水稻空间诱变与重离子诱变萌发期耐盐突变体的筛选与鉴定

    Screening and identification of salt-tolerant mutants at germination stage from space mutagenesis and heavy ion radiation of rice

    • 摘要:
      目的 筛选萌发期耐盐突变体,为耐盐水稻新品种的创制与培育提供优异的种质资源。
      方法 对优质籼稻品种‘航聚香丝苗’干种子进行空间诱变或重离子诱变处理,并对诱变后代进行耐盐突变体的定向筛选。将野生型(WT)‘航聚香丝苗’种子用不同浓度NaCl进行处理,探索萌发期耐盐突变体筛选的适宜浓度,进而以发芽率为指标对5 205份M2诱变材料进行筛选,并在M3代进行验证。对野生型和突变体进行耐盐相关生理指标的测定与分析、农艺性状的考查;采用48个SSR标记对诱变后代与野生型的遗传相似性进行评估。
      结果 萌发期耐盐突变体筛选的适宜NaCl浓度为340 mmol/L,筛选得到12份萌发期耐盐突变体。生理指标测定结果显示,2个代表性突变体9-8和22-7的SOD、POD、CAT、APX活性均显著高于WT,MDA、H2O2和O2−含量均显著低于WT,耐盐突变体呈现出更强的抗氧化能力。农艺性状调查结果显示,突变体和野生型的农艺性状基本一致。SSR标记检测结果表明,野生型‘航聚香丝苗’与19-49、20-15、20-49、20-62、15-6、16-65、22-7、20-19、20-38均无SSR差异位点,与9-8、19-18、42-113的差异SSR位点均为1个。
      结论 本研究筛选到12份萌发期耐盐突变体,与野生型‘航聚香丝苗’的遗传背景高度一致,对水稻抗盐新品种的培育及抗盐性遗传机理的研究具有一定的理论和实际意义。

       

      Abstract:
      Objective To screen salt-tolerant mutants during germination, provide excellent germplasm resources for creating and breeding new salt-tolerant rice varieties.
      Method The dried seeds of the high quality indica rice variety ‘Hangjuxiangsimiao’, were treated with spatial mutagenesis and heavy ion mutagenesis, and the mutagenised progeny were subjected to targeted screening for salt-tolerant mutants. Wild type (WT) ‘Hangjuxiangsimiao’ seeds were treated with different concentrations of NaCl solution to explore the appropriate concentration for screening salt-tolerant mutants at the germination stage, and then 5 205 M2 mutant materials were screened using germination rate as an index and verified in the M3 generation. The wild type and mutants were measured and analysed for salt-tolerance-related physiological indices and agronomic traits; 48 SSR markers were used to assess the genetic similarity between the mutant progeny and the wild type.
      Result The appropriate NaCl concentration for screening salt-tolerant mutants at the germination stage was 340 mmol/L, and 12 salt-tolerant mutants were screened at the germination stage. The results of physiological indices showed that the SOD, POD, CAT and APX activities of two representative mutants 9-8 and 22-7 were significantly higher than those of WT, and the MDA, H2O2 and O2− contents were significantly lower, the salt-tolerant mutants exhibited stronger antioxidant capacity. The results of SSR marker detection showed that there were no SSR differentiation loci between the wild-type ‘Hangjuxiangsimiao’ seedlings and 19-49, 20-15, 20-49, 20-62, 15-6, 16-65, 22-7, 20-19 and 20-38, and one differentiation SSR loci between them and 9-8, 19-18, 42-113.
      Conclusion In this study, 12 salt-tolerant mutants were screened at the germination stage, which were highly consistent with the genetic background of wild-type ‘Hangjuxiangsimiao’. It has certain theoretical and practical significance for the breeding of new salt-tolerant rice varieties and the study of the genetic mechanism of salt tolerance.

       

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