YIA-PGR: Genetic, Molecular and Developmental Analysis of Variation in Tomato Fruit Morphology

通过对番茄的育种和突变分析，积累了丰富的种质资源，为番茄果实形态研究提供了丰富的资源。通常，果实的形态变化发生在授粉前子房的生长和成熟过程中，或授粉和成功受精后果实的成熟过程中。因此，显示果实形状改变的番茄品种可能为控制子房和果实生长和成熟的发育过程提供独特的见解。了解果实形态多样性的分子遗传学基础，将有助于深入了解番茄和其他果实作物的进化过程，以及调节子房和果实形成的发育过程的修改。第一个目标是鉴定和精细定位新的遗传位点，以获得控制番茄果实形状变异的关键位点和发育途径的全局视图。将对具有极端果实形状的栽培番茄与圆形果实野生近缘种杂交得到的群体进行表型和基因型分析，以确定控制果实形状的数量性状位点（QTL）。这些基因座将渗入到一个同质背景中，以允许未来的基因组分析和基于图谱的水果形态QTL基因克隆。第二个目标是确定番茄卵巢和果实生长过程中基因表达谱的变化，并将这些变化与形态学的发育变化联系起来。分析结果将为调控子房和果实发育的分子事件提供见解。此外，还将鉴定出由于果实形状位点的等位基因替换导致果实形态改变而导致转录水平改变的基因。这些信息将有助于深入了解水果形状基因座下游的基因网络和生化过程，以及水果形态如何受到调节。第三个目标是将项目过程中获得的水果形状特征与基因表达和基因型信息整合起来，并开发包含这些信息的可搜索数据库。此外，还将开发一个软件包，用于半自动分析番茄品种和种群的果实形状变化。

Breeding and mutation analysis in tomato have resulted in a diverse germplasm collection, providing a rich resource for studies on fruit morphology. Often, fruit morphological changes occur during growth and maturation of the ovary prior to pollination and/or during maturation of the fruit after pollination and successful fertilization. Therefore, tomato varieties displaying altered fruit shape may provide unique insights into developmental processes controlling ovary and fruit growth and maturation. Understanding the molecular-genetic basis of diversity in fruit form will allow insights into evolutionary processes in tomato as well as other fruit-bearing crops, and modification of developmental processes regulating ovary and fruit formation. The first goal is to identify and fine-map novel genetic loci to obtain a global view of key loci and developmental pathways controlling variation in tomato fruit shape. Populations derived from crosses between cultivated tomato exhibiting extreme fruit shapes and a round-fruited wild relative will be phenotypically and genotypically analyzed to identify quantitative trait loci (QTL) controlling fruit shape. These loci will be introgressed into a homogenous background to permit future genomic analyses and map-based cloning of genes underlying fruit morphology QTL. The second goal is to identify changes in gene expression profiles during tomato ovary and fruit growth, and to correlate these to developmental changes in morphology. Results from the analyses will provide insights into molecular events regulating ovary and fruit development. In addition, genes will be identified whose transcript levels change as a consequence of allelic substitution at fruit shape loci resulting in changes in fruit morphology. This information will allow insights into networks of genes and biochemical processes potentially downstream from fruit shape loci, and how fruit morphology is regulated. The third goal is to integrate fruit shape characteristics with gene expression and genotype information becoming available during the course of the project, and to develop a searchable database containing this information. In addition, a software package will be developed to semi-automatically analyze variation in fruit shape in tomato varieties and in mapping populations.