花瓣的多种起源是被子植物长期进化的结果，毛茛目因其特殊的分类地位及形态多样的花瓣，是研究花瓣起源不可替代的重要类群。花瓣在个体发育过程中呈现了丰富的系统演化信息，然而，由于花瓣形态发育特征不完整，花瓣特异基因很难解决花瓣的起源问题，导致该目花瓣起源及多样性的形态发育成因等问题仍然不清楚。本项目拟在课题组前期的工作基础上，以毛茛目6科36种植物为材料，从器官发生发育、组织分化、超微结构等发育解剖学的角度观察花瓣的动态变化，围绕花瓣的发育及多样性分化展开以下研究：（1）花瓣的形态发生发育；（2）花瓣的发育解剖学特征；（3）不育雄蕊（包括花瓣状、分泌性的不育雄蕊）的发生发育；（4）成熟花瓣和不育雄蕊的附属结构（蜜腺）的发育及细胞分化（超微结构）；（5）综合上述结果的祖先性状重建。基于以上内容阐明花瓣在毛茛目不同类群的发育特征，揭示该目花瓣的多样性形态发育成因，并依此探讨花瓣的起源问题。

Different origins of petal in angiosperm are the results of long-term evolution. Ranunculales is a remarkable group for its key taxon status, diversity of petals, and irreplaceable role in showing petal origin and evolution. Petals development present more systematic and evolution information, However, researches on petal development is rare, on the other hand, researches on petal identity gene could not reveal the origin of petal. Thus, the petal development, origin and morphological cause of diversity are still unclear. Based on our previous studies, 36 species of six families in Ranunculales will be investigated in this project, we focus on some dynamic changes of petal, such as ontogeny, tissue differentiation, ultra-structure, and other developmental anatomical characters, our goals are to: (1) examine petal morphogenesis and development feature; (2) investigate developmental anatomical features of petal; (3) study staminodes (petaloid, secretory) development; (4) compare nectary development and ultrastructure of petals with that of staminodes; (5) reconstruct ancestral trait. According to the results of above, we try to analysis petal development feature in different groups, to reveal the morphological cause of diversity of the petals in the group, and further more, to explore the true origin of petals in Ranunculales and basal eudicots.