水稻细胞突变体HX-3无性系的变异

Somaclonal Variation in A Somaclonal Mutant HX-3( indica rice)

以水稻细胞突变体HX 3成熟胚为外植体 ,获得 5 88个R2 代体细胞无性系株系。观察其农艺性状和抗性 ,结果显示 ,HX 3的R2 代株系在株高、穗长、每穗总粒数、结实率、千粒重、抽穗期及抗病性等方面均发生变异。从R2 代株系中发现 3个农艺性状优良、抗白叶枯病且抽穗期较HX 3早 6～ 7d的株系 ,编号分别为HX 2 37、HX 2 70和HX 5 4 0。将这 3个材料分别与“龙特浦A”、“珍汕 97A”、“协青早A”和“Ⅱ 32A”配组 ,考察所配杂交组合的农艺性状。发现以龙特浦A配制的杂交组合均能正常抽穗结实 ,而其它 3个不育系配制的杂交组合在南京不能抽穗 ,说明这 3个材料仍有恢复性 ,但感光性没有发生变异。用国内外 2 1个白叶枯病菌株对这 3个突变体进行抗性鉴定 ,发现HX 2 37和HX 2 70与HX 3的抗谱相同 ,而HX 5 4 0对 3个菌株的反应与HX 3不同。并在HX 3的R2 株系中发现了一些感病株系 。

Five hundred and eighty eight somaclonal lines derived from mature embryo of somaclonal mutant HX 3 (indica rice) were analysed for their agronomic characters and resistance .It was showed that the disease resistance and some agronomic characters,including plant height,panicle length,spikelet/panicle, seed setting rate ,1 000 grain weight and heading date of R 2 lines varied as compared with HX 3.Among the R 2 lines ,three lines with good agronomic characters,resistance to bacterial blight of rice and 6～7 d shorter heading date than HX 3 were found.These three lines ( HX 237,HX 270 and HX 540) were crossed with 'Longtepu A' ,'Zhenshan 97A','XieqingzaoA' and 'Ⅱ 32A' F 1 hybrids from crosses between 3 somaclonal lines and Longtepu A obtained mature seeds,but crosses between the 3 lines and other 3 male sterile lines could not head,which showed that HX 237,HX 270 and HX 540 kept the restoring property and photo sensitivity of HX 3.The resistance of above three lines were tested by 21 bacterial blight strains collected at home and from abroad. HX 237 and HX 270 had the same resistance spectrum as HX 3, while HX 540 reacted to 3 bacterial blight strains used in the test differently from HX 3.It could also been speculated that reverse mutation should be responsible for the lose of resistance in some of the R 2 lines of HX 3