Plants show remarkable variation in the number of flowers they produce during their lifetime. This widespread variation traces back to differences in how, when, and where plants switch from making leaves to making flowers – the flowering transition. Although vitally important to crop yields, the transition to flowering, and the subsequent effects on shoot growth and flower production, remain poorly understood in many plants. For example, it is still not known why one species will form just a single flower each time there is a flowering transition, as in pepper, and yet another plant will grow dozens of branches bearing hundreds of flowers, as in some types of tomato. To address this fundamental question, this project is uniting a unique set of genetic, genomic, and natural variation tools in tomato and related Solanaceae plants, such as pepper, potato, and petunia, to reveal the genes and networks controlling flower production. By studying a collection of tomato mutants and wild Solanaceae species, this research will identify and characterize the differences in gene expression and DNA sequences that underlie variation in flowering transitions and flower production. This multi-dimensional project will identify key genetic regulators that drive the initiation and production of flowers in both agricultural and wild plants, which will enable the application of novel strategies to improve crop yields. The Solanaceae comprise the most valuable family for vegetable crop production, and we will deliver to both the public and scientific community broad genetic and genomic data in tomato, pepper, and edible wild Solanaceae species that have the potential to become agriculturally important crops.
Some of the most extensive variation in inflorescence complexity is found in the Solanaceae family. There are species possessing the simplest inflorescence of a single flower (e.g. gooseberry: Physalis peruviana), whereas others are highly branched and produce dozens of flowers (e.g. Chilean potato tree: S. crispum). In between are species with 2-3 flowers per inflorescence (e.g. passion berry plant: S. cleistogamum), tomato-like inflorescences (e.g. American black nightshade: S. americanum), and inflorescences with 2-3 branches (e.g. the wild tomato S. peruvianum).