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筛选低Cd积累水稻品种是控制稻米Cd含量的最直接有效的办法之一。本研究对重离子辐照的中籼9311(Oryza sativa L)后代,利用石墨炉原子吸收光谱法检测,对曝露在不同Cd含量(含Cd量为19.8mg·kg~(-1)镉池和含Cd量为2.721 mg·kg~(-1)的污染农田)中进行M2代Cd低吸收突变单株筛选,研究重离子辐照水稻籽粒Cd吸收的突变率以及比较不同Cd含量曝露下的筛选效率。结果显示:重离子辐照可以诱发水稻籽粒Cd积累量的变异,其突变频率为3.398%±0.009(P<0.05);初筛获得78株籽粒较WT Cd吸收差异显著的突变体,进一步对其种植,分析M3代籽粒Cd含量。结果表明,重离子辐照诱变水稻突变体突变率高,遗传稳定,高Cd含量曝露下筛选效率更高,突变体水稻籽粒中Cd的积累存在着明显的差异,产生Cd积累差异的基因型丰富;相关性分析表明,M2代和M3代糙米中Cd含量存在显著相关性r=0.8210(P<0.01),M3代获得23株遗传性良好且Cd含量差异显著的突变体水稻,其中Cd含量低于国家标准0.2 mg·kg-1突变体3株。表明筛选出的水稻突变体,在吸收转运Cd的过程中,存在差异且能稳定遗传,可供进一步研究培育籽粒Cd低积累的水稻品种。
Screening low Cd accumulating rice varieties is one of the most direct and effective ways to control Cd content in rice. In this study, heavy ion irradiation of indica 9311 (Oryza sativa L) progeny, using graphite furnace atomic absorption spectrometry to detect, exposed to different Cd content (Cd content of 19.8 mg · kg -1 Cd pool and Cd-contaminated farmland with Cd content of 2.721 mg · kg -1) were selected to screen for low-absorption Cd-tolerant single plants of M2 generation, and to study the mutation rate of Cd uptake by heavy ion-irradiated rice grains and to compare the Cd exposure under different exposure conditions effectiveness. The results showed that heavy metal irradiation could induce the variation of Cd accumulation in rice grains with the mutation frequency of 3.398% ± 0.009 (P <0.05). 78 mutants with significant differences in WT Cd uptake were obtained by screening, Planting, analysis of M3 grain Cd content. The results showed that the mutagenesis rate of mutants induced by heavy ion irradiation was high, the genetic stability was high, and the screening efficiency was higher under the exposure of high Cd content. The Cd accumulation in the mutant rice had obvious difference, and the genotype Correlation analysis showed that there was a significant correlation between Cd content of M2 generation and M3 brown rice (r = 0.8210 (P <0.01)), and that of M3 generation was significantly higher than those of other rice cultivars Lower than the national standard 0.2 mg · kg-1 mutant 3. The results showed that the selected rice mutants were stable and stable in absorbing and transporting Cd, which could be used for further research on cultivating rice varieties with low Cd accumulation.