转几丁质酶基因水稻抗纹枯病性及农艺性状遗传特性

目的]揭示转基因水稻的纹枯病抗性及其非目标变异性状的遗传特性,为合理利用转基因水稻进行抗病育种提供理论指导.方法]以海转A为父本、竹籼B为母本杂交,通过对杂交F1和F2代的抗病性状进行分析,揭示海转A的纹枯病抗性和部分非目标变异性状的遗传特性.结果]转基因海转A除抗纹枯病性较非转基因亲本竹籼B有显著提高外,还存在穗粒数和千粒重两个非目标性状的变异,穗粒数较竹籼B增加44.2%,而千粒重降低12.1%.海转A的抗纹枯病性表现为存在主效基因的多基因数量遗传特性,而穗粒数和千粒重表现为典型的数量性状遗传;此外转基因海转A的抗病性、穗粒数和千粒重3个性状的变异系数均显著大于竹籼B,说明其稳定性较低.结论]外源抗病基因的导入提高了水稻的抗病性,这种影响以主效基因的形式表达;而外源基因导入引起非目标性状的变异,但没有改变其原有的典型数量性状遗传特征.

Inheritance analysis on sheath blight resistance and agronomic traits of transgenic rice transformed with chitinsase-gene

Objective]The present experiment was conducted to study the inheritance of sheath blight resistance in transgenic rice and its crossing combinations and variations in some agronomic traits to reasonably apply transgenic rice in breeding of disease resistance.Method]Transgenic rice line Haizhuan A,transformed with chitinase-gene RC24,was used as male parent to cross with non-transgenic female parent Zhuxian B,and the sheath blight resistance was analyzed in their hybrid F1 and F2 offsprings to find out the inheritance characteristics of sheath blight resistance and variations in agronomic traits in Haizhuan A.Result]The results showed that,compared to female parent Zhuxian B,transgenic Huaizhuan A showed higher resistance to sheath blight and variations in agronomic traits in terms of 44.2% increase in grain number per panicle and 12.1% decrease in 1000-grain weight.The resistance to sheath blight in Huaizhuan A was due to polygenic quantitative heredity traits located on major genes,while its grain number per panicle and 1000-grain weight still belonged to typical quantitative heredity.Further,the coefficient of variation of resistance and two traits in Haizhuan A were higher than that of Zhuxian B,indicating that their stability decreased remarkably.Conclusion]It has been observed that some other resistance genes in transgenic rice enhanced its resistance,which was further influenced by transformed gene.Extra resistance gene may induce some variations in agronomic traits,but can not change the inheritance pattern of the traits.