Fine linkage mapping enables dissection of closely linked quantitative trait loci for seed dormancy and heading in rice
Fine linkage mapping enables dissection of closely linked quantitative trait loci for seed dormancy and heading in rice
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DOI：
10.1007/s00122-003-1364-3
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发表时间：
2003-07
影响因子：
5.4
通讯作者：
Y. Takeuchi;S. Lin;T. Sasaki;M. Yano
中科院分区：
文献类型：
--
作者：
Y. Takeuchi;S. Lin;T. Sasaki;M. Yano
通过对日本晴和卡萨拉特回交自交系的区间定位，将种子休眠性（暂命名为Sdr1）和抽穗期（Hd8）两个数量性状基因座定位在第3染色体上的同一区域。为了阐明Sdr1和Hd8是否可以在遗传上进行解剖，我们用一个先进的回交后代进行了精细的定位。我们选择了一个BC4F1植株，其中第3染色体短臂上包括Sdr1和Hd8在内的一个小的染色体区域保持杂合，而所有其他染色体区域都是日本晴纯合的。BC_4F_2植株的抽穗天数和种子发芽率呈连续变异。根据限制性片段长度多态性（RFLP）标记的基因型选择了10个在Sdr1和Hd8附近发生重组的BC4F2植株。通过对BC4F4家系的后代检测，确定了Sdr1和Hd8的基因型，Sdr1定位在R10942和C2045之间，与C1488共分离，Hd8定位在C12534S和R10942之间。在Sdr1和Hd8之间检测到6个重组事件。这些结果清楚地表明Sdr1和Hd8紧密连锁。通过分子标记辅助选择，获得了Sdr1和Hd8的近等基因系。
Two quantitative trait loci (QTLs) for seed dormancy (tentatively designatedSdr1) and heading date (Hd8) have been mapped to approximately the same region on chromosome 3 by interval mapping of backcross inbred lines derived from crosses between the rice cultivars Nipponbare (japonica) and Kasalath (indica). To clarify whetherSdr1andHd8could be dissected genetically, we carried out fine-scale mapping with an advanced backcross progeny. We selected a BC4F1plant, in which a small chromosomal region includingSdr1andHd8, on the short arm of chromosome 3, remained heterozygous, whereas all the other chromosomal regions were homozygous for Nipponbare. Days-to-heading and seed germination rate in the BC4F2plants showed continuous variation. Ten BC4F2plants with recombination in the vicinity ofSdr1andHd8were selected on the basis of the genotypes of the restriction fragment length polymorphism (RFLP) markers flanking both QTLs. Genotypes of those plants forSdr1andHd8were determined by advanced progeny testing of BC4F4families.Sdr1was mapped between the RFLP markers R10942 and C2045, and co-segregated with C1488.Hd8was also mapped between C12534S and R10942. Six recombination events were detected betweenSdr1andHd8. These results clearly demonstrate thatSdr1andHd8were tightly linked. Nearly isogenic lines forSdr1andHd8were selected by marker-assisted selection.