利用同工酶标记水稻亲本遗传差异及其在杂交水稻育种中的利用

Detecting Genetic Difference with Isozyme Markers among Rice Cultivars (Oryza sativa L.) and Its Utilization in Hybrid Rice Breeding

利用淀粉凝胶和聚丙烯酰胺凝胶电泳显示的同工酶差异 ,分析 17个杂交水稻亲本、3个新株型株系和2 2个光壳稻、爪哇稻品种的遗传差异 ,研究光壳稻和爪哇稻及其与温带粳稻之间的关系 ,探索同工酶标记水稻亲本遗传差异在杂交稻育种中利用的可能性。在本研究中 ,8个同工酶 18个多态性位点至少在 2个基因型间存在差异。每个具有多态性的酶谱带分别以 1和 0记录存在与否 ,由同工酶数据计算的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 ,普通粳稻与光壳稻、爪哇稻混合聚在一起 ;光壳稻与爪哇稻之间的遗传距离要比它们与普通粳稻之间的遗传距离小。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 ,已配组育成了强优势的杂交稻组合。

On the basis of the isozyme variation detected by starch and polyacrylamide gel electrophoresis,the genetic difference among the tested rice cultivars (O. sativa L.) including 17 parents of hybrid rice, 3 new plant type lines and 22 Nuda and javanica cultivars was analyzed to study the relation of temperate japonica to Nuda and javanica and to explore the possibility of utilizing the genetic difference detected with isozyme markers in hybrid rice breeding. The results showed that 18 polymorphic loci coding for 8 isozymes were surveyed and they were different at least between two genotypes. Each of those polymorphic isozyme bands was scored 1 for present and 0 for absent. Based on the pair wise comparisons of isozyme bands 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 major groups by cluster analysis, but temperate japonica and Nuda and javanica cultivars were clustered into the same mixed major group. The genetic distance between javanica and Nuda was smaller than that between them (javanica and Nuda) and temperate japonica. By way of breeding the parents of distinct ecotypes with Nuda and javanica cultivars as the breeding materials, the hybrid combinations with strong heterosis have been developed.