中国农业科学 ›› 2023, Vol. 56 ›› Issue (21): 4219-4233.doi: 10.3864/j.issn.0578-1752.2023.21.007

• 植物保护 • 上一篇    下一篇

水稻Pi9位点6个稻瘟病抗性基因特异分子标记的开发及应用

杨好1(), 黄衍焱1(), 易春霖1, 石军2, 谭楮湉1, 任文芮1, 王文明1()   

  1. 1 四川农业大学西南作物基因资源发掘与利用国家重点实验室,成都 611130
    2 绵阳市农业科学研究院水稻研究所/厅市共建作物特色资源创制及应用四川省重点实验室,四川绵阳 621023
  • 收稿日期:2023-07-23 接受日期:2023-09-06 出版日期:2023-11-01 发布日期:2023-11-06
  • 通信作者:
    王文明,E-mail:
  • 联系方式: 杨好,E-mail:2365657091@qq.com。黄衍焱,E-mail:h1985yy@163.com。杨好和黄衍焱为同等贡献作者。
  • 基金资助:
    国家自然科学基金(U19A2033); 国家自然科学基金(31901839); 四川省青年科技创新研究团队(2022JDTD0023)

Development and Application of Specific Molecular Markers for Six Homologous Rice Blast Resistance Genes in Pi9 Locus of Rice

YANG Hao1(), HUANG YanYan1(), YI ChunLin1, SHI Jun2, TAN ChuTian1, REN WenRui1, WANG WenMing1()   

  1. 1 State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130
    2 Institute of Rice Research, Mianyang Academy of Agricultural Sciences/Crop Characteristic Resources Creation and Utilization Key Laboratory of Sichuan Province, Mianyang 621023, Sichuan
  • Received:2023-07-23 Accepted:2023-09-06 Published:2023-11-01 Online:2023-11-06

摘要:

【目的】水稻Pi9位点由多个串联的同源NLR基因组成,从中已克隆了超过10个优良的稻瘟病抗性基因。论文旨在鉴别水稻亲本Pi9位点抗性基因的组成,促进该位点基因快速、精准地应用于水稻抗性育种。【方法】对比Pi9位点已克隆抗性基因的序列,从中发掘各基因特异的核苷酸位点;然后将各目标基因分别与数据库(Rice Resource Center)中的155个水稻基因组进行比对分析,进一步从中筛选出特异最强的核苷酸位点,用于Pi2Piz-tPi9Pi9-type5PigmRPid4 6个抗性基因特异分子标记的开发;以24个抗稻瘟病单基因系、阳性对照和110个四川盆地水稻亲本为鉴定对象,通过优化PCR扩增条件、测序或基因组数据分析检验分子标记鉴定结果的准确性。由于该位点基因的同源性较高、基因间常常拥有一些相同的特异位点,导致许多抗性基因很难用一对分子标记进行精准鉴定,因此采用多对分子标记共同鉴定的方式;另外许多特异位点为单碱基差异,因此需要对差异位点旁的碱基进行特异突变,使引物的3′端具有两个碱基的错配,以提高PCR扩增的特异性。【结果】最终为6个Pi9位点的抗性基因开发了有效的分子标记,发现32.09%的参试水稻材料含有Pi9位点抗性基因。Pi9Pid4PigmRPiz-tPi2Pi9-type5分别存在于1、7、8、14、23和33个水稻材料中,其中Pi9仅存在于单基因系中。这些抗性基因通常两个或多个组合在一起,同时存在于一个水稻材料中。其中Pi9-type5往往与Pi2Piz-t成对出现,仅在成恢993、HR2168和绵恢365 3个亲本中单独存在。雨恢38含有的Pi9位点抗性基因最多,分别有Pi2Pi9-type5PigmRPid4。川谷B、川农4B、内香6B和双1B中均同时含有Piz-tPigmRPid4 3个抗性基因。千乡654B中含有Piz-tPid4两个抗性基因。【结论】为Pi9位点的6个同源稻瘟病抗性基因开发了特异的分子标记,明确了四川盆地110个水稻亲本Pi9位点的抗性基因组成,揭示了Pi9位点抗性基因丰富的组合形式,为水稻育种的抗原选择提供了明确参考。

关键词: 水稻, 稻瘟病, Pi9位点, 同源基因, 分子标记

Abstract:

【Objective】The Pi9 resistance gene locus, conferring a broad-spectrum resistance against Magnaporthe oryzae, is consist by several tandem homologous genes. Over 10 resistance genes have been cloned from this gene locus. This study aims to clarify the R gene composition at Pi9 locus in rice resource materials and promote the application of those genes in rice resistance breeding.【Method】Comparing the DNA sequence of cloned R genes at Pi9 locus, the specific nucleotide polymorphism sites were screened as the candidate sites. Subsequently, each R gene was blasted with 155 rice genomes in the database of Rice Resource Center. The most specific nucleotide polymorphism sites were picked out from the candidate site in each gene to develop primer pair of molecular markers. The PCR product of primer pairs was used to mark indicated R gene in tested rice materials via parameter optimization. To verify the results, the R genes were cloned from indicated rice variety randomly and examined by Sanger sequencing, or analyzed the R genes from the genome database if the genome sequence of indicated rice variety exists in Rice Resource Center. The R genes in Pi9 locus have high homology, which cause same specific nucleotide polymorphism sites existing in different R genes. Therefore, some R genes are hardly identified by one molecular marker. For this case, several molecular markers were employed to identify the indicated R gene simultaneously. Moreover, some specific nucleotide polymorphism sites are single nucleotide polymorphism (SNP), in where the primers of molecular markers have a mismatched base. In order to improve the specificity of PCR amplification, the adjacent base of SNP was mutated to generate two mismatched bases at 3′ site of primer.【Result】Finally, the valid molecular markers were developed for each R gene and identified 32.09% tested materials containing R genes at Pi9 locus. Pi9, Pid4, PigmR, Piz-t, Pi2 and Pi9-type5 are present in 1, 7, 8, 14, 23 and 33 tested materials, respectively. The Pi9 only presents in monogenic line but not in rice parent lines. The other genes are usually present in two or more gene combinations in rice parent lines. The Pi9-type5 often presents in pair with Pi2 and Piz-t, and presents alone in three rice parents, Chenghui 993, HR2168 and Mianhui 365. Yuhui 38 contains the most R genes at Pi9 locus, including Pi2, Pi9-type5, PigmR and Pid4. Chuangu B, Chuannong 4B, Neixiang 6B and Shuang 1B contain Piz-t, PigmR and Pid4. Qianxiang 654B contains Piz-t and Pid4.【Conclusion】This study successfully developed specific molecular markers for six homologous rice blast resistance genes in Pi9 locus and identified the R gene composition in Pi9 locus for 110 rice parent lines that used in rice breeding in Sichuan basin. It also discovered different types of R genes combination at Pi9 locus and provided a clear reference for choosing the resistance source in rice breeding.

Key words: rice, rice blast, Pi9 locus, homologous gene, molecular marker