ALS抑制剂类除草剂抗性水稻功能标记的开发与验证

【目的】培育具有乙酰乳酸合酶(ALS)抑制剂类除草剂抗性的品种是防治水稻直播田杂草危害最经济、有效的途径之一,而利用分子标记辅助选择有助于提高其品种选择效率。【方法】在明确除草剂抗性突变体黄华占M-1 ALS基因编码区碱基差异的基础上,利用四引物扩增受阻突变体系PCR(Tetra-primer ARMS-PCR)技术,设计引物对不同品种(品系)和淮稻5号/黄华占M-1的F₂群体进行基因型检测,并结合除草剂的田间试验对标记的准确性进行验证。【结果】ALS基因编码区序列比对分析表明,尽管籼、粳稻之间具有多处差异碱基,但只有第1642和1643碱基TG到AT的变异能导致位于高度保守域的第548位编码氨基酸由色氨酸突变为甲硫氨酸,进而使水稻产生对ALS抑制剂类除草剂的抗性。依据PCR扩增产物的电泳带型,可以准确区分出3种不同的基因型,其基因型与苗期除草剂抗性的表型完全一致。【结论】利用Tetra-primer ARMS-PCR技术,可以实现对两个连续变异碱基位点基因型的快速检测,从而加快ALS抑制剂类除草剂抗性水稻品种的选育进程。

Development and Verification of a Functional Marker Associated with Resistance to ALS Inhibitor Herbicide

【Objective】Breedingrice varieties with resistance to ALS-inhibiting herbicide is the mosteconomical and effective method to preventweeds in direct-sowing field, and molecular marker-assisted selection canimprove its efficiency. 【Method】The dominant molecular marker, designed for genotypic detection in different varieties and an F₂ population derived fromHuaidao5/Huanghuazhan M-1(mutant with resistance to ALS-inhibiting herbicide) was developed with Tetra-primer ARMS-PCR technique, based on the clarified mutation in CDS of ALS gene. 【Result】 The sequence alignment analysis of ALS gene encoding regionshowed that only the mutation from T₁₆₄₂G₁₆₄₃ to A₁₆₄₂T₁₆₄₃ leading to the 548th amino acid substitutionfrom tryptophan to methioninein highly conserved regionwas the critical factors to produce resistance to ALS-inhibiting herbicide inHuanghuazhan M-1, despitethe existence of multiplebase differencesbetween different indica and japonica rice varieties.The results of PCR detection indicated that three different genotypescould be accurately distinguished by electrophoretic bands, and it was exactly consistent with the phenotype of herbicide resistance at the seedling stage. 【Conclusion】 The genotype associated with two continuous base mutations could be rapidly detected by Tetra-primer ARMS-PCRtechnique, and the efficiency for varieties with resistance to ALS-inhibiting herbicidecould be improved in breeding process.