The Applied Plant Genomics Laboratory of Crop Genomics and Bioinformatics Centre, and National Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China.
Theor Appl Genet. 2010 Jun;121(1):147-56. doi: 10.1007/s00122-010-1298-5. Epub 2010 Mar 3.
Qfhi.nau-4B is a major quantitative trait locus (QTL) against Fusarium graminearum infection identified in the Fusarium head blight-resistant germplasm Wangshuibai. To fine map this QTL, a recombinant inbred line (RIL) population of 530 lines derived from Nanda2419 x Wangshuibai and the BC(3)F(2) population derived from the cross of a Qfhi.nau-4B near isogenic line (NIL) with susceptible cultivar Mianyang 99-323 as the recurrent parent were screened for recombinants occurred between microsatellite markers Xbarc20 and Xwmc349 that flank Qfhi.nau-4B. A total of 95 recombinants were obtained, including 45 RIL recombinants obtained through reverse-selection of Qfhi.nau-5A and 50 NIL recombinants from the BC(3)F(2) population. Genotyping these recombinant lines with 22 markers mapping to the Xbarc20 and Xwmc349 interval revealed fourteen genotypes of the RIL recombinants as well as of the NIL recombinants. Two-year field evaluation of their resistance to Fusarium infection showed that these lines could be clearly classified into two groups according to percentage of infected spikes. The more resistant class had over 60% less infection than the susceptible class and were common to have Wangshuibai chromatin in the 1.7-cM interval flanked by Xhbg226 and Xgwm149. None of the susceptible recombinants had this Wangshuibai chromatin. Qfhi.nau-4B was thus confined between Xhbg226 and Xgwm149 and named Fhb4. The interval harboring Fhb4 was mapped to 4BL5-0.86-1.00 bin using Chinese Spring deletion lines, a region with about 5.7 times higher recombination rate than the genome average. This study established the basis for map-based cloning of Fhb4.
Qfhi.nau-4B 是在抗赤霉病品种 Wangshuibai 中鉴定的一个针对禾谷镰刀菌感染的主要数量性状位点 (QTL)。为了精细定位这个 QTL，我们从 Nanda2419 x Wangshuibai 衍生的 530 个重组自交系 (RIL)群体和交叉近等基因系 (NIL)与易感品种绵阳 99-323 的 BC(3)F(2)群体中筛选出 Xbarc20 和 Xwmc349 微卫星标记之间发生重组的个体。总共获得了 95 个重组体，其中包括通过反向选择 Qfhi.nau-5A 获得的 45 个 RIL 重组体和来自 BC(3)F(2)群体的 50 个 NIL 重组体。用 22 个标记对这些重组系进行基因型分析，这些标记位于 Xbarc20 和 Xwmc349 区间，结果表明 RIL 重组体和 NIL 重组体共有 14 种基因型。对其进行两年田间赤霉病感染抗性评价发现，根据感病穗的百分率，这些系可以明显分为两组。更具抗性的一组比易感组的感染率低 60%以上，并且在 Xhbg226 和 Xgwm149 之间的 1.7cM 区间内有 Wangshuibai 染色质。没有易感的重组体有这种 Wangshuibai 染色质。因此，Qfhi.nau-4B 被限定在 Xhbg226 和 Xgwm149 之间，并命名为 Fhb4。利用中国春缺失系，将包含 Fhb4 的区间定位到 4BL5-0.86-1.00 -bin，该区间的重组率约为基因组平均水平的 5.7 倍。这项研究为 Fhb4 的图谱克隆奠定了基础。
