【摘要】 本文在前期苗叶瘟抗谱测定的基础上,通过对空间诱变粤香占和青华占高代品系(6代以上)病圃田间穗颈瘟的鉴定,表明苗期表现抗稻瘟病的品种多数在成熟期同样表现抗或高抗稻瘟病。SSR多态性分析表明粤香占和青华占突变品系与原种间存在1.6%～17.4%和7.2%～10.4%的多态性频率,并存在3种多态性表现形式:(1)扩增片段数增加,(2)扩增片段数减少,(3)扩增片段大小有差异。说明由空间环境诱导的DNA变异可能并非是单纯的点突变。进一步分析诱变品系的多态性频率与抗病性的关系,发现部分诱变品系的抗性随着多态性频率的增加而提高。更多还原

【Abstract】 On the basis of former testing on leaf resistance,some high generation(6th and up)mutant lines from the seed of Yuexiangzhan and Qinghuazhan carried by high space balloon and showed a broad spectrum of resistance to the blast isolates were selected and detected for neck resistance.The results demonstrated that the lines were showing neck blast resistance as well as in the blast zone nursery in the field.SSR analysis showed that the polymorphism frequencies between Yuexiangzhan,Qinghuazhan and their mutant lines were 1.6%-17.4% and 7.2%-10.4%,respectively.Their SSR polymorphism patterns were as follow:(1)more amplification fragments,(2)less amplification fragments,(3)length difference of amplification fragments,whose ratio was the largest when compared with the two original varieties.The results showed that the DNA variation induced by space environment might not be simple location mutation.Compare of polymorphism frequency and the resistance in mutant lines showed that the resistance was increased as the SSR polymorphism frequency increased in part of mutant lines.更多还原