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.