红豆杉脱分化过程中的遗传和表观遗传变异

采用扩增片段长度多态性（AFLP）和甲基化敏感扩增多态性（MSAP）技术分析红豆杉脱分化前后基因组DNA和DNA甲基化状态的变化。选用32个AFLP引物组合从红豆杉植株及其愈伤组织分别扩增出1834个片段，无多态性片段产生。这说明红豆杉植株在诱导形成愈伤组织的过程中基因组DNA保持高度的遗传稳定性。另用32个MSAP引物组合从红豆杉植株及其愈伤组织分别扩增出1197个片段，总扩增位点的甲基化水平由脱分化前的12．4％上升为16．2％，表明红豆杉在脱分化过程中的某些位点发生了甲基化。红豆杉脱分化前后的DNA甲基化模式也存在较大差异，说明DNA甲基化对愈伤组织形成有调控作用。

Genetic and Epigenetic Variations of Taxus media L. cv. Hicksii during Process of Dedifferentiation

The amplified fragment-length polymorphism （AFLP） and methylation-sensitive amplified polymorphism （MSAP） techniques were used to assess genetic and epigenetic variations of Taxus media during process of dedifferentiation. 1 834 bands were amplified from Taxus media plant and its callus with 32 pairs of AFLP primers, and no polymorphism fragments were detected. These indicated DNA genome of Taxus media kept highly genetic stability during the process of dedifferentiation. At the same time, 1 197 bands were amplified from Taxus media plant and its callus with 32 pairs of MSAP primers, methylation level rose from 12.4% to 16.2%,and epigenetic changes due to methylation were detected. What＇s more, methylation patterns experienced markedly variation, which meant DNA methylation would play role during the process of dedifferentiation.