基于ITS序列分析豹子花属与5种百合的亲缘关系

Relationships among Species in Nomocharis and Lilium Based on ITS Sequences

以滇蜀豹子花和多斑豹子花为材料,采用PCR直接测序法测定其ITS序列,结合GenBank中其它3种豹子花和5种百合的ITS序列,构建了这10种植物的系统发育树。结果表明:(1)10种植物的ITS序列长度在625bp^627bp之间,总G+C含量在60.38%~61.12%之间,5.8S的G+C含量除大理百合为45.4%外,其余9种植物为55.01%或54.60%,说明ITS序列在进化上保守性较强,同属不同种甚至不同属间的长度差异不明显;(2)NJ、MP、ME聚类树的分支趋势一致,都是豹子花属植物先聚在一起再和5种百合相聚,滇西豹子花和豹子花在3种聚类树中都以99%以上的支持率聚成一支,说明这2个种的亲缘关系最近;(3)在10种植物中,形态相似且分布海拔和区域重叠的种类先相聚,说明这些物种的亲缘关系密切。

The sequences of ITS from Nomocharis forrestii and Nomocharis meleagrina were analyzed by PCR product direct sequencing. Using UPGMA（Unweighted pair group method with arithmetic mean）, NJ （Neighbor-Joining）,ME（Minimum evolution） and MP（Maximum parsimony） methods with MEGA2. 1 software,we built phylogenetic trees of the two Nomocharis and other eight species plants in GenBank. The results showed： （1）The sequence of ITS in 10 species ranged from 625 bp to 627 bp in length. The total G＋C content varied from 60. 38% to 61. 12%. The G＋C content of 5. 8S varied from 55. 01% to 54.60% except L. taliense. The results indicated that ITS sequences were very conservative,the lengths of ITS were close in different species of same genus or different genus. （2） The offset tendency of NJ, MP, ME trees was similar. Five species of Nomocharis first clustered together then grouped with five species of Lilium. N. farreri and N. pardanthina were clustered together with a bootstrap value 99% in 3 phylogenetic trees. （3）The species with similar morphological characters and from the same areas or neighboring geographical regions were first clustered together in the 10 kinds of plants,respectively. It suggested that they had higher genetic similarities and close relations.