日本扁柏部分双列杂交试验的RAPD遗传分析

RAPD作为一简易的DNA分子标记,在得以广泛应用的同时,存在着随机扩增的DNA条带并不遵行显性遗传模式,以及受PCR反应条件影响大等现象.以5个日本扁柏Chamaecyparis obtusa优树无性系及其部分双列杂交的12组合(各含30个体)F1代为材料,探讨RAPD标记的子代遗传及分离特征.研究结果表明:优树无性系中供试的46个引物中,14个引物扩增了42条多态的片段,筛选了其中7个引物扩增得来的14条片段进行分析,在子代中均能找到其对应的片段,且这些片段符合孟德尔的遗传分离规律.说明RAPD可作为遗传标记在日本扁柏中用于遗传分析.图1表2参18

Genetic analysis of RAPDs in Chamaecyparis obtusa using partial diallel test

To develop molecular markers for Chamaecyparis obtusa, the inheritance of RAPD fragments was studied in diploid tissues of 5 parents and 30 diploid controlled F_1 progenies in each partial diallel crosses of these parents. Of 46 primers tested, 18 primers yielded 135 reproducible fragments, of which 42 fragments (31%) were polymorphic among the parents.Fourteen fragments amplified from 7 primers were selected to test the segregation among controlled F_1 progenies. All fragments observed in the parents were found in the progeny. Segregation of all variable fragments observed in diploid materials fitted the proportions expected for a dominant Mendelian trait. The segregating fragments were either present or absent confirming the dominant character of RAPD variation. The usefulness of RAPD fragments as genetic markers for estimating genetic diversity was also discussed.