Research Paper

Development of sclerotic and winged seeds of Cyrtosia septentrionalis (Rchb. f.) Garay and Erythrorchis altissima (Blume) Blume (Orchidaceae)

Goro Nishimura, Koichi Kaburagi, Yung I Lee, Tomohisa Yukawa

Published on: 04 September 2023

Page: 359 - 367

DOI: 10.6165/tai.2023.68.359

Abstract

Although most orchid species produce minute, light seeds with a one-layer thin seed coat, some in the subfamily Vanilloideae show seed coat with sclerotization and wing development. We investigated the processes of their development by analyzing the anatomy of ovules of two species in the Vanilloideae, Cyrtosia septentrionalis (Rchb. f.) Garay and Erythrorchis altissima (Blume) Blume, that produce seeds with, respectively, rudimentary and well-developed wings. In both species, lignified dark material accumulated in the cells of the outermost layer of the outer integument, forming a sclerotic seed coat. Accumulation started from the cell walls of the outer periclinal surface. C. septentrionalis formed a large embryo and a rudimentary wing and E. altissima formed a small embryo and a well-developed wing. Fully developed seeds of C. septentrionalis and E. altissima were dispersed by animal and wing, respectively. In C. septentrionalis, vascular-bundle-like cells extended from the tip of the funiculus to the chalaza. In E. altissima, they branched into two parts: one reached the chalaza and the other reached a group of cells adjacent to the embryo sac in the micropylar region. The group of cells structurally and functionally resembled hypostase, although hypostase is reported to be present in the chalazal region. A helical vessel was found in one ovule in E. altissima. These observations indicate that the specialized cells represent degenerated vascular bundle cells.

Keyword: Anatomy, helical vessel, hypostase, Orchidaceae, sclerotic seed coat, vascular-bundle-like cells, winged seed

Literature Cited

Alomia, Y.A., Munoz, E.A., Acosta-Rangel, M., Otero, J.T. 2016 Morphometric analysis of Vanilla seeds (Orchidaceae) by microscopic techniques. Lankesteriana 16(1): 21–26.
DOI: 10.15517/lank.v16i1.23501View Article Google Scholar

Alves, M.F., Pinheiro, F., Niedzwiedzki, M.P., Mayer, J.L.S. 2019 First record of ategomic ovules in Orchidaceae offers new insights into mycoheterotrophic plants. Front. Plant Sci. 10: 1–11.
DOI: 10.3389/fpls.2019.01447View Article Google Scholar

Barthlott, W., Grosse-Veldmann, B., Korotkova, N. 2014 Orchid Seed Diversity. A scanning electron microscopy survey. Englera 32

Barthlott, W., Ziegler, B. 1981 Mikromorphologie der Samenschalen als systematisches Merkmal bei Orchideen Berichte der Deutschen Botanischen Gesellschaft 94: 267–273.

Beer, J.G. 1863 Beitr?ge zur Morphologie und Biologie der Familie der Orchideen. Carl Gerold’s Sohn, Vienna.
DOI: 10.5962/bhl.title.41518View Article

Cameron, K.M., Chase, M.W. 1998 Seed morphology of Vanilloid orchids (Vanilloideae: Orchidaceae). Lindleyana 13: 148–169.

Garay, L.A. 1960 On the origin of the Orchidaceae. Botanical Museum Leaflets, Harvard University 19(3):57–96.
DOI: 10.5962/p.295186View Article Google Scholar

Kimura, C. 1971 Embryological studies of Galeora septentrionalis Reichb. Fil. (Orchidaceae). Sci. Rep. Tohoku Imp. Univ., Ser. 4 Biol. 35:253–258.

Lee, Y.I, Yu, S.K., Liao, P.C., Wang, K.H., Lin, T.P. 2019. Newly discovered native orchids of Taiwan (XIV). Taiwania 64(4): 339–346.
DOI: 10.6165/tai.2019.64.339View Article Google Scholar

Maheshwari, F. 1950 An introduction to the embryology of Angiosperm. McGraw hill, New York.
DOI: 10.5962/bhl.title.5681View Article

Nishimura, G., Tamura, M. 1993 Seed coat formation in Apostasia nipponica. J. Jpn. Bot. 68: 219–223.

Nishimura, G., Yukawa, T. 2010 Dark material accumulation and sclerotization during seed coat formation in Vanilla planifolia Jacks. Ex Andrews (Orchidaceae). Bull. Natl. Mus. Nat. Sci., Ser. B. 36: 33–37.

Pansarin, E.R. 2016 Recent advances on evolution of pollination systems and reproductive biology of Vanilloideae (Orchidaceae). Lankesteriana 16(2): 255–267.
DOI: 10.15517/lank.v16i2.26010View Article Google Scholar

Rudall, P.J. 1997 The nucellus and chalaza in monocotyledons: Structure and systematic. Bot. Rev. 63(2): 140–181.
DOI: 10.1007/BF02935930View Article Google Scholar

Suetsugu, K. 2013 Autogamous fruit set in a mycoheterotrophic orchid Cyrtosia septentrionalis. Plant Syst. Evol. 299(3): 481–486.
DOI: 10.1007/s00606-012-0736-zView Article Google Scholar

Swamy, B.G. 1947 On the life history of Vanilla planifolia. Bot. Gaz. 108(3): 449–456.
DOI: 10.1086/335429View Article Google Scholar

Tilton, V.R. 1980 Hypostase development in Ornithogalum caudatum (Liliaceae) and notes on other types of modifications in the chalaza of angiosperm ovules. Can. J. Bot. 58(19): 2059–2066.
DOI: 10.1139/b80-238View Article Google Scholar

Withner, C.L., Nelson, P.K., Wejksnora, P.J. 1974 The anatomy of orchids. In Withner, C.L., The Orchids. Scientific Studies. Wiley. P. 271.

Yang, C.K., Lee, Y.I 2014 The seed development of a mycoheterotrophic orchid, Cyrtosia javanica Blume. Bot. Stud. 55: 44.
DOI: 10.1186/s40529-014-0044-8View Article Google Scholar