Towards a resolved phylogeny for a new classification of Crocus L. (Irididaceae)

为番红花 (Crocus L.)（鸢尾科）的新分类解决系统发育问题

• 批准号: 327155231
• 负责人: Dr. Dörte Harpke
• 金额: --
• 依托单位: Arbeitsgruppe Experimentelle Taxonomie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/327155231?language=en
• 关键词: Towards; resolved; phylogeny; new; classification

The genus Crocus, comprising about 200 species, requires a taxonomic revision as several infrageneric and even intraspecific units were shown to be para- or polyphyletic and over 50 new species were described recently but, in most cases, not assigned to existing taxonomical groups. Moreover, as up to now phylogenetic investigations failed to produce a resolved phylogeny also the affiliation of several species and infrageneric groups is still unclear and it is not possible to establish a new classification. To obtain a resolved phylogeny, 25 chloroplast and nuclear markers will be sequenced using high-throughput technologies and analyzed with coalescent-based methods. Combined with our ongoing thorough morphological investigations we will be able to evaluate the most useful combination of morphological characters for (i) a new classification of the genus and to set the framework for the new monograph of the genus we are already working on. The obtained phylogeny will also be used to (ii) to clarify the geographical origin of the genus and its main lineages as well as getting insight into speciation/radiation processes by reconstructing the historical biogeography of the genus and divergence time estimations. In Crocus, it is evident by widely varying chromosome numbers (2n = 6 to 70) that dysploidy played an important role in differentiation processes. To (iii) get more insights on the impact of dysploidy on speciation process in Crocus genome sizes and chromosome numbers will be obtained and considered in a phylogenetic context. Generally, although common in angiosperms, dysploidy was studied in an evolutionary context only in few genera. Therefore, with Crocus an additional system could be studied to more generally infer the possible role of dysploidy in plant evolution. In addition to geographical isolation and reproductive isolation by dysploid chromosome numbers, speciation processes seem to be partly driven by hybridization in Crocus. Therefore, (iv) polyploid as well as homoploid hybridization events will also be inferred through the multi-locus analysis.

番红花属，包括约200种，需要一个分类学修订的几个亚属，甚至种内单位被证明是帕拉或多系，最近有超过50个新种被描述，但在大多数情况下，没有分配到现有的分类组。此外，由于到目前为止系统发育研究未能产生一个解决的亲缘关系，一些物种和属下组的隶属关系仍然不清楚，不可能建立一个新的分类。为了获得一个解决的遗传学，25个叶绿体和核标记将使用高通量技术进行测序，并与基于聚结的方法进行分析。结合我们正在进行的形态学研究，我们将能够评估最有用的形态特征组合，用于（i）属的新分类，并为我们正在研究的属的新专著建立框架。所获得的系统发育也将用于（ii）澄清属及其主要谱系的地理起源，以及深入了解物种形成，辐射过程的重建历史地理的属和发散时间估计。在番红花属中，染色体数目的广泛变化（2n = 6至70）表明异倍性在分化过程中发挥了重要作用。为了（iii）得到更多的见解，异倍性的影响，在番红花的物种形成过程中，基因组大小和染色体数目将获得和考虑在系统发育的背景下。一般来说，虽然在被子植物中很常见，但只有少数属在进化背景下进行了研究。因此，对于番红花，可以研究额外的系统以更普遍地推断异倍性在植物进化中的可能作用。除了异倍体染色体数目的地理隔离和生殖隔离，物种形成过程似乎部分是由杂交在番红花。因此，（iv）多倍体以及同倍体杂交事件也将通过多基因座分析来推断。