Liu X Q, Wang L, Chen S, Lin F, Pan Q H
Laboratory of Plant Resistance and Genetics, College of Natural Resources and Environmental Sciences, South China Agricultural University, Guangzhou, 510642, China.
Mol Genet Genomics. 2005 Nov;274(4):394-401. doi: 10.1007/s00438-005-0032-5. Epub 2005 Sep 7.
Blast resistance in the indica cultivar (cv.) Q61 was inherited as a single dominant gene in two F2 populations, F2-1 and F2-2, derived from crosses between the donor cv. and two susceptible japonica cvs. Aichi Asahi and Lijiangxintuanheigu (LTH), respectively. To rapidly determine the chromosomal location of the resistance (R) gene detected in Q61, random amplified polymorphic DNA (RAPD) analysis was performed in the F2-1 population using bulked-segregant analysis (BSA) in combination with recessive-class analysis (RCA). One of the three linked markers identified, BA1126(550), was cloned and sequenced. The R gene locus was roughly mapped on rice chromosome 8 by comparison of the BA1126(550) sequence with rice sequences in the databases (chromosome landing). To confirm this finding, seven known markers, including four sequence-tagged-site (STS) markers and three simple-sequence repeat (SSR) markers flanking BA1126(550) on chromosome 8, were subjected to linkage analysis in the two F2 populations. The locus was mapped to a 5.8 cM interval bounded by RM5647 and RM8018 on the short arm of chromosome 8. This novel R gene is therefore tentatively designated as Pi36(t). For fine mapping of the Pi36(t) locus, five additional markers including one STS marker and four candidate resistance gene (CRG) markers were developed in the target region, based on the genomic sequence of the corresponding region of the reference japonica cv. Nipponbare. The Pi36(t) locus was finally localized to an interval of about 0.6 cM flanked by the markers RM5647 and CRG2, and co-segregated with the markers CRG3 and CRG4. To physically map this locus, the Pi36(t)-linked markers were mapped by electronic hybridization to bacterial artificial chromosome (BAC) or P1 artificial chromosome (PAC) clones of Nipponbare, and a contig map was constructed in silico through Pairwise BLAST analysis. The Pi36(t) locus was physically delimited to an interval of about 17.0 kb, based on the genomic sequence of Nipponbare.
籼稻品种Q61的抗稻瘟病性在两个F2群体F2 - 1和F2 - 2中表现为单个显性基因遗传,这两个群体分别来自供体品种与两个感病粳稻品种爱知旭和丽江新团黑谷(LTH)的杂交。为了快速确定在Q61中检测到的抗性(R)基因的染色体位置,在F2 - 1群体中利用混合分组分析法(BSA)结合隐性类分析法(RCA)进行了随机扩增多态性DNA(RAPD)分析。鉴定出的三个连锁标记之一BA1126(550)被克隆并测序。通过将BA1126(550)序列与数据库中的水稻序列进行比较(染色体登陆),将R基因座大致定位在水稻第8号染色体上。为了证实这一发现,对包括四个序列标签位点(STS)标记和三个位于第8号染色体上BA1126(550)侧翼的简单序列重复(SSR)标记在内的七个已知标记在两个F2群体中进行了连锁分析。该基因座被定位在第8号染色体短臂上由RM5647和RM8018界定的5.8 cM区间内。因此,这个新的R基因暂时命名为Pi36(t)。为了对Pi36(t)基因座进行精细定位,基于参考粳稻品种日本晴相应区域的基因组序列,在目标区域开发了另外五个标记,包括一个STS标记和四个候选抗性基因(CRG)标记。Pi36(t)基因座最终定位在由标记RM5647和CRG2侧翼的约0.6 cM区间内,并与标记CRG3和CRG4共分离。为了对该基因座进行物理定位,将与Pi36(t)连锁的标记通过电子杂交定位到日本晴的细菌人工染色体(BAC)或P1人工染色体(PAC)克隆上,并通过成对BLAST分析在计算机上构建了重叠群图谱。基于日本晴的基因组序列,Pi36(t)基因座在物理上被限定在约17.0 kb的区间内。