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将加速器7Li+ 3 离子束与生物体内遗传物质发生1H( 7Li,7Be)n内靶特征核反应诱发核酸分子结构变化的机制应用于生物诱变 ,辐照剂量在 1 41 6× 1 0 10 粒子 cm2 - 1 41 6× 1 0 12 粒子 cm2范围内处理的小麦 ,观察幼苗叶片细胞亚显微结构 ,发现离子束注入引起了细胞膜的破裂 ,细胞发生质壁分离 ,细胞核形状变得不规则等。出现叶绿体局部突起 ,形成芽状结构 ;叶绿体基粒排列散乱 ,基粒类囊体模糊不清 ;叶绿体膜破裂 ,甚至消失 ;线粒体出现脊模糊、破裂等变化。对幼苗根尖细胞学研究观察 ,获得单桥、双桥、桥断裂、落后染色体、三级、断片和微核等畸变类型 ;对已获得的小麦突变株 ,分别进行M2 代DNA分子的RAPD分析 ,结果发现DNA均发生变异 ,证明7Li+ 3 注入通过内靶核反应能够诱发小麦在分子水平上产生遗传变异。
The mechanism of the structural change of nucleic acid molecules induced by the reaction of 7Li + 3 ion beam with the target characteristic 1H (7Li, 7Be) n in biological material in vivo was applied to biological mutagenesis at irradiation dose of 1 41 6 × 10 10 particles cm 2 - 1 41 6 × 10-12 particles cm2 treatment of wheat, observe the seedling leaf cells sub-microstructure and found that ion beam injection caused cell membrane rupture, cell wall plasmolysis, the nucleus became irregular shape and so on. Some chloroplast local prominence, the formation of bud-like structure; chloroplast scattered arrangement of basal grains, granallocystis fuzzy; chloroplast membrane rupture, or even disappear; mitochondria ridge blur, rupture and other changes. The root tips of seedling cells were observed and the aberration types of single bridge, double bridge, bridge break, backward chromosome, third stage, fragment and micronucleus were obtained. The RAPD analysis of M2 generation DNA molecules The results showed that DNA was mutated. It was demonstrated that 7Li + 3 injection induced the genetic variation of wheat at the molecular level through internal target nuclear reaction.