N^7＋重离子注入和贯穿后小麦种胚的期外DNA合成效应

用＾３ＨＴｄＲ掺入法研究了经Ｎ＾７＋重离子注入贯穿处理的８２５７９小麦和８８１２小麦种胚的ＤＮＡ合成动态。结果发现，未经Ｎ＾７＋重离子任何处理的两个小麦品种的对照种胚，在萌发早期（２０ｈ内）仅存在一个ＤＮＡ合成峰（于萌发的第１４ｈ），而经过Ｎ＾７＋重离子注入和贯穿处理的小麦种胚则存在两个ＤＮＡ合成峰（分别于萌发的８－１０ｈ和１４－１６ｈ），该种子经ＤＮＡ修复合成的抑制剂咖啡因处理后，第一个ＤＮＡ合

EFFECT OF UNSCHEDULED DNA SYNTHESTS IN SEED EMBRYOS OF WHEAT INJECTED AND PENETRATED BY N~(7+) HEAVY ION

The effect of unscheduled DNA synthesis (UDS) in seed embryos of wheat afterN7+ heavy ion injection and penetration hase been studied by 3H-TdR incorporationmethods. The experimental materials are dry seeds of cultivar 8812 and 82579 of wheat (Triticum aestivum L, ). The untreated normal seed embryos of two strains of wheat all show a peak of DNA synthesis during early germination (within 20 h) of them,the peak is at the 8th hour of germination of seed embryos. Whereas the seed embryos with N7+heavy ion injection and penetration show two peaks of DNA synthesis,the peaks are at 8- 10th and 14- 16th hour of germination of the seed embryos, respectively. When theseeds treated with N7+ heavy ion are futher treated by caffeine which is inhibitor of DNA repair synthesis,the peak of DNA synthesis occurred at 8- 10th hour of the seeds ger-mination disapear. It indicat that there is a effect of DNA synthesis or UDS during early germination in seed embryos of wheat injected and penetrated by N7+ heavy ion. TheUDS effect of seed embryos injected by N7+ heavy ion is lower than that of penetrated byN7+. The possible reason is discussed in the paper.