‘石硖’龙眼大果型桂花味芽变系的RAPD分析鉴定

Identification of Large Fruit and Sweet Osmanthus Flavour Sport from 'Shixia'Longan Using RAPD Marker

用160个10 bp单个和混和随机引物对‘石硖’龙眼大果型桂花味芽变母树芽变枝及普通枝的基因组DNA进行RAPD扩增分析,从中筛选出6个单引物(S71、S161、S303、S304、S341、S1212)和4个双引物(Z7、Z59、Z60、Z70)能在二者之间扩增出稳定的多态性片段。10个引物共扩增出99条片段,其中多态性片段有S71-560、S161-813、Z70-800等13条,占13.1%,表明芽变枝果实大小及风味的变化与其遗传物质的改变密切相关。用两个特异引物S71、Z70对来源于同一芽变枝不同树龄的芽变嫁接单株及对照进行RAPD扩增,所得特异片段与引物筛选中完全一致,进一步表明芽变引起的遗传物质的改变可以通过无性繁殖的方式稳定存在,利用特异引物可对芽变嫁接单株的结果性状做早期预测。

Genetic DNAs from ‘Shixia＇ longan （Dimocarpus longana Lour. ） and its sport line which could generate larger fruits containing sweet osmanthus flavour were amplified by RAPD with 160 10 bp single and mixed random primers to study the genetic substance change of the sport. Six single and four mixed primers were screened which could produce stable polymorphic segments between the two clones. 13 out of the total 99 fragments amplified were distinctive including the loss of a normal segment and appearance of a new one. The polymorphic fragments amplified were S71-560, S161-813, Z70-800, etc. The difference of amplified DNA segments showed that the large fruit and sweet osmanthus mutant was closely related to changes of some genetic substances in the sport line. Further studying also showed that the genotype of the sport could be inherited stablely by way acters of the grafted of asexual propagation. The polymorphic segments could be used to forecast the fruit charseedlings from the sport scion.