Format: ORAL

Alba Rodrguez Parra, Javier Lpez Jurado, Jess Picazo Aragons, Mario Fernndez Martnez, Claudia Moreno Portillo, Anass Terrab Benjelloun,Enrique Mateos Naranjo,Francisco Balao Robles.

Biología vegetal y Ecología, Universidad de Sevilla, Spain

Although polyploid species become successfully established in the short term, only a few persist in the long term. Interaction between polyploids with their ancestral cytotypes in secondary contact zones can contribute to these extinctions. Environmental factors as water availability and functional trait divergence may influence this competitive interaction.We conducted a greenhouse competition experiment with four cytotypes (2x, 4x, 6x, and 12x) of Dianthus broteri under two contrasting water regimes. We estimated niche and fitness differences and predicted the pairwise competitive outcomes. Additionally, we explored the influence of functional traits (SLA, AN, Fv/Fm, and iWUE) on competitive interactions. Water availability modified the competitive dynamics between cytotypes and predicted competitive exclusion. Under high water availability, cytotypes with lower ploidy levels (2x and specially 4x) exhibited the greatest competitive abilities while under low water availability, the higher level cytotypes (12x, 6x) overcompeted. These differences in competitive outcomes were explained by functional traits related to competitive effects (SLA) and competition tolerance (AN, Fv/Fm, and iWUE). Our study emphasizes that the long-term fate of polyploids largely depends on water availability, with polyploids having a competitive advantage in arid environments and highlighting the role of functional traits in shaping the competitive dynamics between cytotypes.