| Abstrakt: |
ABSTRACTThe genus Kumanoais the most species-rich group in freshwater red algae. Only one species, K. mahlacensis, has been reported in Taiwan. Here, we described two new species, K. taiwanensisand K. yuanyangensis. Based on rbcL and cox1, K. taiwanensisdiffers from its sister lineage (K. curvataand K. intorta, both endemic to China) by 3.7%–3.9% and 6.6%, while K. yuanyangensisdiffers from its sister species, K. vittata(endemic to Australia), by 2.9% and 8.2%. These genetic differences exceed the threshold of species boundary in Kumanoa, supporting their establishment as new species. The two new species proposed are also supported by three algorithmic species delimitation methods (i.e. ABGD, SPN and GMYC). In addition to molecular evidence, K. taiwanensiscan be morphologically distinguished from K. intortaand K. curvataby having carposporophytes embedded in the whorl radius, monosporangia on the fascicles but not on the involucral filaments, and the lack of bisporangia. Kumanoa yuanyangensiscan be morphologically differentiated from K. vittataby having barrel-shaped whorls and spermatangia on the regular fascicles but not on the short, specialized fascicles. Comparing the three Taiwanese species, K. mahlacensisand K. taiwanensisare dark green or blue green in colour and occur in warm alkaline environments, reflecting their close phylogenetic affinity. In constrast, Kumanoa yuanyangensisis dark red-brown in colour, lacks monosporangia and occurs in a cold and acidic environment. This study expands the known diversity of Kumonoaand sheds light onto their biogeography. |
