分子标记技术在白木香遗传变异研究中的应用

采用简单重复序列区间扩增(ISSR)技术和核糖体RNA基因(rDNA)转录间隔区(ITS)序列分析技术, 对不同地区白木香的遗传变异、亲缘关系及分子鉴定进行研究. 共筛选出7条ISSR引物, 扩增得到80条带, 其中多态性条带的比率是58.8％. 白木香9个居群之间的遗传距离是0.0733～0.4213, 居群间遗传差异不大; 筛选出的引物IS-8可以进行白木香种内和种间的鉴别. ITS序列在白木香种内的变异很小, 只有6个变异位点, 种内遗传距离为0.0％～1.1％. 根据白木香ITS的序列特征可准确鉴别白木香与近缘种. 两种分子标记方法得到的UPGMA聚类图不一致, 但大致趋势相同, 说明ISSR标记与ITS序列分析均可用于白木香遗传变异及亲缘关系的研究, 但ITS序列分析技术在种内遗传变异研究的分辨力不及ISSR高.

The Application of Molecular Marking Technology on Genetic Variation of Aquilaria sinensis

Inter simple sequence repeat (ISSR) markers and the DNA sequences of ribosomal DNA internal transcribed spacer (ITS) were used to analyze the genetic variation, relationship and molecular authentication of different populations of Aquilaria sinensis. A total of 80 bands were amplified with 7 ISSR primers, and the percentage of polymorphic bands was 58.8％. The genetic distance was from 0.0733 to 0.4213 and the intraspecific genetic variation was low. Primer IS-8 could be used to authenticate the populations of A.sinensis and their adulterants. The variation of rDNA ITS sequence was not significant and only 6 variable sites were found among populations. The difference of ITS sequences can be used to authenticate accurately A.sinensis from their adulterants. The molecular cluster obtained from two methods were different but the trend was similar, which indicated the two methods were used to revealing genetic variation in A.sinensis, but ISSR could detect more intraspecific genetic variation than ITS sequences.