重离子辐射诱导水稻花粉母细胞染色体畸变的研究

分别用高能重离子４０Ａｒ，５６Ｆｅ，与６０Ｃｏ－γ射线照射水稻边皮占干种子，观察Ｍ１，Ｍ２的发长发充及花粉母细胞减数分裂各时期出现的染色体畸变。结果表明Ｍ１结实率与染色体畸变率均与辐射剂量显著相关。重离子辐射比γ射线更有效减少结实率及诱导染色体畸变，Ｍ１成苗率与结实率及Ｍ１，Ｍ２花粉母细胞染色体畸变率的相对生物学效应值均大于１。Ｍ２花粉母细胞染色体畸变率较低，但仍与剂量呈线性关系，且γ射线诱导畸变

CHROMOSOME ABERRATIN OF POLLEN MOTHER CELS OF RICE INDUCED BY HEAVY ION RADIATION

The effects on growth,development and meiotic chromosome of pollenmo ther cells induced by three types of radiation with different LET were investigatedafter rice seeds were irradiated with these radiations.The results sho wed that the sur-vival rates,setting rates in the first generation,and the chromosome aberration ratesin the first and second generation all were dose-dependent.High LET heavy ionbeanis,e.g.40Ar or 56Fe ions,were more effective than that of low LET60Co-gammarays in inducing these effects.Compared with the corresponding chromosomeaberration rates in the first generation,all the chromosome aberration rates observedin the second generation were smaller,ho wever,those induced by heavy ions declinedless than that of gamma rays,indicating the damage on genetic materials caused byhigh LET heavy ions was less reparable than that by low LET gamma rays.