空间诱变水稻重要性状的遗传与变异

Heredity and mutation of rice important characters by space mutation

【目的】研究空间诱变水稻后代重要性状的遗传与变异情况,为水稻空间诱变育种提供借鉴。【方法】利用返回式卫星搭载籼型水稻单株纯系品种广恢998、HR15、特B、湛B、双青B和II-32B的干种子,以各品种地面种子为对照,在相同条件下种植后,考察其后代(SP1~SP4代)主要经济性状(粒长、粒宽、穗粒数、千粒质量、单株粒质量、结实率)和农艺性状(株高、剑叶长、剑叶宽、穗数、穗长)的表现及其遗传变异情况。【结果】6个空间诱变水稻品种SP1代的大多数性状与各自地面对照差异不明显;而SP2代的主要农艺性状和经济性状则出现了正、反2个方向的强烈分离变异,各品种突变株主要性状的极差和变异系数均值均远大于其对照,还出现了特大粒、特大穗等特殊突变体,变异类型极为丰富;SP3代的性状大体与SP2代相似,SP2代中的突变性状大多在SP3代中重现;至SP4代时,大部分变异性状已基本稳定。【结论】水稻干种子在空间条件下所产生的变异,能稳定地遗传给后代;空间诱变育种可以成为一种新的水稻诱变育种方法。

[Objective] The research studied the heredity and mutation of rice important characters by space mutation to provide research reference for rice spaceflight breeding. [Method] The rice dry seeds of Guanghui998, HR15,TeB, ZhanB, ShuangqingB and II-32B were carried by recoverable satellite for space mutation,after recovery,the seeds were sowed in the same condition with check on the earth, the SP1--SP4 generation＇s major economic characters,including grain length, grain width, grains per spike, 1 000-seed weight, grain yield and setting rate,and the major agronomic characters of plant height, flag leaf length, flag leaf width, spike number and spike length and heredity and variation of their progenies were observed. [Result] Most characters were not significantly different between SP1 generation and the check. However,the main agronomic and economic characters of SP2 generation showed strong segregation and variation in the extreme;The major characters＇ average maximum value and variation coefficient of every kind^s mutational line were much bigger than check. There were outsized grain and spike in the SP2 generation. The mutation kinds were abundant. On the whole, the characters of SPa generation were the same with SP2 generation, and the most mutation characters of SP2 generation could be seen in the SPa generation. The most characters of SP4 generation were basically stable. [Conclusion] The variations induced by high space conditions are inherita- ble. Rice breeding by space mutation can be used as a new way of mutation breeding.