菌株进行培养、继代及纯化过程了解了在番茄-燕麦培养机上稻瘟菌菌株的大致生长周期与产孢情况。其中：有3个小种保存完好,7个小种已经被污染；纯化后获得了对应的7个无污染的小种；对这10个小种进行诱导产孢,观察产孢情况发现,两个小种产孢能力较强,5个小种的产孢能力一般,3个小种不产孢；观察各小种菌丝颜色发现,KOH的菌丝为黑色,195-2-2、X2007A-7菌丝为白色,其余7个菌株菌丝均为深灰黑色；通过对这10个稻瘟菌菌株的培养,可以得知各稻瘟菌菌株在番茄-燕麦培养基上的生长周期约为20 d。2.利用25份稻瘟菌菌株对感病对照材料C039、21份水稻受体材料及抗稻瘟病基因Pi9供体75-1-127进行室内接种表型鉴定,利用田间病圃发病检验所有供试水稻材料的稻瘟病抗性,结果表明供试受体材料抗谱不广,抗性不强,需要进行抗性改良；另外,抗谱表明这些亲本中可能含有抗菌谱与Pi9互补的新稻瘟病抗性基因,通过回交改良这些受体亲本的稻瘟病抗性,或许可以得到抗谱比Pi9供体亲本75-1-127更广,同时抗性也更强的新品种。3.分子标记Ins2-1在Pi9基因供体亲本75-1-127及21份受体亲本材料之间存在稳定且明显的多态性,多态率为100%。在大围山天然病圃对所有供试材料进行诱导发病后,利用分子标记Ins2-1对丰源B×75-1-127与E32×75-1-127 BC6F1群体中的随机取样单株进行基因型鉴定,以检测分子标记的辅助选择效率,结果表明Ins2-1标记基因型的稻瘟病抗性表型选择效率为100%,证明此标记能够用于MAS育种实践中作为选择的依据。4.连续数年利用分子标记Ins2-1进行MAS育种,综合田间农艺性状考察,目前已经获得5个组合的数个BC6F3株系,5个组合的BC6F2群体,3个组合的BC6F1群体,另外还有7个回交代数较低的组合,为进一步定向改良这20份受体亲本的稻瘟病抗性、培育抗病纯系打下了良好基础。5.利用特异显性分子标记Ins2-1辅助选择将Pi9基因转育到受体亲本1701中,并通过连续回交和自交,获得了含Pi9基因且遗传背景接近受体亲本的BC6F2群体；通过对BC6F3株系标记基因型和室内接种表型鉴定,筛选出一个抗病纯系“抗瘟1701”,为培育抗稻瘟病水稻新品种(组合)奠定了基础。
[Abstract]:Rice is one of the most important food crops in the world. Rice blast is one of the most important fungal diseases in rice. Breeding and rational use of disease-resistant varieties are the most economical, effective and environmentally safe means to control the disease, so it is necessary to develop a broad spectrum of resistance. In this study, we designed a special marker Ins2-1 based on the intron sequence of the broad-spectrum persistent blast resistance gene Pi9, and used molecular marker assisted selection and continuous backcross breeding. The rice blast resistance of 21 rice receptor parents was improved. The main results were as follows: 1. 10 strains of rice blast were cultured in the laboratory. In the course of subculture and purification, the growth cycle and sporulation of rice blast strain on Tomato oat culture machine were studied. Among them, 3 species were well preserved and 7 species had been contaminated. After purification, 7 species without pollution were obtained, and the spore production of the 10 species was induced. The results showed that the sporulation ability of two species was strong, the sporulation ability of 5 species was general, and 3 species were not. The mycelium of Koh was black 195-2-2X 2007A-7, the other 7 strains were dark gray black, and the 10 strains of rice blast were cultured, the results showed that the hypha of Koh was black and the other 7 strains were dark gray black, and the results showed that the mycelium of Koh was white and the other 7 strains were dark gray black. It can be known that the growth cycle of each rice blast strain on Tomato oat medium is about 20 d.2.21 rice receptor materials and Pi9 donor of blast resistance gene 75-1-127 were identified by 25 strains of rice blast strain. The resistance to blast of all rice tested in the field disease nursery was tested. The results showed that the resistance spectrum was not wide and the resistance was not strong, so resistance improvement was needed. The resistance spectrum indicated that these parents may contain new blast resistance genes that complement Pi9 with antibacterial spectrum. By backcrossing, the resistance to blast of these recipient parents may be wider than that of Pi9 donor parent 75-1-127, and the resistance spectrum of these parents may be wider than that of Pi9 donor parent 75-1-127, and the resistance spectrum of these parents may be wider than that of Pi9 donor parent 75-1-127. At the same time, there was a stable and obvious polymorphism of molecular marker Ins2-1 between 75-1-127 and 21 recipient parents of Pi9 gene donor parents, and the polymorphic rate was 1000.After Daweshan natural disease nursery, all the tested materials were induced to develop disease. Genotypes of randomly sampled individual plants in Fengyuan B 脳 75-1-127 and E32 脳 75-1-127 BC6F1 populations were identified by molecular marker Ins2-1. The results showed that the efficiency of phenotypic selection of rice blast resistance with Ins2-1 marker genotype was 100, which proved that the marker could be used as the basis for selection in MAS breeding practice. The molecular marker Ins2-1 was used for MAS breeding for several years, and the field agronomic characters were investigated. At present, five combinations of several BC6F3 strains, five combinations of BC6F2 populations, three combinations of BC6F1 populations, and seven combinations with lower back metasomatism have been obtained to further improve the blast resistance of the 20 recipient parents. The breeding of disease-resistant pure lines laid a good foundation .5.Using specific dominant molecular marker Ins2-1 assisted selection to transfer Pi9 gene into recipient parent 1701, and through continuous backcrossing and self-crossing, the BC6F2 population containing Pi9 gene and genetic background close to receptor parent was obtained. Based on the identification of marker genotypes and indoor inoculation phenotypes of BC6F3 strains, a resistant pure line "resistance to blast 1701" was selected, which laid a foundation for the breeding of new rice varieties (combinations) resistant to rice blast.
【学位授予单位】：湖南农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S435.111.41

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