Recent research has discovered that an ancient homoploid interspecific hybridization event between ancestral species of the tomato lineage (Solanum sect. Lycopersicon) and sect. Etuberosum lineage in the nightshade family (Solanaceae) gave rise to the ancestral species of the potato lineage (sect. Petota) and generated the innovative "potato" tuber trait. This hybridization event not only introduced this key innovative trait but also triggered the exploitation of new ecological niches, ultimately leading to the explosive emergence of species within the potato clade. This study, together with related case studies in recent years, collectively reveals the universality of the molecular mechanism of homoploid hybrid speciation—namely, "generating innovative traits through the alternate inheritance of highly diverged alleles from both parental lineages". These findings hold significant implications for revising the traditional bifurcating speciation model and advancing the paradigm shift in artificial breeding practices.

Petota  /  Lycopersicon (tomato)  /  homoploid hybrid speciation  /  alternate inheritance  /  highly diverged alleles  /  innovative trait  /  universality