Are tetraploids more successful? Floral signals, reproductive success and floral isolation in mixed-ploidy populations of a terrestrial orchid

Abstract

The results suggest that floral isolation and increased reproductive success of polyploids may help to explain their successful persistence in mixed-ploidy populations. These factors might even initiate transformation of populations from pure diploid to pure tetraploid.

Coordinated Functional Divergence of Genes after Genome Duplication in Arabidopsis thaliana

“…A range of phenotypic and genotypic effects might explain the relative success of polyploids (Van de Peer et al, 2017). It has been observed that polyploidy can have a direct influence on the plant phenotype, leading, for instance, to bigger flowers and/or increased stature (Chen, 2010;Gross and Schiestl, 2015), as well as on the plant genotype, leading to genomic rearrangements and gene expression changes (Adams and Wendel, 2005;Chen, 2007;Buggs et al, 2011;Chester et al, 2012;Shi et al, 2015).…”

Autopolyploid lineage shows climatic niche expansion but not divergence inArabidopsis arenosa

“…In general, new species face two challenges: (1) they must evolve reproductive isolation to prevent gene flow with closely related species; and (2) they must establish a unique niche, either through ecological divergence or successfully outcompeting other species (Coyne and Orr, ; Via, ; Barton, ). Because crosses between plants of different ploidy levels frequently result in reduced hybrid fertility (Husband and Schemske, ; Husband and Sabara, ; Sweigart et al., ; Borges et al., ; Greiner and Oberprieler, ; Gross and Schiestl, ; Roccaforte et al., ; Pegoraro et al., ; however, see Lafon‐Placette et al., ), it has been suggested that polyploidization causes instantaneous speciation (Schluter, , ; Rundle and Nosil, ). However, for a new polyploid lineage to become a new species, it must also overcome the challenge of establishing a self‐sustaining population.…”

New records and range expansion for Paspalum procurrens and P. volcanense in northwestern Argentina and southeastern Bolivia

“…through niche differentiation; Karunarathne et al 2018). Ecological differentiation among cytotypes growing in sympatry or in zones of contact frequently involves a differentiation in flowering time, which reduces hybridization among cytotypes and thereby facilitates their coexistence (Thompson 1992;Gross and Schiestl 2015). These processes enhance speciation events and therefore contribute to increased local diversity.…”