Dissection of the qTGW1.1 region into two tightly-linked minor QTLs having stable effects for grain weight in rice.
Dissection of the qTGW1.1 region into two tightly-linked minor QTLs having stable effects for grain weight in rice.
复制标题
将 qTGW1.1 区域分解为两个紧密连锁的小 QTL，对水稻粒重具有稳定的影响
DOI：
10.1186/s12863-016-0410-5
复制
发表时间：
2016-06-30
期刊：
影响因子：
2.9
通讯作者：
Zhuang JY
中科院分区：
文献类型：
--
作者：
Zhang HW;Fan YY;Zhu YJ;Chen JY;Yu SB;Zhuang JY
作物的大多数农艺性状是受多基因控制和环境因素影响的复杂性状。尽管人们在精细定位和克隆水稻产量相关性状的主效数量性状基因座（QTL）方面做了大量工作，但对次效QTL的研究才刚刚开始。继先前解剖的QTL的粒重和粒大小在12 Mb的长臂上的1号染色体在水稻，本研究针对一个假定的QTL区域进行更精确的定位和分析的基因型由环境的相互作用的次要QTLs.Results4个BC 2F 10植株的籼稻杂交稻97/97/97/MY 46。它们携带重叠的杂合片段，共同覆盖了先前检测到的qTGW1.1的整个推定区域。从四个植株的自交后代中培育出四套近等基因系。每个近等基因组包括32个MY 97纯合株系和32个MY 46纯合株系，这些纯合株系在相应的杂合区域中存在差异。它们生长在具有不同生态条件的两个地点，并测量了千粒重、粒长和粒宽。两个QTL在835.2-kb的区间内分离，两侧是DNA标记Wn 28447和RM 11569。它们在两种环境中都表现出一致的效果。位于120.4 kb区间Wn 28447-RM 11543内的qTGW1.1a对所有三个性状都有显著影响，其中来自于Wn 97的增强等位基因对粒重的影响比对粒长和粒宽的影响更大。位于521.8 kb区间RM 11554-RM 11569的qTGW1.1b对粒重和粒长有显著影响，来自MY 46的增强等位基因对粒长的影响比对粒重的影响更大。利用qTGW 1. 1a和qTGW 1. 1b分离的5个NIL-F2群体进行验证试验，结果表明这2个QTL的表现一致。结论在不存在主效QTL分离的情况下，可以分离出效应较小的紧密连锁QTL。复杂性状的微效QTL在不同环境中的作用一致，为利用分子标记辅助选择技术筛选多个微效QTL的有益等位基因提供了可能。
BackgroundMost agronomical traits of crop species are complex traits controlled by multiple genes and affected by environmental factors. While considerable efforts have been made to fine-map and clone major quantitative trait loci (QTLs) for yield-related traits in rice, it is not until recently that the attention has been paid to minor QTLs. Following previous dissection of QTLs for grain weight and grain size in a 12-Mb interval on the long arm of chromosome 1 in rice, this study targeted at one putative QTL region for a more precise mapping and for analyzing the genotype-by-environment interaction of minor QTLs.ResultsFour BC2F10 plants of the indica rice cross ZS97///ZS97//ZS97/MY46 were selected. They carried overlapped heterozygous segments that jointly covered the entire putative region for qTGW1.1 detected previously. Four sets of near isogenic lines (NILs) were developed from selfing progenies of the four plants. Each NIL set consisted of 32 ZS97 homozygous lines and 32 MY46 homozygous lines that differed in the corresponding heterozygous region. They were grown in two locations having distinct ecological conditions and measured for 1000-grain weight, grain length and grain width. Two QTLs were separated in an 835.2-kb interval flanked by DNA markers Wn28447 and RM11569. They both showed consistent effects across the two environments. The qTGW1.1a located within the 120.4-kb interval Wn28447 − RM11543 significantly affect all the three traits with the enhancing allele derived from ZS97, showing a stronger influence on grain weight than on grain length and width. The qTGW1.1b located in the 521.8-kb interval RM11554 − RM11569 significantly affect grain weight and length with the enhancing allele derived from MY46, having a stronger influence on grain length than on grain weight. Consistent performance of the two QTLs was confirmed in a validation experiment using five NIL-F2 populations segregated for either qTGW1.1a or qTGW1.1b.ConclusionSeparation of closely-linked QTLs having small effects is achievable in the absence of major-QTL segregation. Minor QTLs for complex traits could act consistently in diverse environments, offering the potential of pyramiding beneficial alleles of multiple minor QTLs through marker-assisted selection.