利用东乡野生稻进行超级稻低温萌发力改良及QTL定位

发布时间：2018-07-11 10:57

  本文选题：水稻 + 农艺性状　； 参考：《沈阳农业大学》2017年硕士论文

【摘要】：水稻直播不需要育秧与移栽直接将种子播种于田里,因此是一种轻型、高效且节水的栽培方式,对实现水稻生产的规模化、机械化具有重要意义。种子成苗的好坏是直播栽培应用于推广的先决条件,低温萌发力是限制直播稻种子成苗的主要因素之一。培育新的或改良现有水稻品种的耐低温萌发特性,是直播稻发展亟待解决的问题。在普通野生稻里,位于全球最北端的东乡野生稻蕴藏着耐旱、耐寒、耐瘠、抗病虫、高产等有利基因,素有植物中的"大熊猫"之美誉,目前通过东乡野生稻培育的稻种已有57种之多。本研究将利用东乡野生稻和超级稻沈农265构建的140份回交重组自交系,对超级稻沈农265的低温萌发力进行改良,利用SSR分子标记技术,结合混合分组分离方法(BSA)筛选耐冷连锁标记并进行QTL初步定位。主要内容和结果如下:1.140份回交重组自交系群体在株高,穗长,结实率,千粒重方面呈明显的正太分布。其中整体株高平均值为95.31cm,标准偏差为8.72。穗长平均值为17.03cm,标准偏差为1.31,大部分自交系穗长在15cm-18cm范围内,个别自交系穗长达到25cm左右。结实率平均值为0.92,标准偏差为0.03,极少数自交系结实率较低,为75%左右。千粒重平均值为25.75g,标准偏差为3.58,多数自交系千粒重在25g左右,少数能达到38g左右。以上结果表明群体的各农艺性状呈现连续分布趋势,为明显的多基因控制的数量性状,且群体内变异丰富。株高与结实率之间呈显著的负相关性,结实率与千粒重呈极显著正相关,与前人研究结果一致。2.进行低温发芽力的鉴定结果表明回交重组自交系群体的低温萌发力呈现明显的连续分布趋势,且呈正态分布。表明群体中存在不同等级的耐冷性材料,以群体低温发芽力耐冷等级进行划分,群体耐冷性都划分为3个等级,其中发芽率极强的占了 5%,耐冷性极弱的占了 7.9%。且通过相关性分析,低温发芽力与各产量构成因素间均无相关性,对群体的产量指标和低温发芽力做性状间的相关分析,低温发芽力与产量各指标之间均无明显相关性,说明低温条件下水稻发芽不受株高、穗长、结实率与千粒重的影响,低温发芽力独立于产量性状遗传,为超级稻低温发芽力的改良奠定了理论基础。3.通过农艺性状和低温发芽力的综合表现,筛选了 7份农艺性状表现良好(类似沈农265),低温发芽力较强的材料,这7份材料株高平均为96.8cm,穗长平均为17.4cm,穗数平均为14,穗粒数平均值为144,结实率平均为92.29%,千粒重平均为25.42g,低温发芽率平均为93%,这些材料在产量性状上与超级稻沈农265类似,但低温发芽力却得到显著提升,为超级稻沈农265低温发芽力改良提供了很好的基础材料。4.从水稻基因组上挑选158对均匀分布在12条染色体上的SSR引物,经筛选,在亲本中表现出明显多态性的有46对,多态率为33.33%。利用这46对SSR引物对140个株系的标记带型进行检测,利用IciMapping4.1作图软件定位出19个有关低温发芽力QTL,分别位于第1、2、4、5、6、7、11号染色体。其中第1染色体有3个,第2染色体定位到7个,且这些QTL在第2条染色体上密集分布。第4和第6染色体分别1个,第5染色体和第11染色体分别有2个。这些QTL的LOD值介于2.57-5.00之间,加性效应值在-15.30—14.43之间,单个QTL贡献率介于11.48%-17.72%之间。其中贡献率最大的两个QTL分别位于第1染色体上的标记RM562-RM8129和RM8219-RM3825之间,贡献率分别为17.71%和17.72%。5.在回交重组自交系群体中选择耐冷性极强和耐冷性极弱的材料各10个,构建耐冷和不耐冷2个极端混池,进一步采用BSA法,利用在亲本中有多态性的46对引物在两个混池中进行多态性检测,在第2染色体上检测到两对在混池中具有多态性的引物RM324、RM166,在第5和第9染色体上的各检测到一对在混池中具有多态性的引物RM534 和 RM257。
[Abstract]:The direct seeding of rice does not need seedling and transplant to seed the seed directly in the field. Therefore, it is a light, efficient and water-saving cultivation method. It is of great significance to realize the scale and mechanization of rice production. The seed seedling is the first piece of the direct seeding cultivation, and the low temperature germination force is the restriction of the seeding of direct seeding rice. One of the main factors is to cultivate new or improved low temperature germination characteristics of existing rice varieties, which is an urgent problem to be solved for the development of direct seeding rice. In the common wild rice, the Dongxiang wild rice located at the north end of the world contains drought tolerance, cold tolerance, barren resistance, disease resistance and high yield, and is known as the "giant panda" in plants. There are 57 species of rice cultivated in Dongxiang wild rice. In this study, 140 backcross recombined inbred lines of Dongxiang wild rice and super rice Shen Nong 265 were used to improve the low temperature germination power of super rice Shen Nong 265. Using SSR molecular marker technique, combined with mixed grouping separation method (BSA), the cold resistant linkage markers were screened and QTL preliminary determination was carried out. The main contents and results are as follows: 1.140 recombined recombined inbred lines have obvious positive and positive distribution in plant height, ear length, seed setting rate and 1000 grain weight, of which the average height of the whole plant is 95.31cm, the standard deviation is 8.72. ear length 17.03cm, the standard deviation is 1.31, the ear length of the large part of the inbred line is within the range of 15cm-18cm, and individual inbred lines are in the range of the large part of the inbred line. The ear length reached about 25cm, the average value of seed setting rate was 0.92, the standard deviation was 0.03, the seed setting rate of the very few inbred lines was about 75%. The average value of 1000 grain weight was 25.75g, the standard deviation was 3.58, the 1000 grain weight of most inbred lines was about 25g, and the few could reach about 38g. There was a significant negative correlation between the plant height and the seed setting rate, and the seed setting rate was significantly positively correlated with the 1000 grain weight. The identification results of.2. at low temperature showed that the low temperature germination of the reformed inbred lines showed a significant continuous distribution. It shows that there are different grades of cold resistant materials in the population, and the cold tolerance of population is divided into 3 grades, with 3 grades of cold tolerance, 5% of them with strong germination rate, and the very weak cold tolerance is accounted for by the correlation analysis. There was no correlation between the correlation analysis between the yield indexes of the population and the characters of the low temperature germination power, and there was no significant correlation between the low temperature germination power and the yield indexes. It indicated that the germination of rice under low temperature was not affected by plant height, ear length, seed setting rate and 1000 grain weight, and the low temperature germination power was independent of yield traits, and it was the low temperature germination power of super rice. The improvement laid the theoretical basis for.3. through the comprehensive performance of agronomic traits and low temperature germination power, and screened 7 varieties of good agronomic traits (similar to Shen Nong 265), with strong germination capacity at low temperature. The average height of the 7 material plants was 96.8cm, the average ear length was 17.4cm, the average ear number was 14, the grain number per ear was 144, and the seed setting rate averaged 92.29%. The average 1000 grain weight is 25.42g and the low temperature germination rate is 93%. These materials are similar to the super rice Shen Nong 265 in the yield traits, but the germination ability of the low temperature is significantly improved, which provides a good foundation material for the improvement of the low temperature germination power of the super rice Shen Nong 265, and the selection of 158 pairs of SSR on the 12 chromosomes from the rice genome. Primers, after screening, showed 46 pairs of obvious polymorphisms in the parents, and the polymorphism rate was 33.33%. using the 46 pairs of SSR primers to detect the tagged bands of 140 strains, and using IciMapping4.1 mapping software to locate 19 low temperature germinating forces QTL, respectively, on chromosome 1,2,4,5,6,7,11. First of the first chromosomes were stained with second chromosomes. The body is located to 7, and these QTL are densely distributed on second chromosomes. Fourth and sixth chromosomes are 1, fifth and eleventh chromosomes have 2 respectively. The LOD value of these QTL is between 2.57-5.00, the additive effect value is between -15.30 and 14.43, and the contribution rate of individual QTL is between 11.48%-17.72%. Among which the largest contribution rate is two QTL points. It is not located between the first chromosome markers RM562-RM8129 and RM8219-RM3825, the contribution rate is 17.71% and 17.72%.5. in the backcross recombined inbred lines to select 10 materials with very strong cold resistance and very cold tolerance. 2 Extreme mixed pools with cold and cold tolerance are constructed, and the BSA method is used for further exploitation, and 46 pairs of polymorphic pairs in the parents are used. Polymorphisms were detected in two mixed pools, and two pairs of polymorphic primers RM324, RM166, and polymorphic primers on the fifth and ninth chromosomes were detected on the second chromosome, and a pair of polymorphic primers RM534 and RM257. were detected on the fifth and ninth chromosomes.
【学位授予单位】：沈阳农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S511.9
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本文编号：2114930