Disjunct populations of Monocarpus sphaerocarpus (Monocarpaceae, Marchantiopsida) within Australia show no sequence variation

摘要

Populations of the complex thalloid liverwort Monocarpus sphaerocarpus D.J.Carr (Monocarpaceae) found in a disjunct distribution across southern Australia were sequenced to investigate whether plants found in eastern Australia were a different species from those found on the west coast of Australia, in line with potential differences in spore morphology. Sequences from five plastid gene regions were generated from specimens collected from several populations found in the states of Victoria, South Australia and Western Australia and spore morphology was reviewed using light and scanning electron microscopy. All individuals belonged to a single haplotype on the basis of the five plastid markers psbA-trnH, trnL-F, rbcL, rpoC1, and rps4-trnAS. Moreover, observed morphological differences were not consistent with geographical provenance and more likely indicative of infraspecific variation or difference in spore maturity when collected. These results support the recognition of only a single species in Australia.