【摘要】 对53个籼稻品种辐射M₂代进行连续三年的试验,结果表明:（1）早熟突变频率平均为1.4％,其中迟熟类型品种要比早熟类型品种有更高的早熟突变频率。并与原品种的生育期呈正相关,相关系数为0.40。突变体提早的范围为3～32天,平均为9.5天。它们是随生育期的推迟而增加。（2）在同一品种的辐射M₂代中,一般可同时出现早、晚双向熟期的突变,且后者的突变率高于前者,分别为1.39％和2.67％。突变体提早和延迟的天数两者基本接近（11.5对10.3天）。早、晚双向突变体,由于其熟期发生了相反方向的改变,因而在一定程度上,株高、每穗粒数、千粒重等农艺性状也发生了双向变异,有些甚至达到显著水平。更多还原

【Abstract】 After three years of consecutive experiments for the irradiated M2 generations of 53 different varieties of rice, the following results have been obtained; (l)The average of early mutant plant rate is 1. 4%. The rate in the early-maturing varieties is lower than that in the late-maturing varieties. It is in proportion to the length of growing period of these varieties tested. The shortened days of growing period of early mutants are 3 to 32 days (the average was 9. 5 days), and it is increasing as the growing period increases. (2)In the irradiated M2 generation of same variety, the early mutants and late mutants could be simultaneously happened,but the rate of the late mutants is 2. 67% that is higher than the rate of early mutants (1. 39%). The shortened and prolonged days of growing period are 11. 5 and 10. 5 days respectively. These early and late mutants have some changes, both good and bad, in agronomical traits such as plant height, weight per kilo-grains and grains number per tassel. In some extent these changes are significant.更多还原