Genomic analysis of 1,325 Camellia accessions sheds light on agronomic and metabolic traits for tea plant improvement

Abstract

The tea plant stands as a globally cherished nonalcoholic beverage crop, but the genetic underpinnings of important agronomic and metabolomic traits remain largely unexplored. Here we de novo deep resequenced 802 tea plants and their relative accessions globally. By integrating public Camellia accessions, we constructed a comprehensive genome-wide genetic variation map and annotated deleterious mutations for 1,325 accessions. Population genetic analyses provided insights into genetic divergence from its relatives, different evolutionary bottlenecks, interspecific introgression and conservation of wild relatives. Our findings suggest the pivotal role of southwest China as the origin of tea plants, revealing the genetic diversity and domestication status of ancient tea plants. Genome-wide association studies herein identified thousands of substantial associations with leaf shape and metabolite traits, pinpointing candidate genes for crucial agronomic and flavor traits. This study illuminates the tea plant's evolution and provides references for tea plant design breeding.