基于CSSL的高密度物理图谱定位水稻分蘖角度QTL

对以籼稻9311为遗传背景携带粳稻日本晴基因组的染色体片段置换系（CSSL）的遗传图谱进行分子标记加密,构建了含250个多态标记的高密度物理图谱。以119个CSSLs为材料,P≤0.001为阈值,筛选到分蘖角度与受体亲本9311差异极显著的10个系。结合物理图谱和代换作图方法,共鉴定出5个分蘖角度QTL,其中qTA11的加性效应表现为增效作用,来源于9311的等位基因;其余4个QTL的加性效应为减效作用,均来源于日本晴的等位基因。qTA6-1和qTA6-2分别被定位于第6染色体RM253–RM527之间的3.55Mb区段和RM3139–RM494的1.65Mb区间;qTA9被定位于第9染色体RM257–RM189之间的3.40Mb区段;qTA10被定位在第10染色体RM222–S10-1之间的2.10Mb区段;qTA11被定位于第11染色体RM1761–RM4504之间的3.30Mb区间。以上研究结果为水稻分蘖角度QTL的精细定位和株型育种提供了依据。

Identification of Tiller Angle Quantitative Trait Loci Based on Chromosome Segment Substituted Lines and High-density Physical Map in Rice

We developed a 9311/Nipponbare physical maP with 250 simple sequence repeat/sequence-tagged site markers by adding markers on the original genetic map. We screened 119 chromosome segment substituted lines and obtained 10 lines with significantly different tiller angle trait as compared with the recipient 9311 （P〈0.001）. From this physical map, we detected quantitative trait loci （QTL） using the substitution map strategy. We identified 5 tiller-angle QTL, with qTA11 showing a positive effect and derived from the 9311 allele. Additional 4 QTL had a negative effect and were all derived from Nipponbare alleles, qTA6-1 and qTA6-2 were located on chromosome 6 at 3.55 Mb between RM253 and RM527 and at 1.65 Mb between RM3139 and RM494, respectively; qTA9 was located on chromosome 9 at 3.40 Mb between RM257 and RM189; qTA 10 was located on chromosome 10 within 2.10 Mb between RM222 and S10-1; qTA 11 was located on chromosome 11 within 3.30 Mb between RM1761 and RM4504. These results provide useful information for fine mapping new QTL of tiller angle and for rice breeding by plant type.