基于分子谱系地理学探讨白芷的栽培起源

Baizhi (Angelicae Dahuricae Radix) is a commonly used herbal medicine in China.Currently, the main four cultivated types("Qibaizhi","Yubaizhi","Hangbaizhi","Chuanbaizhi") have been recognized. Some have argued that all the four cultivar types were originated from Angelica dahurica var.formosana and were changed from one another during their long domestication history. The wild populations of A. dahurica var. formosana distributed in Zhejiang and Fujian provinces firstly became domestic Hangbaizhi, and then developed into Chuanbaizhi. Subsequently, Chuanbaizhi gradually evolved into Qibaizhi (Yubaizhi). However, these four cultivated types were only recognized as two cultivars in the flora of China: "Qibaizhi" and "Yubaizhi" are recognized as A. dahurica 'Qibaizhi', and "Hangbaizhi" and "Chuanbaizhi" are recognized as A. dahurica 'Hangbaizhi'. The taxonomic status of the original plant of these cultivated types as well as their domestic history is still in debate. Especially, the cultivated type “Hangbaizhi”, has long been cultivated in Zhejiang Province while its local natural distribution has never been reported. Was it A. dahurica var. formosana introduced from Taiwan? Or was it A. dahurica native to North China domesticated in Zhengjiang, and formed the variety A. dahurica var. formosana, which was subsequently naturalized in Fujian and Taiwan, but now survives only in Taiwan?. To answer the above questions, we are going to conduct a large-scale and multi-locus phylogeography study of four cultivated types of Baizhi, A. dahurica and A. dahurica var. formosana. The aim is to clarify the cultivation origin and domestication history of these cultivated types. This study would make important contributions to the germplasm innovation and sustainable utilization of Baizhi.

白芷是我国大宗常用药材，主要栽培类型有祁白芷、禹白芷、杭白芷、川白芷等。有研究认为，四者为相同种质，均来源于台湾当归（Angelica dahurica var. formosana），先由浙闽野生种群变家种成杭白芷，再发展到川白芷，又发展到祁（禹）白芷。但中国植物志认为，祁（禹）白芷和杭（川）白芷是白芷（A. dahurica）的两个栽培变种。各类白芷的基原植物分类地位和栽培起源到底如何？特别是在浙江一带长期栽培的杭白芷，至今在当地没有发现野生分布；其为从台湾引种到浙江而成？还是大陆的野生白芷在浙江引种驯化后变成台湾当归再分布到闽、台，而今野生种群仅孑遗于台湾？针对上述问题，本项目拟以白芷的四种栽培类型、白芷和台湾当归为研究对象，进行大尺度、多基因水平上（叶绿体DNA和核SSR标记）的亲缘地理学研究，以明确栽培白芷的物种和地理起源及驯化历史。本研究可为白芷的种质创新和可持续利用提供指导。

白芷是我国大宗常用药材，主要栽培类型有祁白芷、禹白芷、杭白芷、川白芷和亳白芷等。栽培白芷来源于台湾当归（Angelica dahurica var. formosana），还是来源于兴安白芷（Angelica dahurica）尚存较大争议。各类栽培白芷的基原植物分类地位和栽培起源及驯化历史到底如何？本研究以白芷的五种栽培类型、兴安白芷和台湾当归为研究对象，进行大尺度、多基因水平上（叶绿体DNA和EST-SSR标记）的亲缘地理学和群体遗传学研究。.研究结果如下： .1. 项目组完成了栽培白芷、兴安白芷、台湾当归的分布区资源考察工作(19个居群)，获得了大量宝贵的各类白芷分子材料和植物标本（544份，药材283份，植物标本75份）。.2. 通过基于叶绿体全基因组序列的系统发育重建，初步厘清了栽培白芷及兴安白芷和台湾当归的系统发育关系，栽培白芷与兴安白芷亲缘关系更为密切，推测兴安白芷更可能为栽培白芷的基原。同时，筛选出11对高变异cpDNA片段，可以用于系统发育研究及白芷及其易同属易混品的分子鉴定。.3. 基于二代测序技术（RNA-Seq）开发了12对具有高多态性和通用性的EST-SSR markers，用于栽培白芷、兴安白芷和台湾白芷的群体遗传学研究。通过对兴安白芷群体遗传学分析，为其保育提供了参考建议，如辽宁鞍山和吉林龙潭山居群遗传多样性高，可做种质来源，而北京和河北承德居群遗传多样性低，需要重点保护。通过对栽培白芷的群体遗传学分析，发现各类栽培白芷遗传多样性均较低，应该加强遗传多样性的保护，同时明确栽培白芷中优质品种为杭白芷（或川白芷），可以作为优质育种材料。栽培白芷的栽培路线为：杭、川白芷-祁禹白芷-亳白芷。本研究也筛选出1对诊断性引物（Locus AD7）可以准确鉴别白芷及紫花前胡。. 本研究为白芷的育种、品种改良及资源可持续利用提供科学依据，同时为白芷及其易混品的鉴别提供了新的cpDNA 和 EST-SSR markers。 项目共发表论文4篇，其中SCI收录3篇，中文核心期刊1篇。