RAPD分子标记与小麦杂种优势相关性研究

Relationship between Heterosis and Genetic Distance Based on RAPD Marker in Hybrid Wheat

为了给杂种小麦亲本选配提供理论依据,利用RAPD标记技术对18个杂种小麦骨干亲本进行了遗传差异分析,并结合18个亲本所组配组合的杂种优势、超亲优势和特殊配合力测定,研究了RAPD遗传标记与杂种小麦亲本优势群划分和杂种优势预测之间的相关关系。结果表明,研究选用的RAPD标记在小麦中的多态性较低,筛选了80对引物,只有15对引物在18个亲本中多态性较高;基于这15对引物的扩增结果分析,所选用的RAPD标记能进行杂种小麦亲本优势群的划分,但RAPD遗传距离与杂种小麦产量构成因素之间存在不显著的正相关关系和负相关关系。在超亲优势水平,RAPD遗传距离与穗粒数呈极显著的负相关关系,RAPD遗传距离与亲本特殊配合力之间相关性不显著。笔者认为利用本文所选用的RAPD标记不能进行杂种小麦的杂种优势预测。

In order to study the heterosis of two parents in hybrid wheat breeding, the genetic distance of 18 core parents which were used in hybrid breeding practice was analyzed by Ramdom Amplified Polymorphism DNA （RAPD）, their heterosis over Mid-parent, high parent and special combining ability of 81 combinations which derived from the 18 core parents were tested in field. The results showed that the polymorphisms were low between core hybrid wheat parents. 15 primers of 80 were found to amplify polymorphic products. Based on polymorphic products of 15 primers, heterosis groups of hybrid wheat could be established. No significant positive correlation was found between RAPD genetic distance and yield heterosis of hybrid wheat. At the heterosis over high parent, the number of kernel on one head in hybrid wheat was lower than its male parents, even there was the biggest RAPD genetic distance between male and female parents. No significant positive correlation combining ability. It was considered that RAPD was found between RAPD genetic distance and special genetic distance might be difficult to predict heterosis of hybrid wheat.