摘要
选用 2 0个随机引物对 15个在生产和育种上广泛使用的中籼杂交稻亲本进行遗传多样性分析。 2 0个引物共扩增出 2 0 5条带纹 ,其中多态性带为 165条。不同引物的多态性频率有较大差异 ,但普遍较高 ,平均达 95 3 3 %。亲本间的遗传距离小 ,在0 12 10～ 0 3 913之间 ,平均 0 2 45 5。 15个亲本按UPGMA法可明显地分为不育系 (Ⅰ类 )和恢复系 (Ⅱ类 )两类 ,其中Ⅱ类又分为两个亚类 (Ⅱ 1和Ⅱ 2 )。类群内和类群间的遗传距离分析表明 ,不育系与恢复系内的遗传差异都较小 ,而且不育系的遗传变异较恢复系小 ;不育系和恢复系间的遗传距离只有 0 2 90 6,而且与恢复系两个亚类间遗传差异不显著 ,这说明杂交水稻亲本的遗传资源匮乏。亲本间的遗传差异小 ,这可能是限制当前杂交水稻产量的重要因素。增加亲本遗传多样性和扩大亲本间遗传差异是当前中籼杂交稻育种的重要任务之一。
semilate indica hybrid rice parental lines were analyzed by RAPD with 20 random primers The results showed that the 20 random primers produced 205 bands,of which 165 were polymorphic Frequencies of polymorphism were high with an average of 95 33 per cent and different with primers The genetic distances(GDs)between parental lines were small with a mean of 0 2455,ranged from 0 1210～0 3913 The GDs were then used to construct a dendrogram by unweighted pair group method with arithmetical averages(UPGMA) 15 parental materials were clearly classified into two groups,sterile line(group Ⅰ)and restoring line(group Ⅱ) The latter were classified into two subgroups,Ⅱ 1 and Ⅱ 2 The results of genetic distances among or between groups showed that the genetic differences were small in both sterile lines and restoring lines The GDs were smaller in sterile lines than in restoring lines The GDs was 0 2906 between sterile lines and restoring lines,and the genetic difference was not significant between sterile lines and two restoring line subgroups All this indicated that presently the genetic bases were narrow and genetic differences were small in semilate indica hybrid rice This was an important reason for the stagnant yield increase in hybrid rice Therefore,enriching the genetic diversity,expanding the genetic differences between parental lines was a key task in the present semilate indica hybrid rice breeding
出处
《西南农业学报》
CSCD
2002年第3期7-9,共3页
Southwest China Journal of Agricultural Sciences
