Do floral and niche shifts favour the establishment of new polyploids?

Polyploidization plays a critical role in plant evolution. The majority of neopolyploids do not become established, either because they have fewer potential mates, or may not be able to successfully compete with co-occurring progenitors at lower ploidy levels. Casazza et al. assess floral traits and ecological preferences that might be involved in establishment and persistence for polyploids of Primula marginata and Primula allionii and their hexaploid progenitors.

Floral traits measured in individuals of P. marginata (hexaploids and dodecaploids) and P. allionii (hexaploid species).
Floral traits measured in individuals of P. marginata (hexaploids and dodecaploids) and P. allionii (hexaploid species). Diagrams of long-styled (L) and short-styled (S) morphs. Sexual organ traits: AP, anther position; SP, stigma position. Corolla traits: TL, corolla tube length; MD, corolla mouth diameter; LL, petal limb length.

The results might explain the origin of polyploidized populations, suggesting that dodecaploids established and persisted by occupying geographical areas not yet filled by their closest relatives yet without significant evolution in their climatic and pollination niches.

Reference List

Casazza, G., Boucher, F. C., Minuto, L., Randin, C. F., & Conti, E. (2016). Do floral and niche shifts favour the establishment and persistence of newly arisen polyploids? A case study in an Alpine primrose. Annals of Botany, 119(1), 81–93. https://doi.org/10.1093/aob/mcw221