Skip to main content

Gametophyte evolution, Hymenasplenium murakami-hatanakae Nakaike, the fifth family to produce independent gametophytes

NEWS - Nakaike spleenwort (Hymenasplenium murakami-hatanakae Nakaike) can survive for long periods without a spore-producing sporophyte. Researchers report that H. murakami-hatanakae undergoes alternation of generations as an independent gametophyte, the only one in the suborder Eupolypods II (Aspleniinae).

Gametophyte evolution, Hymenasplenium murakami-hatanakae Nakaike, the fifth family to produce independent gametophytes

Aspleniineae appear to have evolved independent gametophytes to adapt to rocky and isolated environments. The research opens the way to elucidating gametophyte evolution and other important questions in plant ecology. A diversity of fern species reproduce and fill environmental niches.

Noriaki Murakami of Tokyo Metropolitan University in Tokyo, along with a team from Showa University in Yamanashi, and the National Museum of Nature and Science in Ibaraki, collected specimens from Izu-Oshima Island in southeastern Japan, and used DNA analysis to trace the generations.

Aspleniineae is a suborder called Eupolypods II that includes 30 percent of the ferns on Earth and is a rare group. Studying this species further promises to reveal more about how ferns diversify and adapt.

Plants and algae have a complex cycle that they use to reproduce. Each species has two generations in the cycle, a sporophyte that has two sets of chromosomes (diploid) and a gametophyte that has one (haploid). When the gametophyte matures, it produces gametes to produce a diploid zygote.

The zygote continues to divide and eventually becomes a sporophyte. The sporophyte produces spores through a process that halves the number of chromosomes. These spores divide and develop into gametophytes, and the cycle continues.

Sporophytes and gametophytes generally depend on each other for nutrition, but ferns have a special place in biology because they are independent of each other, raising the intriguing possibility that they can live long periods without each other or live as independent gametophytes.

Murakami and his team collected H. murakami-hatanakae that live in dark, humid environments on rocks along warm-climate rivers in Japan and Taiwan. The team collected specimens on Izu-Oshima Island and used DNA techniques to identify the species. DNA extracted from chloroplasts to identify sporophytes and gametophytes was then compared. They found that the gametophytes of this species can survive for long periods in an environment completely isolated from the spores.

Original research

Yoneoka, K., Fujiwara, T., Kataoka, T. et al. Morphological and functional evolution of gametophytes in epilithic Hymenasplenium murakami-hatanakae (Aspleniaceae): The fifth family capable of producing the independent gametophytes. Journal of Plant Research (2024). DOI:10.1007/s10265-024-01553-0

Popular Posts

Redflower ragleaf (Crassocephalum crepidioides)

Sintrong or ebolo or thickhead or redflower ragleaf ( Crassocephalum crepidioides ) are plant species in Asteraceae, terma height 25-100 cm, white fibrous roots, generally grow wild on the roadside, yard gardens or abandoned lands at altitude 200- 2500 m. C. crepidioides has erect or horizontal stems along the soil surface, vascular, soft, non-woody, shallow grooves, green, rough surface and short white hair, aromatic fragrance when squeezed. Petiole is spread on stems, tubular and eared. Single leaf, spread out, green, 8-20 cm long, 3-6 cm wide, longitudinal or round inverted eggshell with a narrow base along the stalk. Pointed tip, flat-edged or curved to pinnate, jagged rough and pointed. The top leaves are smaller and often sit. Compound flowers grow throughout the year in humps that are arranged in terminal flat panicles and androgynous. Green cuffs with orange-brown to brick-red tips, cylindrical for 13-16 mm long and 5-6 mm wide. The crown is yellow with a brownish red...

Purwaceng (Pimpinella pruatjan)

Purwaceng or purwoceng or antanan gunung or Viagra of Java ( Pimpinella pruatjan or Pimpinella priatjan ) are small termas growing horizontally in Apiaceae, growing in villages on Dieng Plateau, Central Java Province, Indonesia, at 1,500 to 2,000 meters above sea level, the roots have medicinal properties for aphrodisiacs and are usually processed in powder form for a mixture of coffee or milk. P. pruatjan grows flat on the ground but does not propagate, small leaves are reddish green for 1-3 cm in diameter. This plant is only found in Java and grows in high mountain areas. A low population where industrial demand is very high results in increasingly scarce. Another place that is likely to become a purwaceng habitat is the Iyang Mountains and the Tengger Mountains in East Java Province. Efforts to multiply and cultivate have a big problem where these plants have difficulty producing seeds. In vitro propagation research through tissue cultivation has been carried out to overcome ...

Bitter vine (Mikania micrantha)

Sembung rambat or bitter vine ( Mikania micrantha ) is a plant species in Asteraceae, crawling or wrapped around trees, perennial that grows up to 27 mm per day in tropical climates, branched stems where heart-shaped or triangular leaves are arranged in pairs and a plant can cover more than 25 square meters in a few months. M. micrantha has square-shaped stems or longitudinal bones, light green, many branches and has fine hairs. The stems have segments for lengths of 75-215 mm, each segment has a pair of leaves, new shoots and flowers. New roots grow when the segments come in contact with the soil. The leaves are in pairs and facing each other. Strands do not have hair, heart-shaped or triangular with jagged edges, length 30-125 mm, width 15-60 mm. Petiole is 1-6 cm long and has fine hairs. The flower panicle grows from the armpit of the leaf and the tip of the stem, having 3-15 mm long stems. Each flower head has 4 minor flowers. The crown is greenish-white, tubular and measures ...