“活化石”植物银杏形态与分子进化(Ⅰ)  

Relationship Between the Morphology and Molecular Evolution of “Living Fossil” Ginkgo biloba: Evidences from the Sequence Analyses of rDNA ITS

作　　者：陈月琴[1] 庄丽[1] 屈良鹄[1] 张宏达[1] 

机构地区：[1]中山大学生命科学学院

出　　处：《中山大学学报（自然科学版）》1999年第1期16-19,共4页Acta Scientiarum Naturalium Universitatis Sunyatseni

基　　金：国家杰出青年基金

摘　　要：测定了银杏雌株核糖体ｒＲＮＡ基因转录间隔区ｒＤＮＡＩＴＳ区全序列共１１７２碱基对，其中ＩＴＳ１长７８８碱基对，ＩＴＳ２２２６碱基对，５８ＳｒＲＮＡ基因１５８碱基对．采用计算机分析软件对所获得序列进行比较分析．结果表明：形态上仅有很少变化的银杏，其个体之间有明显的分子差异，不同产地栽培株ｒＤＮＡＩＴＳ区序列的核苷酸差异值高达２５％，这一差异远远大于一般意义上种间的距离，表明了该类植物形态上的变化与分子进化的不一致．造成形态与分子进化不一致的原因有待进一步探讨．A remarkable feature of Ginkgo biloba is that the species evolved so slowly that the morphological and anatomical structures of its fossils 200 million years ago and the present day representatives were almost identical The sequence of internal transcribed spacer (ITS) regions of nuclear ribosomal DNA (nrDNA) was determined for Ginkgo biloba to understand the link between molecular and morphological evolution The entire ITS and 5 8S regions of Ginkgo biloba (female strain) from a plantation in Guangzhou,China,are 1 172 bases long with an ITS1 of 788 bp,an ITS2 of 226 bp and a 5 8S of 158 bp The numerous copies of the ITS sequences within an individual showed a high level of sequence homogenity Sequence comparison using computer program showed that high sequence divergence between the strains we studied and that from Italy with the variation up to 25%,indicating that the low evolution rate of morphology in Ginkgo biloba does not reflect the rates of molecular evolution The relationship between the molecular characteristics and relic situation of this species needs to be further explored

关 键 词：银杏 形态演化 分子进化 Jie遗植物 

分 类 号：Q949.64[生物学—植物学]