对53个籼稻品种辐射M_2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M_2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。 The results showed that: (1) The frequency of precocious mutation was 1.4% on average, of which the late-mature varieties had a higher frequency of precocious mutation than the precocious varieties. And the growth of the original species was positively correlated with a correlation coefficient of 0.40. Mutants ranged from 3 to 32 days earlier, with an average of 9.5 days. They increase with the delay of the growth period. (2) In the same variety of radiation M_2 generations, early and late two-phase maturity mutations generally occur at the same time, and the mutation rate of the latter is higher than the former, which are 1.39% and 2.67% respectively. The number of days in which the mutants were earlier and delayed was basically close (11.5 vs 10.3 days). Early and late two-way mutants, due to the opposite direction of the maturity of their changes, and thus to some extent, plant height, grain number per spike, grain weight and other agronomic traits also occurred bidirectional mutation, and some even reached a significant level.