伞形科鸭儿芹的种下变异以及系统进化研究

There are 5-8 species through the world.Cryptotaenia japonica Hassk.(Apiaceae）is one of the two intercontinental distribution species in North America and eastern Asia, which have analogous distribution pattern. It is the exceptional member of a small genus native to eastern Asia including China. Although, C. japonica Hassk. has been reported that it has reputed applied value, the others are lack of reported. It is a geographical ecoytpe with much morphological variations.The taxonomic case is unclear because of differences in taxonomic treatment between C. japonica Hassk.and its variations, which is the appropriate material to study intercontinental distribution and taxonomy and systematic evolution in Apiaceae. It is significant important between the evolution under species and the sustainable utilization of resources by gaining a clear idea of the problems. This object is the synthesized study, whose purpose is investigate the taxonomic problem, phylogenetic relationship, systematic evolution, etc., by the conclusive populations evidence of macroscopic and microscopic biological traits, palynology and ITS，trnH-psbA, LEAFY sequences. Combined with the data in modern geography and palaeogeography. The other objective of the study is to analyze the evolution trends of characteristical traits and geographic distribution and investigate the formation, development and change trends, and to study taxonomic case, compared with C. canadensis. It has theoretical significance and could be referenced to the study on the other Apiaceae.

鸭儿芹属Cryptotaenia DC.全世界有5-8种，鸭儿芹C. japonica是其中仅有的两个北美-东亚对应种、分布较广和具有相似的分布格局的种类之一，分布于东亚地区，但主产我国。不仅广泛应用于食用、药用、园艺等方面，更是从种类是否成立至种下分类等级都存有疑问，同时具有多样的地理生态分布类型和较大的形态变异，以及具有探讨洲际分布意义的价值，是探讨伞形科物种生物学和系统演化，种下进化与资源利用关系的理想种类。本项目拟在居群水平上，通过野外的调查分析、对各器官的宏观形态性状的统计分析、对繁殖器官的解剖学和孢粉学的微形态观察，以及ITS、trnH-psbA和LEAFY等DNA序列的差异分析，结合生境和地理信息，综合分析性状演化趋势及其在变异类型间的分布规律，以北美鸭儿芹为参照，解决该种是否成立以及种下分类问题，为鸭儿芹植物资源的利用和保护提供理论依据，为开展伞形科其他类似研究提供参考。

鸭儿芹属Cryptotaenia DC.全世界有5-8种，鸭儿芹C. japonica是其中仅有的两个北美-东亚对应种、分布较广和具有相似的分布格局的种类之一，分布于东亚地区，但主产我国。不仅广泛应用于食用、药用、园艺等方面，更是从种类是否成立至种下分类等级都存有疑问，同时具有多样的地理生态分布类型和较大的形态变异，以及具有探讨洲际分布意义的价值，是探讨伞形科物种生物学和系统演化，种下进化与资源利用关系的理想种类。. 通过研究，鸭儿芹叶片轮廓的分维值、矩形度、叶型系数、纵横轴比4个指标在居群内和居群间均具有丰富的变异，羽裂鸭儿芹与北美鸭儿芹在叶片形态上在叶片轮廓分维值方面，两者在一定程度上更为接近，而与深裂鸭儿芹和鸭儿芹原变型差别较大。矩形度与叶型系数呈线性相关，这与两者在供试材料中的分布规律吻合。分维值聚类分析表明，根据叶片边缘的锯齿、小叶柄有无情况（叶片自相似性程度）聚为高、中、低分维值3类，北美鸭儿芹与深裂鸭儿芹和羽裂鸭儿芹分维值较为接近，而与鸭儿芹原变型差距较大，提示北美鸭儿芹与深裂鸭儿芹和羽裂鸭儿芹具有更为接近的叶片形态。鸭儿芹各变异类型间的叶片轮廓分维值与经度、纬度呈负相关性。鸭儿芹各变异类型间的叶片矩形度、叶型系数与经度、纬度呈负相关性。鸭儿芹各变异类型间的叶片纵横轴比与经度呈负相关性，与海拔呈正相关性。. 对鸭儿芹进行简化基因组技术测序，每份种质资源平均获得原始3,881 ,709 reads 数条。得到8526656个Tag标签。 对Tag标签序列进行比对聚类，得到1293180个ddRAD标记，共检测到53222个SNP位点。基于SNP结果，对158个样品做遗传组分和结构分析，和进化分析，获得PCA点阵图，群体结构分析图和进化分析图。中国鸭儿芹分为2大进化枝，对分群分析表明，进一步可分为15个进化小枝。