【作者】 杨旭东；

【导师】 查仁明；

【作者基本信息】 贵州大学 ， 作物， 2019， 硕士

【摘要】 水稻是全球范围内最重要的粮食作物之一,世界上至少有一半人口以稻米为食。水稻大多数农艺性状是受多基因控制的数量性状,水稻分子设计育种的前提和基础是相关基因的鉴定和分离。每个染色体片段代换系只含有一个或少数几个来自供体亲本的片段,能够消除背景干扰,因此被认为是进行QTL（Quantitative Trait Locus）分析的理想材料。长粒染色体片段代换系Z1347是以粳稻日本晴为受体、西南大学水稻研究所自主选育的恢复系西恢18号为供体,通过高代回交和分子标记辅助选择培育而来的。本论文对Z1347进行分子鉴定、形态分析和重要农艺性状评价,并用受体日本晴为母本与长粒染色体片段代换系Z1347为父本构建的F₂分离群体,进行了粒长等重要农艺性状QTL定位。主要研究结果如下:1、Z1347代换片段的鉴定在前期研究的基础上,用Z1347代换片段上的90个SSR标记及代换片段外的42个SSR标记对10株Z1347进行进一步代换片段鉴定和遗传背景检测,发现10个单株的代换片段一致,其没有检测出背景片段,说明Z1347已纯合。Z1347共含有来自西恢18号的16个代换片段,位于水稻12条染色体。其中最短代换长度为0.95Mb,最长代换长度为9.1Mb。代换总长度合计52.3Mb,平均代换长度为4.36Mb。2、Z1347的农艺性状分析与受体日本晴相比,Z1347的粒长、长宽比、二次枝梗数、总粒数和千粒重显著增加;Z1347的株高、有效穗数、粒宽和结实率显著减少;Z1347的穗长、一次枝梗数、每穗实粒数和单株产量与日本晴相比无显著差异。暗示了Z1347中携带了来自西恢18号的多个差异性状的QTL。3、粒长及其它农艺性状在次级F₂群体的分布和遗传分析以受体日本晴为母本与长粒染色体片段代换系Z1347为父本杂交F₁籽粒呈长粒型,说明Z1347的长粒可能为显性遗传。但经渐近显著性（双侧）测验,这些性状均呈连续分布,粒长性状的近似P值为0.340、粒宽性状的近似P值为0.291、株高性状的渐近显著性（双侧）近似P值为0.696、穗长P值为0.068、一次枝梗数P值为0.153、每穗实粒数P值为0.445、千粒重P值为0.505均大于0.05,符合正态分布。有效穗数、二次枝梗数、长宽比、总粒数、单株产量的P值均小于0.05,不符合正态分布,表明这些性状仍受多基因控制,需要进一步分解。4、次级F₂群体性状的相关性分析大多数性状之间呈显著正相关性或负相关性,粒长与株高、穗长、一次枝梗数、二次枝梗数、长宽比、每穗实粒数、总粒数、千粒重和单株产量呈显著正相关性,与有效穗数、粒宽和结实率呈正相关性;粒宽与千粒重呈显著正相关性,与穗长、一次枝梗数、二次枝梗数、长宽比和总粒数呈显著负相关性,与粒长和结实率呈正相关性,与有效穗数、株高、每穗实粒数和单株产量呈负相关性;长宽比与有效穗数、株高、穗长、一次枝梗数、二次枝梗数、粒长、每穗实粒数、总粒数、千粒重和单株产量呈显著正相关性,与粒宽呈显著负相关性,与结实率呈负相关性。其中相关系数最大是总粒数与二次枝梗数,相关系数为0.845,说明总粒数的多少取决于二次枝梗数的多少。5、Z1347粒长及其它农艺性状QTL定位选用代换片段中效果较好的SSR（Simple Sequence Repeats）标记对以受体日本晴为母本和长粒染色体片段代换系Z1347为父本杂交产生的次级F₂群体中的8个重要农艺性状进行QTL定位,共鉴定出17个QTL,分布在除第4、5、8、10、12外的其它染色体上。粒长QTL有2个,qGL3与第3染色体上的RM5626连锁,qGL7与第7染色体上的RM6063连锁;长宽比QTL有3个qRLW3与第3染色体上的RM5626连锁、qRLW7与第7染色体上的RM6063连锁,qRLW9与第9染色体上的RM5389连锁;株高QTL（qPH1和qPH3）、有效穗数QTL（qPN3）、二次枝梗数QTL（qNSB7）、穗长QTL（qPL1、qPL6、qPL7和qPL11）、总粒数QTL（qSPP1、qSPP2和qSPP7）、千粒重QTL（qGWT3）。更多还原

【Abstract】 Rice is one of the most important food crops in the world,and at least half of the world’s population feeds on rice.Most agronomic traits of rice are quantitative traits controlled by multiple genes.The identification and isolation of related genes are the premise and fo foundation rice molecular design breeding.Each chromosome fragment substitution line contains only one or a few fragments from the donor parent,which can eliminate background interference,so it is considered as an ideal material for QTL(Quantitative Trait Locus)analysis.The long-grain chromosome fragment substitution line Z1347 is a restorer of Xihui 18,which is a self-selected breeding line of indica rice,and is independently selected by the Rice Research Institute of Southwest University.It is cultivated through high-generation backcrossing and molecular marker-assisted selection.In this paper,the molecular identification,morphological analysis and evaluation of important agronomic traits of Z1347 were carried out,and the F2 segregating population constructed by the receptor Nipponbare as the female parent and the long-length chromosome fragment substitution line Z1347 as the male parent was used to locate QTL for important agronomic traits such as grain length.The main research results are as follows:1.Identification of Z1347 substitution segmentsOn the basis of previous studies,the 90 SSR markers on the Z1347 substitution fragment and 42 SSR markers outside the substitution fragment were used to further identify the substitution fragment and detect the genetic background of 10 strains of Z1347.It was found that the substitution fragments of 10 individual strains were consistent,and no background fragments were detected,indicating that Z1347 was homozygous.Z1347 contains 16 substitution fragments from Xihui 18,located on 12 chromosomes of rice.The shortest substitution length was 0.95 Mb,and the longest substitution length was 9.1Mb.The total substitution length was 52.3Mb,and the average substitution length was 4.36 Mb.2.Analysis of agronomic traits of Z1347Compared with the receptor Nipponbare,the grain length,aspect ratio,secondary branch number,total grain number and 1000-grain weight of Z1347 increased significantly;the plant height,effective panicle number,grain width and seed setting rate of Z1347 decreased significantly;There were no significant differences in ear length,primary branch number,grain number per ear and yield per plant between Z1347 and Nipponbare.It was suggested that Z1347 carried QTL of several different characters from xihui 183.Distribution and genetic analysis of grain length and other agronomic traits in secondary F2 populationThe F1 grain with the recipient Nipponbare as the female parent and the long-length chromosome fragment substitution line Z1347 was a long-grain type,indicating that the long grain of Z1347 may be dominantly inherited.However,the asymptotically significant(bilateral)test showed continuous distribution of these traits.The approximate P value of the grain length trait was 0.340,the approximate P value of the grain width trait was 0.291,and the approximate P value of the plant height traits(bilateral)was 0.696,the ear length P value was 0.068,the primary branch number P value was 0.153,the P value of the actual grain number per spike was 0.445,and the P value of 1000 grain weight was 0.505,which were greater than 0.05,which were consistent with the normal distribution.The P values of effective panicle number,secondary branch number,length-width ratio,total grain number and yield per plant were all less than 0.05,which did not conform to the normal distribution,indicating that these traits are still controlled by multiple genes and need further decomposition.4.Correlation analysis of secondary F2 population traitsGrain length was positively correlated with plant height,panicle length,primary branch number,secondary branch number,length-width ratio,grain number per panicle,total grain number,1000-grain weight and yield per plant,and positively correlated with effective panicle number,grain width and seed setting rate;Grain width was positively correlated with 1000-grain weight,and was negatively correlated with panicle length,primary branch number,secondary branch number,length-width ratio and total grain number,positively correlated with grain length and seed setting rate,and negatively correlated with effective panicle number,plant height,grain number per panicle and yield per plant.The length-width ratio was positively correlated with effective panicle number,plant height,panicle length,primary branch number,secondary branch number,grain length,grain number per panicle,total grain number,1000-grain weight and yield per plant,significantly negatively correlated with grain width,and negatively correlated with seed setting rate.The correlation coefficient was the total number of total grains and the number of secondary branches,and the correlation coefficient was 0.845,indicating that the total number of grains depends on the number of secondary branches.5.QTL mapping of Z1347 grain length and other agronomic traitsQTL mapping of 8 important agronomic traits in the secondary F2 population produced by the crossover of the Japanese Nipponbare and the long-length chromosome fragment substitution line Z1347 was carried out by using the SSR(Simple Sequence Repeats)markers with good effect in the substitution fragment.a total of 17 QTLs were identified and distributed on chromosomes other than 4th,5th,8th,10 th and 12 th.There were two QTLs with grain length,q GL3 was linked to RM5626 on chromosome 3,q GL7 was linked to RM6063 on chromosome 7;Length-width ratio has three QTLs,q RLW3 linked to RM5626 on chromosome 3,q RLW7 is linked to RM6063 on chromosome 7,and q RLW9 is linked to RM5389 on chromosome 9;plant height QTL(q PH1 and q PH3),effective panicle number QTL(q PN3),secondary branch number QTL(q NSB7),spike length QTL(q PL1,q PL6,q PL7 and q PL11),total particle number QTL(q SPP1,q SPP2 and q SPP7),1000-grain weight QTL(qGWT3).更多还原