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

Porang (Amorphophallus muelleri)

Porang or iles-iles ( Amorphophallus muelleri ) is a plant species in Araceae, the petiole is a pseudo stem with a height of 40-180 cm, 1-5 cm in diameter, round, green or purple with irregular white spots, each branching point grows brown bulbil and yellow bulb. A. muelleri has all leaves or stems or stems that are light green to dark green or gray and has greenish-white patches, smooth or smooth surface. The leaves are elliptical in shape with pointed leaf tips, smooth and wavy surface. When flushing has 3, 4-5, 5-6 and finally 6 minor leaves branching with 3 minor petioles. Young leaves have light purple or green edges and will end in yellow and 0.3-0.5 mm wide. The whole canopy is 50-150 cm wide. The stems grow above the tubers with a diameter of 25-50 mm and a height of 75-175 cm. Tubers have a brownish yellow or gray color on the outer surface and brownish yellow on the inside, are slightly oval in shape, fibrous roots, weigh 450-3350 grams, smooth tissue, 4-5 months of dormanc...

Golden-armed mantis (Hierodula venosa)

Golden-armed mantis ( Hierodula venosa ) is an animal species in the Mantidae, winged praying mantis with females 65-75 mm long and males 45-65 mm, large but not the largest in the genus Hierodula and generally bright yellow with green and chocolate variations. H. venosa has a fully rotating head. The head is dominated by a pair of very large and brownish yellow eyes. The jaw forms a triangle. The back is very wide with thickened margins. A pair of long antennas. Wide wings with rounded tips, striped surface, thick margins, two small white plots on the right and left. The belly is large and jointed, curved downward, the upper part is completely covered by the wings, but partially visible from the side. The pair of forelegs are large and have three segments. The upper segment has rows of spikes on the front and back. The middle segment has a row of many spines on the back and a black tip. The third segment has a row of many spines, long, black and tipped with a long palm. The middle ...

Fern tree (Filicium decipiens)

Kerai payung or fern tree ( Filicium decipiens ) is a plant species in Sapindaceae, a tree that is always green with thick and round canopies such as umbrellas, 5-10 m high but old specimens in nature can exceed 25 m, upright stems, gray bark ash to reddish brown, smooth when young but rough and cracked when mature. F. decipiens has large, fern-like and conspicuous leaves, up to 40 cm long and made of elongated longitudinal, glossy green leaflets arranged in pairs. Leaves on stems with a length of 3-10 cm, alternating, imparipinnat, 15-30 cm long and 12-15 cm wide. Winged rachis with 6-12 pairs of opposite or sub-opposite leaflets, sessile, oblong-lanceolate with full margins and slightly wavy, 6-12 cm long and 1-3 cm wide, coriaceous, dark green and glossy above. Flowers grow on stems with a length of 7 cm as panicles for lengths of 15-30 cm which carry many small, unisexual flowers and hermaphrodites with a diameter of 0.4-0.6 cm. Pentaparted petals with imbricate ovate lobes, fi...