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

Screw tree (Helicteres isora)

Screw tree ( Helicteres isora ) is a species of plant in the Malvaceae family. It is a shrub or small tree, up to 8 meters tall. It has gray bark and alternate leaves, up to 22 cm long and 17 cm wide, oval in shape, with serrated edges and hairs. The flowers are red or white and reach a total length of 5.5 cm. The fruit is green when unripe, brown or gray when dry, twisted, spiral-shaped, and pointed at the tip. The seeds are black or brown, shiny, and diagonal, triangular, or rectangular. TAXON Kingdom: Plantae Phylum: Tracheophyta Subphylum: Angiospermae Class: Magnoliopsida Order: Malvales Family: Malvaceae Subfamily: Helicteroideae Tribe: Helictereae Genus: Helicteres Pluk. ex L. in Sp. Pl.: 963 (1753) Species: Helicteres isora L. in Sp. Pl.: 963 (1753) HETEROTYPIC SYNONYMS Helicteres baruensis var. ovata DC. in Prodr. 1: 476 (1824) Helicteres chrysocalyx Miq. ex Mast. in J.D.Hooker, Fl. Brit. India 1: 365 (1874) Helicteres corylifolia Buch.-Ham. ex Dillwyn in Rev. Hortus Malab....

Coromandel (Asystasia gangetica)

Coromandel ( Asystasia gangetica ) is a species of plants in Acanthaceae, perennials, vines and branching that are widely found on the edges of roads, shrubs and gardens, resistant to shade, used as fodder, especially cattle, goats and sheep, treatment, conservation of land and ornamental plants. A. gangetica has a height of 88-95 cm, rectangular-shaped stem, brownish green or purplish green, taproot and can emerge from branches. Petiole has a length of 0.5-6 cm. Ellipse-shaped leaves, unifoliate, green or dark green, arranged facing each other and do not have stipules. Leaves have a length of 8.5 cm, width 4.9 cm, area 69.42 cm3, length and width ratio is 1.8:1, heart-shaped base and taper front end, rough surface, flat edge, a main bone and 4 -6 lateral veins on each side. Coromandel produces flowers after 4 weeks to 2 months. Compound flowers, lined up on one side with a length of up to 25 cm. Flower stalks have a length of up to 3 mm. Trumpet type, white with a bottom stran...

East Indian globe thistle (Sphaeranthus indicus)

Gorakhmundi or gorakh mundi or mundi buti ka phool or mundi booti ka phool or sembung delan or East Indian globe thistle ( Sphaeranthus indicus ) is a species of plant in Asteroideae, a perennial, multi-branched, strong fragrance with erect stems, winged and toothed wings, growing wild in rice fields forming colonies, dense open rugs in the tropics. S. indicus has alternating sitting leaves, oval, narrow at the base, toothed and serrated, 1-3 cm long and green. Leaves 2-7 cm long, 1-3 wide, broad and deep wings, continuing into a large bone in the center of the leaf to a sharp tip and several lateral veins. The flower is round, grows at the tip, has a large and long stalk, is purple in color, 8-15 mm in size, consists of many tiny flowers, green or red or purple and has pale purple stamens. Head ovate-ellipsoid and 12-15 mm long. Phyllaries are white and have purple crest. Female flowers have a corolla tube 2-2.5 mm long. The bisexual flowers are 2.3-3 mm long and the hardened pa...