Progress seen in effort to save rare Taiwan plant from extinction

Taipei, April 14 (CNA) 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.

The endemic plant species, which was discovered in 1971, is only found within an area of less than 0.5 hectares around Menghuan Lake, Huang Yao-mou (黃曜謀), a researcher at the Taiwan Forestry Research Institute told CNA.

Although it grows in a humid subtropical climate zone, the species has faced threats from drought and competition from other species, which almost led to its extinction in 2006, Huang said.

In order to help save the species, Huang said, he conducted 3-to-5-years of observation, in which he noted that the plant released spores that passed the winter in the soil before germinating the following spring.

According to Huang, the cold winter temperatures play a role in activating the spores, with some germinating the following year and other taking up to 30 years.

Huang experimented by placing soil samples with Taiwan quillwort spores in a refrigerator at 4 degrees Celsius, removing some of the samples every two weeks.

He found that while the plant's megaspores normally took an average of 12 weeks to germinate, exposure to sustained cold temperatures could reduce that time to as little as two weeks.

Moreover, he found that 63 percent of the spores had germinated after 20 weeks stored at low temperatures, compared to only 26.5 percent in normal conditions.

More specimens also made it to later stages in the plant's life cycle, allowing them to be used for educational or research purposes and assisting in conservation efforts, Huang said.

Huang noted that Taiwan quillworts are the first plants in the genus Isoetes to have their genome sequenced, which is useful in studying the special type of photosynthesis, called CAM photosynthesis, used by them and some terrestrial plants.

As Isoetes in other neighboring countries, such as China, Japan and South Korea are almost all hybrids with Taiwan quillworts, the genome data also helps scientists better understand how Isoetes evolved, Huang said.

Huang and his team of researchers published the results of their study on the effects of cold treatment on Taiwan quillwort spore germination in the India Fern Journal last December.