蔷薇目共有9科261属约7725种，广布于全球的热带到寒带的多种生境，是基于系统发育树研究地理格局形成和物种多样化的理想类群。但蔷薇目很多分支，尤其是末端分支的系统发育关系尚未解析，基于系统发育树的分布格局形成和物种多样化的研究更为少见。与植物分子系统和进化领域的著名植物学家Douglas E. Soltis等人合作，创新二代测序方法，获得植物三个基因组的数百个基因片段，重建该目约68%（5249种）物种的高分辨率和高支持率的生命之树。用最新方法整合形态、功能性状、分布、固氮性状、化石等数据，深入探讨蔷薇目如何实现全球分布，如何实现物种多样化，如何形成根瘤共生固氮等科学问题。本项目实施将帮助我们深入理解蔷薇目物种多样化和根瘤固氮，产出系列有世界影响的研究成果，联合培养若干优秀科研骨干和研究生，进一步提升我国在植物分子系统学和进化生物学领域的研究水平和原始创新能力。

Rosales contain 9 families, 261 genera and ca. 7725 species, which are globally distributed in many habitats from tropical to frigid zones. Rosales supply an excellent group for studying the formation of geographical pattern and species diversification. However, many phylogenetic relationships, especially those of the shallow branches, are not resolved. There are only a few studies on the formation of distribution pattern and species diversification. We will collaborate with researchers at the Florida Museum of Natural History (Douglas E. Soltis, Pamela S. Soltis, Robert P. Guralnick, Ryan Folk), the world’s leading botanists in plant molecular phylogenetics, evolution, and biodiversity informatics, to carry out this project. This project will apply improved NGS methods to sequence hundreds of nuclear, plastid and mitochondrial gene loci, and reconstruct a highly resolved and supported tree of Rosales with high sampling coverage (68% total species/5249 species). Integrating morphological traits, functional traits, distribution data, nodulation status, fossils, and genomic data, a series of scientific issues will be addressed: How did Rosales disperse into nearly all ecosystems? How did Rosales diversify, and did that diversification relate to acquisition of key traits or the ability to colonize new areas? Could genome size evolution/ancient polyploidy have promoted diversification in Rosales? Which among these factors, if any, were associated with the gain of N2-fixing symbioses? Interdisciplinary integration of different data layers puts this collaborative project on the frontier of plant phylogenetics, evolution, and ecology. This project will provide a solid basis for further study of Rosales evolution and diversification, produce a series of international influenced research results, result in the joint supervision on a number of excellent graduate students, and promote a high research level and initial innovation capability in plant molecular phylogenetics and evolution in China.