Identification and molecular mapping of the rice bacterial blight resistance gene allelic to Xa7 from an elite restorer line Zhenhui 084
Identification and molecular mapping of the rice bacterial blight resistance gene allelic to Xa7 from an elite restorer line Zhenhui 084
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DOI：
10.1007/s10658-009-9478-3
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发表时间：
2009-05
影响因子：
1.8
通讯作者：
Yuchen Zhang;Jianfei Wang;Jianwei Pan;Zhi-min Gu;Xifeng Chen;Yang Jin;Feng Liu;Hongsheng Zhang;B. Ma
中科院分区：
文献类型：
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作者：
Yuchen Zhang;Jianfei Wang;Jianwei Pan;Zhi-min Gu;Xifeng Chen;Yang Jin;Feng Liu;Hongsheng Zhang;B. Ma
水稻白叶枯病是由水稻黄单胞菌（Xanthomonasoryzaepv.Orychidae，Xoo）引起的一种严重的水稻病害。粳稻品种新育成的强籼恢复系珍恢084对菲律宾大部分BB小种表现高抗，已在我国杂交水稻中广泛应用，但其抗病基因尚未克隆。本研究表明，珍恢084对Xoo菌株的抗性与IRBB7相似，IRBB7含有Xa7，这是一个持久的、广泛的抗BB显性基因。为定位镇恢084的抗病基因，以成恢448和镇恢084为材料，构建了由331个高感单株组成的F2群体。我们将目标R基因精细定位到水稻第6染色体上两个邻近标记RM20576和MY4之间的区域。基于标记的6号染色体物理图谱用于构建覆盖两个标记RM20576和MY4之间的基因组区域的重叠群。假设靶基因在约200 kb的区间内，其中预测了16个候选基因。我们的研究结果将极大地促进目标R基因等位基因Xa7的分离和表征。此外，两个基于PCR的标记，紧密连锁的目标R基因位点，将是一个有用的工具，标记辅助选择的目标R基因的等位基因Xa7在育种计划。
Rice bacterial blight (BB), caused byXanthomonas oryzaepv.Oryzae (Xoo), is a serious disease in rice production worldwide. Rice cv. Zhenhui 084, a newly developed strong indica restorer line, exhibits high resistance to most of the Philippine races of BB and has been widely used in rice hybrids in China; however, the resistance gene has not yet been cloned. Here, we show that the resistance of Zhenhui 084 toXoostrains is similar to that of IRBB7 containingXa7, a durable and broad resistance dominant gene for BB. To map the resistance gene in Zhenhui 084, a F2population with 331 highly susceptible individuals derived from a cross between Chenghui 448 and Zhenhui 084 was built. We finely mapped the target R gene to a region between two proximal markers RM20576 and MY4 in rice chromosome 6. A marker-based physical map of chromosome six was used to construct the contig covering the genomic region between two markers RM20576 and MY4. The target gene was assumed to be in an interval of approximate 200 kb, in which 16 candidate genes were predicted. Our findings will greatly facilitate the isolation and characterisation of the target R gene allelic toXa7. Additionally, two PCR-based markers, tightly linked to the target R gene locus, will be a useful tool for the marker-assisted selection of the target R gene allelic toXa7in breeding programmes.