Biological Effects of Autotetraploid Rice after Ion Beam Implantation of Low Energy N~+

Biological effects of autotetraploid rice after ion beam implantation of low energy N+ were studied. The results showed that autotetraploid rice were more sensitive to the ion beam implantation than diploid rice. Autotetraploid rice were more severely damaged when the dosage was 3×1017 N+/cm2. The frequencies of surviual plant from the autotetraploid rice, IR36(4)?IR28(4)?Zixuedao(4) and Minghui63(4), were individually 2.0%?3.5%?3.0% and 4.0%,but the numbers from the 4 diploid rice, IR36(2)?IR28(2)?Zixuedao(2) and Minghui63(2), were individually 33.0%?31.5%?29.0% and 24.5%. In the populations conducted by N+, autotetraploid rice(32.5%) showed higher mutagenic frequency than diploid rice(9.5 %). See sets of the 22 plants from IR36(4) and the 14 plants from IR28(4) surpassed 75.0%.The one mutagenic plant from IR36(4) was 91.89% in setting percentage. The two plants with the doubleembryo seedlings were successfully found in Zixuedao(4). The 1 plant with red rice character was selected in Minghui63(2). In the second population, all mutagenic characters expressed obvious characteristics of separation except the two characters (leaf sheath and rice). The higher seesets and the doubleembryo seedlings in Zixuedao(4) showed obviously to be geneticable in subsequent generations