The origin of polyploid genomes of bluegrasses Poa L. and Gene flow between northern pacific and sub-Antarctic Islands

A groundbreaking study reveals the complex evolutionary origins of polyploid bluegrass species (Poa L.) in New Zealand and its sub-Antarctic islands, highlighting significant gene flow between the Northern Pacific and these remote regions. Researchers used genetic sequencing of internal transcribed spacers (ITS1, ITS2) and 5.8S rDNA to demonstrate that highly polyploid species like P. cita, P. chathamica, and P. litorosa share a common ancestry with tetraploid species such as P. intrusa and P. anceps, forming a distinct clade. These findings challenge traditional taxonomic boundaries by showing strong genetic connections between New Zealand’s endemic bluegrasses and Arctic species like P. pseudabbreviata, while also identifying distant relationships with Eurasian diploid species. The study further uncovers the unique genetic divergence of Arctopoa species, which exhibit minimal variation (0.2%) among themselves but significant distances from other Poa sections. This research not only deepens our understanding of bluegrass evolution but also provides insights into the genetic exchanges shaping biodiversity across isolated island ecosystems.

Rodionov, A. V., Nosov, N. N., Kim, E. S., Machs, E. M., Punina, E. O., & Probatova, N. S. (2010). The origin of polyploid genomes of bluegrasses Poa L. and Gene flow between northern pacific and sub-Antarctic Islands. Russian Journal of Genetics, 46(12), 1407–1416. https://doi.org/10.1134/s1022795410120021