利用RAPD标记水稻亲本遗传差异及其在杂种优势中的利用

Genetic Diversity Detected with RAPD Markers Among Rice Cultivars(Oryza sativa L.) and Its Utilizaton in Hybrid Rice Breeding

以１７个杂交水稻亲本、３个新株型株系和２４个光壳稻、爪哇稻品种为ＤＮＡ样品来源，通过随机引物ＰＣＲ扩增基因组ＤＮＡ的多态性，探索ＲＡＰＤ标记水稻亲本遗传差异在杂交稻育种中利用的可能性。研究结果表明，２２个１２碱基随机引物共扩增产物９８个，其中１７个引物可产生多态性产物，所扩增产物的４７．９％ 至少在两个基因型间存在差异。每个ＰＣＲ扩增产物分别以１和０记录存在与否。由ＲＡＰＤ数据计算的Ｎｅｉ＇ｓ遗传距离创建聚类树状图。聚类分析结果表明，籼稻和粳稻容易被分开，普通粳稻又容易与光壳稻、爪哇稻分开，但光壳稻和爪哇稻混合聚在一起。根据聚类图发现普通粳稻亚群内杂种优势较弱，亚群间即生态群间的杂种优势较强，群间即籼、粳亚种间杂种优势更强。利用光壳稻、爪哇稻选育不同生态群方向的恢复系和不育系，已配组育成超强优势的杂交稻组合。

Seventeen parents of hybrid rice and 3 new plant type lines and 24 Nuda,Javanica cultivars were used to evaluate genetic diversities by RPAD markers.It was explored that the possibility of genetic diversity estimated from RAPD banding patterns that could be used in hybrid rice breeding.Twenty-two 12-mer random primers were used for PCR reactions.The total of 98 distinguishable PCR products were detected by agarose gel electrophoresis among 44 parents,17 random primers were polymorphic and 47.9% of total products were different at least between two parents.Each of those amplified bands was taken as one variance which was record as 1 for present and 0 for absent.Based on the pair-wise comparsons of amplification products the genetic distance was calculated using Nei's genetic distance and a dendrogram was constructed using an unweighted pair group method with arithmetical averages (UPGMA).The indica and japonica cultivars were easily classified into separate groups by cluster analysis,and temperate and tropical japonica cultivars were classified into separate subgroups,too.But Nuda and javanica cultivars were usually clustered in mixed subgroup.The results from the dendrogram were found that the economical heterosis between temperate japonica cultivars was low,the heterosis between subgroups was stronger and the heterosis between groups (indica/japonica) was strongest.Making use of Nuda and javanica,parents of hybrid rice with distinct ecotype were bred,and super highyield hybrid rice combinations had been bred.