Impact of temperature on karyotype differences in Cynodon dactylon of different ploidy levels at different latitudes

Diploids were more susceptible to temperature fluctuations due to their highly asymmetrical karyotypes. Conversely, tetraploids were less affected by temperature variation, which was associated with their symmetrical karyotypes. The karyotypic symmetry of higher ploidy levels underpinned the greater stability of polyploids under temperature variation. Temperature changes along latitudinal gradients influenced karyotype changes in C. dactylon, and karyotype evolution was pivotal in polyploid formation. These findings provide a theoretical basis for understanding the ploidy evolution of C. dactylon, screening wild resources in response to climate changes, and breeding new varieties.