Evidence for interspecific hybridization in bryophytes during pre-molecular and molecular eras

Interspecific hybridization had been long recognized as a widespread evolutionary process in vascular plants. In the present review, we summarize knowledge concerning studies of interspecific hybridization in bryophytes before and after the advent of molecular methods. The available data indicate that hybridization is an important evolutionary phenomenon among bryophytes. Evidence for hybridization events before the molecular era is mainly based on studies of intermediacy of parental morphology. The recent molecular marker technology has revolutionized studies of hybridization, generating new insights into the genetic and evolutionary consequences of homoploid and allopolyploid speciation. The current molecular approaches support the prevalence of allopolyploidy in bryophytes. However, we anticipate that homoploid hybridization is under-reported. Finally, we suggest some directions for future studies of hybrid speciation among bryophytes.