The origin of saffron. Part 2: The role of polyploidy for saffron secondary metabolites

番红花是番红花属植物中最重要的经济物种。它的长柱头被用来生产藏红花，这是世界上最昂贵的香料。在过去的三年里，我们能够弄清藏红花系列中的作物之间的关系，并能够识别出Cartwright tianus，有时也被称为‘野生藏红花’，是参与希腊南部藏红花形成和驯化的唯一祖先。藏红花是一种雄性不育的节段性异源三倍体，只能无性繁殖，这阻碍了所有的育种途径。既然藏红花的祖先和地理来源已经清楚，我们想要探索多倍体在作物形成中的作用，并筛选自然存在的卡特鲁蒂安和西红花的基因型和代谢物的多样性。从我们已经在阿提卡南部确定的芳香化学类型出发，我们将(I)探索倍性变化对代谢产物含量的影响，(Ii)比较不同倍性水平的个体之间的转录差异，(Iii)我们将着手进行初步的Cartwright tianus基因组草稿，以及(Iv)最后分析世界各地种植的大蒜品种的群体结构，以了解它们之间的关系和对不同气候条件的适应。随着这个项目第二阶段的工作，我们将为藏红花的预育种(或合成)计划以及更好地了解其宝贵特性的遗传基础打开可能性。

Crocus sativus is the economically most important species within Crocus. Its long stigmas are used to produce saffron, the worldwide most expensive spice. During the last three years we were able to clarify the relationships of the crop within series Crocus and could identify C. cartwrightianus, sometimes called ‘wild saffron,’ as the only progenitor involved in the formation and domestication of saffron in southern Greece. Saffron is a male-sterile segmental allotriploid that can only be propagated vegetatively, which prevents all breeding approaches. Now that the progenitor and geographic origin of saffron is clear we want to explore the role of polyploidy in the formation of the crop and screen the naturally occurring diversity of genotypes and metabolites of C. cartwrightianus and C. sativus. Starting from aromatic chemotypes, which we already identified in southern Attica, we will (i) explore the influence of ploidy change on the metabolite content and (ii) compare transcriptional differences between individuals at different ploidy levels, (iii) we will proceed with first steps towards a C. cartwrightianus draft genome, and (iv) finally analyze the population structure of the worldwide grown C. sativus cultivars to understand their relationships and adaptation to the different climate conditions they experience in their cultivation areas. With the work of this second project phase we will open up the possibility for a pre-breeding (or synthesis) program for saffron and for a better understanding of the genetic basis of its valuable properties.