DISSERTATION RESEARCH: Evolution and Development of Petals in Aizoaceae (Caryophyllales)

开花植物中花瓣的起源一直是植物学家们猜测和争论的话题。传统的理论认为，苞片(起源于叶状器官)和雄花瓣(起源于不育的雄性器官)具有多个独立的进化起源。最近，控制花瓣形成的高度保守的遗传程序的发现表明，所有花瓣状器官可能都受到类似的基因控制。这一假说将通过研究Aizoaceae中控制花瓣形成的遗传途径来验证。Aizoaceae是一组多汁植物，拥有两种非常不同类型的花瓣状结构，要么来自叶状器官，要么来自不育的雄性部分。花瓣是一项极其重要的进化创新，它无疑有助于开花植物在陆地生态系统中的成功定居。花瓣对农业也具有重要意义，因为许多作物依靠花瓣来吸引传粉者，以确保受精、结果和作物产量良好。这项研究结合正在进行的其他开花植物组的研究，将有助于了解花瓣是如何、为什么以及何时进化的。在阐明花瓣形成的遗传机制时，将有可能更好地理解这一进化创新的影响。此外，这些知识还可以用于农业品种的遗传改良。

The origin of the petal in flowering plants has long been a subject of speculation and controversy among botanists. Traditional theories suggest multiple independent evolutionary origins of bracteopetals (derived from leaf-like organs) and andropetals (derived from sterilized male organs). More recently, the discovery of deeply conserved genetic programs controlling petal formation suggests that all petal-like organs may be under similar genetic control. This hypothesis will be tested by examining the genetic pathways controlling the formation of petals in Aizoaceae: a group of succulent plants that possess two very different types of petal-like structures derived from either leaf-like organs or sterilized male parts. Petals are an extremely important evolutionary innovation that has undoubtedly contributed to the success of flowering plants in colonizing the terrestrial ecosystem. Petals are also of major significance for agriculture as many crops rely on petals to attract pollinators to ensure fertilization, fruit set and good crop yields. This study, in conjunction with ongoing studies in other groups of flowering plants, will help to understand how, why and when the petal evolved. In elucidating the genetic mechanisms underlying petal formation it will be possible to better appreciate the impact of this evolutionary innovation. Furthermore, this knowledge could be used to genetically improve agricultural cultivars.