Abstract: Air-dried seeds of indica rice variety Zhe 9248 were carried by recoverable satellite (RS) for space mutation. Mutagenic effects of outer space environment (OSE) of 175-354 km above sea level on rice plant were studied. Results showed that the germination percentage of the seeds and characters of SP₁ generation had no evident change. Segregation of major characters such as plant height,growth period duration(GPD),length of panicle,1000-grain weight and so on,appeared in the SP₂ generation resulting from RS. Mutant line Zhe 101 selected from the mutant progenies showed significant improvement in GPD,disease resistance and yield. Resistance to the blast and bacterial leaf blight disease was tested by inoculating the mutant with 20 strains of Magnaporthe grisea artificially from six blast regions, and dominant pathotype Ⅳ of Xanthomonas campestris pv. oryzae in Zhejiang Province. The average resistance scales were only 1.4 and 1.7 for leaf blast,and 1.6 and 1 3 for neck node blast, in 2001 and 2002 respectively. The average scale of bacterial leaf blight disease resistance was 1.4 in 2002. The mutant line Zhe 101 was resistant to 14 blast fungus strains. The rate of blast resistance for Zhe 101 was higher than that of its parent and CK. The mutant is likely to be used in breeding for variety improvement.

Key words: space environment, rice blast, bacterial leaf blight, disease resistance, rice, mutant, mutation breeding

摘要： 早籼浙9248经卫星搭载诱变处理，种子的发芽率及当代植株的性状均没有明显的变化，但对秧苗的生长表现出一定的刺激作用；SP2在株高、生育期、穗长、每穗粒数、千粒重、结实率及抗病性等性状上出现了较大的分离。经病区多代筛选培育成的突变体浙101，在熟期、抗病性和产量等性状上比原亲本有明显改良，2001~2002年经浙江省多点稻瘟病和白叶枯病联合鉴定，叶瘟平均级分别为1.4和1.7级，最高级为5.0级；穗瘟平均级分别为1.6和1.3级，最高级为3.0级；抗谱频率分别为70%和60%；对白叶枯病抗性平均级为1.4级，最高级为5.0级。抗病性比原亲本和对照有显著提高。试验表明，浙101是一个高抗稻瘟病兼抗白叶枯病的水稻突变体，可作为水稻品种改良的新抗源。

关键词: 空间环境, 稻瘟病, 白叶枯病, 抗病性, 水稻, 突变体, 诱变育种