水稻空间诱变与重离子诱变生物学效应及突变体定向筛选

    Biological effect and targeted mutation screening of space-induced mutagenesis and heavy ion radiation in rice

    • 摘要:
      目的  从不同诱变世代比较空间诱变和重离子诱变对水稻生物学效应及后代变异频率的差异,为水稻诱变育种提供一定的方法和理论指导。
      方法  对水稻纯系品种‘华航31号’干种子进行空间诱变和不同剂量重离子诱变处理,以未诱变处理的种子为对照,对诱变一代进行表型及细胞学诱变效应的分析;对诱变二代直链淀粉含量及粒型性状进行表型和基因型定向筛选,比较2种诱变处理的性状变异频率。
      结果  空间诱变一代的种子活力指数比对照下降了14.62%;重离子诱变一代的种子活力指数随辐射剂量增加呈现马鞍型效应曲线,其中10 Gy重离子辐射剂量下种子活力指数比对照下降了14.92%,与空间诱变的诱变效应相近。空间诱变二代粒型和直链淀粉含量的突变频率分别为4.14%和1.61%,80 Gy重离子辐射诱变二代粒型和直链淀粉含量的突变频率分别为4.88%和1.55%。利用HRM技术扫描了水稻直链淀粉含量Wx基因的4个位点共673 bp序列,在空间诱变的4 736份样本中发现3个SNP变异,突变密度为1/1063.83 kb;在重离子诱变4 848份样本中发现4个SNP变异,突变密度为1/815.68 kb。
      结论  2种诱变处理均可诱发水稻产生性状变异。空间诱变的生理损伤类似于低剂量重离子辐射,而诱发变异的频率与高剂量重离子辐射相近。

       

      Abstract:
      Objective  To compare the biological effects and variation frequency of two mutagenesis methods, including space mutation and heavy ion radiation, in different generations of rice (Oryza sativa L.), and provide some methods and theoretical guidances for rice mutation breeding.
      Method  The dry seeds of pure line rice variety ‘Huahang 31’ were treated using space mutation and different dose of heavy ion radiation, and the seeds without mutation treatment were used as the control. The phenotypic and cytological mutagenic effects of the 1st generation of mutation (M1) were analyzed. The amylose content and grain shape trait of the 2nd generation of mutation (M2) were screened by phenotypic and genotypic targeted screening. The variation frequencies in M2 of two mutation treatments were compared.
      Result  The seed vigor index of space mutation M1 was 14.62% lower than that of the control. The seed vigor index of heavy ion radiation M1 showed a saddle effect curve with the increase of radiation dose, and the seed vigor index of 10 Gy heavy ion radiation M1 was 14.92% lower than that of the control which was like the mutation effect of space mutation. The grain type and amylose content mutation frequencies of space-induced M2 were 4.14% and 1.61% respectively, while the grain type and amylose content mutation frequencies of 80 Gy heavy ion radiation were 4.88% and 1.55% respectively. When HRM technology was used to scan the 673 bp sequences of four intervals of Wx gene, three SNP mutations were found in 4 736 samples of space-induced with a mutation density of 1/1063.83 kb. Four SNP mutations were found in 4 848 samples of heavy ion radiation with a mutation density of 1/815.68 kb.
      Conclusion  Two kinds of mutagenic treatments can induce the character variations of rice. The physiological effects of space-induced mutagenesis M1 is similar to low-dose heavy ion radiation, and the mutation frequency of M2 is similar to high-dose heavy ion radiation.

       

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