Does polyploidy facilitate long-distance dispersal?

Area of Science:

• Evolutionary biology
• Plant sciences
• Biogeography

Background:

• Plant lineage success is linked to global distribution, often achieved through long-distance dispersal (LDD).
• The attributes enabling successful LDD remain largely unknown.
• Polyploidy, common in invasive and Arctic flora, is a candidate trait for successful LDD due to wider ecological tolerances.

Purpose of the Study:

• To investigate the relationship between polyploidy and long-distance dispersal (LDD) in the grass subfamily Danthonioideae.
• To determine if polyploidy facilitates successful dispersal events in plant lineages.

Main Methods:

• Phylogenetic analysis of the Danthonioideae subfamily using a comprehensive species-level phylogeny.
• Inference of cytological evolution using maximum likelihood (ML) in ChromEvol.
• Reconstruction of biogeographical evolution using ML and Bayesian approaches.

Main Results:

• Numerous increases in ploidy levels were identified within the Danthonioideae.
• A polyploidy cycle during the Late Miocene-Pliocene coincided with LDD events.
• Polyploid lineages demonstrated a higher likelihood of successful LDD compared to diploid lineages.

Conclusions:

• Polyploidy appears to enhance the capacity for long-distance dispersal in plants.
• Frequent polyploidization in grasses may have been a key factor in their extensive intercontinental dispersal.
• Polyploidy likely contributed significantly to the evolutionary success and global distribution of the Poaceae family.