Ontogenetic characterization of sporangium and spore of Huperzia serrata: an anti-aging disease fern

Abstract

Background Huperzia serrata is a medicinal plant used in Traditional Chinese Medicine, which has been used to prevent against aging diseases. It is mainly propagated by spores and grows extremely slowly. Due to severe harvest, it is a highly endangered species. In this report, we characterize ontogenesis of sporangia and spores that are associated with propagation. A wild population of H. serrata plants is localized in western Hunan province, China and protected by Chinese Government to study its development (e.g. sporangia and spores) and ecology. Both field and microscopic observations were conducted for a few of years.ResultsThe development of sporangia from their initiation to maturation took nearly 1 year. Microscopic observations showed that the sporangial walls were developed from epidermal cells via initiation, cell division, and maturation. The structure of the mature sporangial wall is composed of one layer of epidermis, two middle layers of cells, and one layer of tapetum. Therefore, the sporangium is the eusporangium type. Spore development is characterized into six stages, initiation from epidermal cell and formation of sporogenous cells, primary sporogenous cell, secondary sporogenous cell, spore mother cell, tetrad, and maturation.ConclusionThe sporangial development of H. serrata belongs to the eusporangium type. The development takes approximately 1 year period from the initiation to the maturation. These data are useful for improving propagation of this medicinal plant in the future.

Documenting the Sporangium Development of the Polypodiales Fern Pteris multifida

“…The general cell divisions in this study are consistent with the previous reports (Wilson, 1958b(Wilson, , 1999Brown and Lemmon, 1980;Rincón Barón et al, 2011;Long et al, 2016). However, the cell wall of the tapetum and the spore mother cell degraded during meiosis, which makes the actual behavior of these layers difficult to recognize in the sections of the previous investigation (Wilson, 1958b).…”

“…Fern plant shows great differences in sporangium morphology. Sporangium development in leptosporangiate had been carried out since Sheffield and Bell, 1979; the later decades of the 19th century (Bower, 1891;Wilson, 1958bWilson, , 1999Long et al, 2016). Based on the research in some common genera, such as Plagiogyria, Asplenium, Pteridium, Pyrrosia, Xiphopteris of Polypodiales, fern sporangium development has been established (Bower, 1910;Warren and Wager, 1953;Wilson, 1958bWilson, , 1960Holttum et al, 1970;Sheffield and Bell, 1979).…”