Taipei: Researchers have learned to effectively propagate the Taiwan quillwort (Isoetes taiwanensis), a species of semi-aquatic herb that is only found near Menghuan Lake on Taipei's Yangmingshan, thus easing the immediate threat of extinction.
According to Focus Taiwan, the endemic plant species, which was discovered in 1971, is limited to an area of less than 0.5 hectares around Menghuan Lake, as stated by Huang Yao-mou, a researcher at the Taiwan Forestry Research Institute. The plant, although adapted to a humid subtropical climate, has faced threats from drought and competition from other species, nearly leading to its extinction in 2006.
To aid in the species' survival, Huang conducted a 3-to-5-year observation and discovered that the plant releases spores that endure the winter in the soil, germinating the following spring. Huang noted that cold winter temperatures are crucial for activating the spores, with germination periods ranging from one year to as long as 30 years.
Huang's experiments involved placing soil samples containing Taiwan quillwort spores in a refrigerator at 4 degrees Celsius and removing samples biweekly. His findings showed that while the plant's megaspores typically took about 12 weeks to germinate, exposure to sustained cold temperatures reduced this period to as little as two weeks. Furthermore, after 20 weeks stored at low temperatures, 63 percent of the spores germinated, compared to only 26.5 percent in normal conditions.
The increased germination and progression through the plant's life cycle have allowed more specimens to be used for educational and research purposes, aiding in conservation efforts. Additionally, Taiwan quillworts are the first plants in the genus Isoetes to have their genome sequenced, which has implications for studying CAM photosynthesis, a special type of photosynthesis they share with some terrestrial plants.
Huang also highlighted that in nearby countries such as China, Japan, and South Korea, Isoetes are almost all hybrids with Taiwan quillworts. The genome data thus contributes to a deeper understanding of how Isoetes evolved. Huang and his research team published their study results on the effects of cold treatment on Taiwan quillwort spore germination in the India Fern Journal last December.