Conclusions
Through extensive phylogenetic analysis using genetic variants from
transcriptomic data, combined with gene expression and functional traits
measured in common garden experiments, we tested the hypothesis
regarding differences in abiotic stress tolerance between octoploids and
tetraploids, as well as the functional stability of hybrid populations
in common reed. We conclude that octoploids are more tolerant to
high-salinity environments than tetraploids. Evidence suggests that
adaptive introgression has occurred, with adaptive genes being
transferred from the octoploid lineage to the tetraploid lineage.
However, the introgressed loci do not function stably in hybrid
populations, likely due to local adaptations within the divergent hybrid
populations or incompatible regulatory networks between the parental
genomes.