Laboratory of Plant Resistance and Genetics, College of Natural Resources and Environment Sciences, South China Agricultural University, Guangzhou 510642, China.
Sci China Life Sci. 2011 Apr;54(4):372-8. doi: 10.1007/s11427-011-4154-1. Epub 2011 Mar 4.
Blast, caused by Magnaporthe oryzae, is one of the most widespread and destructive diseases of rice. Breeding durable resistant cultivars (cvs) can be achieved by pyramiding of various resistance (R) genes. Pia, carried by cv. Aichi Asahi, was evaluated against 612 isolates of M. oryzae collected from 10 Chinese provinces. The Pia gene expresses weak resistance in all the provinces except for Jiangsu. Genomic position-ready marker-based linkage analysis was carried out in a mapping population consisting of 800 F(2) plants derived from a cross of Aichi Asahi×Kasalath. The locus was defined in an interval of approximately 90 kb, flanked by markers A16 and A21. Four candidate genes (Pia-1, Pia-2, Pia-3, and Pia-4), all having the R gene conserved structure, were predicted in the interval using the cv. Nipponbare genomic sequence. Four candidate resistance gene (CRG) markers (A17, A25, A26, and A27), derived from the four candidates, were subjected to genotyping with the recombinants detected at the flanking markers. The first three markers completely co-segregated with the Pia locus, and the fourth was absent in the Aichi Asahi genome and disordered with the Pia locus and its flanking markers, indicating that the fourth candidate gene, Pia-4, could be excluded. Co-segregation marker-based genotyping of the three sets of differentials with known R gene genotypes revealed that the genotype of A26 (Pia-3) perfectly matched the R gene genotype of Pia, indicating that Pia-3 is the strongest candidate gene for Pia.
稻瘟病是由稻瘟病菌引起的，是水稻最广泛和最具破坏性的疾病之一。通过各种抗性（R）基因的聚合，可以培育出持久抗性的品种（ cvs ）。携带 cv. Aichi Asahi 的 Pia 在来自中国 10 个省的 612 个稻瘟病菌分离株中进行了评估。除江苏外，Pia 基因在所有省份均表现出弱抗性。在一个由 Aichi Asahi×Kasalath 杂交产生的 800 个 F2 植物群体中进行了基于基因组位置准备标记的连锁分析。该基因座被定义在大约 90kb 的区间内，由标记 A16 和 A21 侧翼。在该区间内，使用 cv. Nipponbare 基因组序列预测了 4 个候选基因（Pia-1、Pia-2、Pia-3 和 Pia-4），它们都具有 R 基因保守结构。从这 4 个候选基因中衍生出的 4 个候选抗性基因（CRG）标记（A17、A25、A26 和 A27），在侧翼标记检测到的重组体上进行了基因分型。前三个标记与 Pia 基因座完全连锁，第四个标记在 Aichi Asahi 基因组中缺失，与 Pia 基因座及其侧翼标记混乱，表明第四个候选基因 Pia-4 可以排除。用已知 R 基因基因型的三组不同材料的共分离标记进行基因分型，结果表明 A26（Pia-3）的基因型与 Pia 的 R 基因基因型完全匹配，表明 Pia-3 是 Pia 的最强候选基因。
