Comparative Genomics and Trait Evolution in Lettuce, its Wild Relatives and the Asteraceae

Summary

The Asteraceae family is the largest among flowering plants and comprises numerous members with economic and medicinal importance, such as lettuce (Lactuca sativa), a global crop. Lettuce breeding is facing significant challenges like pathogen invasion and environmental change. A practical and sustainable approach to address these challenges is to introduce novel genes/alleles from other species that display resistance or resilience.

To investigate genes of important traits for lettuce and Asteraceae, I utilized comparative genomics and analyzed de novo sequencing data from two wild lettuce species, Lactuca saligna and Lactuca virosa, as well as the close relative Taraxacum officinale (dandelion). The comparisons between Lactuca species provide breeding insights on various aspects, including chromosome compatibility, genome evolution, and immune gene variation, particularly for genes that encode receptor-like kinases (RLK) in response to lettuce downy mildew.

Furthermore, a broader comparison sheds light on the impact of the MADS-box and TCP gene families on flower development during the evolution of Asteraceae species.