菊花是由舌状花和管状花两种单花构成的头状花序，其舌状花丰富的形态变异是决定菊花花型多样性的关键。迄今对这种变异形成的机制尚不清楚。分子遗传学研究表明，花器官发育的同源异型基因、对称性和花瓣生长相关基因的差异表达均可使花朵形态发生变化。本课题组前期研究获得了一些舌状花形态变异突变体，初步分析发现了上述同源基因在不同突变体中差异表达的现象。据此本项目拟通过转录组数据分析，进一步分离上述同源基因及其家族成员；以保存的各种舌状花形态变异突变体为材料，利用基因表达分析和核酸组织原位杂交技术筛选控制舌状花形态变异的关键基因；继而构建关键基因的超表达和RNAi株系，通过分析不同株系表型验证关键基因功能，进而筛选关键基因的上游调控、水平互作和下游受控基因。在生物信息学分析的基础上探讨围绕关键基因的遗传调控网络。这一研究不仅可以解析菊花舌状花形态变异的遗传调控机制，亦可为人工调控菊花花型奠定理论基础。

The capitulum of chrysanthemum is composed of two types of single flower: ray floret and disc floret. The diversity of the capitulum form is determined by the variation of ray floret shape. Up to now, the regulatory mechanism of such variation is still not clear. It is proved that the variation of flower shape is relevant to floral homeotic genes, floral symmetry genes and petal growth regulation genes. We have found some ray floret shape mutants. The differential expression patterns of above-mentioned genes in different shape of ray florets were observed. Accordingly, we plan to clone the homologous genes by transcriptome analysis, then screening key gene in ray floret shape mutants using gene expression analysis and tissue specific RNA in situ hybridization. Then, verifying gene function in transgenic plants using overexpression and RNAi. Further, screening upstream genes, downstream genes and interacted genes on the basis of bioinformatics analysis, and infer the key gene-centric regulatory network. This study can reveal the genetic regulatory mechanism of ray floret variation in chrysanthemum and can also provide possibility for controlling of ray floret shape and then the capitulum form of chrysanthemum.