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

藏红花属包括约200种，需要对其分类进行修订，因为一些属内甚至种内单位被证明是准种或多种的，最近发现了50多个新种，但在大多数情况下，没有被分配到现有的分类类群。此外，由于到目前为止的系统发育研究未能产生一个确定的系统发育，而且一些种和非属群的隶属关系仍然不清楚，无法建立一个新的分类。为了获得一个确定的系统发育，将使用高通量技术对25个叶绿体和核标记进行测序，并使用基于聚结的方法进行分析。结合我们正在进行的彻底形态学调查，我们将能够评估最有用的形态学特征组合，以便(i)对该属进行新的分类，并为我们已经在研究的该属的新专著设置框架。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，以及通过重建属的历史生物地理学和分化时间估计来深入了解物种形成/辐射过程。在番红花中，染色体数目的广泛变化（2n = 6至70）表明，非倍体在分化过程中起着重要作用。为了（iii）在藏红花基因组大小和染色体数目的物种形成过程中获得更多关于倍体异常的影响的见解，并将在系统发育背景下进行考虑。一般来说，尽管在被子植物中很常见，但在进化背景下只在少数属中研究了倍体异常。因此，可以对藏红花进行额外的系统研究，从而更广泛地推断出异倍性在植物进化中的可能作用。除了地理隔离和生殖隔离，异倍体染色体数目，物种形成过程似乎部分是由杂交驱动的。因此，（iv）多倍体和同倍体杂交事件也将通过多位点分析推断出来。

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.