Pollinia Development in a New Species of Pennilabium yunnanense(Orchidaceae)

doi:10.7525/j.issn.1673-5102.2020.02.001

Abstract

Abstract: Pennilabium J. J.Sm. is a newly recorded genus in China, including two species founded in Yunnan and Hainan. One of them is a new species of P.yunnanense. In this paper, floral morphology and pollina development in P.yunnanense were investigated. The column of a mature flower is short without column foot. Pollinarium unit is composed of two subglobose pollinia, stipe and viscidium. In the early stage, anther primordium is differentiated into a pair of lateral juxtaposed thecae. At the stage of microsporocyte, an incomplete sterile septum is formed adjacent to the inner anther wall between two thecae. During the microsporogenesis, the sterile septum becomes gradually degraded, resulting two pollinia with pore toward the inner anther wall disorganized. The hypodermal sporogenous cells produce 4-layered anther wall by periclinal divisions, including epidermis, endtothecium, middle layer, and a tapetum, which was of monocotyledonous type. Tapetum is uninuclear and secretory. Epidermis is not persistent, which becomes degraded as well as middle layer and tapetum. Fibrous thickenings occur on the entdothecium. Simultaneous cytokinesis results in tetrahedral and isobilateral microspore tetrads. Microspores undergo a mitosis leading to 2-celled pollen tetrads. Pollen tetrads arranged tightly and formed a subglobose pollinium in each theca. The embryological data on pollinia development of P.yunnanense could provide new insight for a better understanding of biodiversity and conservation in Orchidaceae.

Key words: microsporogenesis, male gametogenesis, Orchidaceae, pollinia development, Pennilabium yunnanense

CLC Number:

Q949.71+8.43

LI Lu, ZHANG Jin, LI Chu-Ran, WANG Yan-Ping, TAN Qing-Qin, LUO Yan. Pollinia Development in a New Species of Pennilabium yunnanense(Orchidaceae)[J]. Bulletin of Botanical Research, 2020, 40(2): 161-171.

References

[1] Brown R.Prodromus florae Novae Hollandiae et Insulae Van Diemen[M].London:R.Taylor et Socii,1810.
[2] Lindley J.Orchidearum sceletos[M].London:Richard Taylor,1826.
[3] Cameron K M,Chase M W,Whitten W M,et al.A phylogenetic analysis of the Orchidaceae:evidence from rbcL nucleotide sequences[J].American Journal of Botany,1999,86(2):208-224.
[4] Singer R B,Gravendeel B,Cross H,et al.The use of orchid pollinia or pollinaria for taxonomic identification[J].Selbyana,2008,29(1):6-19.
[5] Johnson S D,Edwards T J.The structure and function of orchid pollinaria[J].Plant Systematics and Evolution,2000,222(1-4):243-269.
[6] Freudenstein J V,Harris E M,Rasmussen F N.The evolution of anther morphology in orchids:Incumbent anthers,superposed pollinia,and the Vandoid complex[J].American Journal of Botany,2002,89(11):1747-1755.
[7] Chen S C,Luo Y B.Pennilabium yunnanense,a new species of Orchidaceae from Yunnan,China[J].Acta Phytotaxonomica Sinica,2004,42(5):457-459.
[8] Chen X Q,Liu Z J,Zhu G H,et al.Orchidaceae[M].Wu Z G,Raven P H,Hong D Y.Flora of China.Beijing:Science Press; St.Louis:Missouri Botanical Garden Press,2009,25:1-506.
[9] The Plant List.Version 1.1,[EB/OL].(2013-01-01)[2019-03-10].http://www.theplantlist.org
[10] Schuiteman A.A very odd little thing:Pennilabium hewittii(Orchidaceae)[J].Kew Bulletin,2013,68(4):679-681.
[11] Huang M Z,Wang Q L,Liu Z L,et al.A new record of Pennilabium(Orchidaceae),P.struthio Carr from China[J].Guihaia,2014,34(5):670-672.
[12] Averyanov L V,Nguyen V C,Truong B V,et al.New Orchids(Orchidaceae:Cymbidieae and Vandeae) in the Flora of Vietnam[J].Taiwania,2018,63(2):119-138.
[13] Hidayat T,Yukawa T,Ito M.Molecular phylogenetics of subtribe Aeridinae(Orchidaceae):Insights from plastid matK and nuclear ribosomal ITS sequences[J].Journal of Plant Research,2005,118(4):271-284.
[14] Zou L H,Huang J X,Zhang G Q,et al.A molecular phylogeny of Aeridinae(Orchidaceae:Epidendroideae) inferred from multiple nuclear and chloroplast regions[J].Molecular Phylogenetics and Evolution,2015,85(2):247-254.
[15] Hidayat T,Weston P H,Yukawa T,et al.Phylogeny of subtribe Aeridinae(Orchidaceae) inferred from DNA sequences data:Advanced analyses including Australasian genera[J].Jurnal Teknologi,2012,59(1):87-95.
[16] Chase M W,Cameron K M,Freudenstein J V,et al.An updated classification of Orchidaceae[J].Botanical Journal of the Linnean Society,2015,177(2):151-174.
[17] Li M H,Zhang G Q,Lan S R,et al.A molecular phylogeny of Chinese orchids[J].Journal of Systematics and Evolution,2016,54(4):349-362.
[18] Christenson E A.An historical review of Saccolabium(Orchidaceae) and excluded species[J].Kew Bulletin,1986,41(4):833-853.
[19] 吉占和.中国兰科新植物和三个新记录属[J].植物研究,1995,15(1):43-46. Tsi Z H.A new taxon and three new record of Genera(Orchidaceae) from Yunnan,China[J].Bulletin of Botanical Research,1995,15(1):43-46.
[20] O'byrne P,Phoon S N,Ong P T.Pennilabium armanii:a new species from Peninsular Malaysia[J].Malesian Orchid,2009,3:113-116.
[21] Davis G L.Systematic embryology of the angiosperms[M].New York:Wiley,1966.
[22] Freudenstein J V,Rasmussen F N.Pollinium development and number in the Orchidaceae[J].American Journal of Botany,1996,83(7):813-824.
[23] Kant R.Development of anther and male gametophyte in some Indian orchids[D].Chandigarh:Panjab University,2007.
[24] Dressler R L.Features of pollinaria and orchid classification[J].Lindleyana,1986,1(2):125-130.
[25] Chen S C,Luo Y B.Notes on two confused genera:Gastrochilus and Saccolabium(Orchidaceae)[J].Acta Botanica Yunnanica,2007,29(2):167-168.
[26] Powo.Plants of the world online[EB/OL].Facilitated by the Royal Botanic Gardens,Kew.[2019-03-15].http://www.plantsoftheworldonline.org.
[27] Swamy B G L.Embryological studies in the Orchidaceae.Ⅰ.Gametophytes[J].The American Midland Naturalist,1949,41(1):184-201.
[28] Ravi K,Shilpa G.Development of Anther in Goodyera repens(L.)R.Br.:A Massulate Orchid[J].VEGETOS:An International Journal of Plant Research,2013,26(1):9-18.
[29] Gurudeva M R.Ontogeny of microsporangium and development of male gametophyte in Malaxis versicolor(LINDL.) Abeyw(Orchidaceae)[J].The Journal of Indian Botanical Society,2015,94(3-4):195-201.
[30] Kant R,Hossain M M.Development of pollinium in Malaxis muscifera(Lindl.) Kuntze[J].Bangladesh Journal of Botany,2011,39(2):193-198.
[31] Sood S K.Gametophytes,integuments initiation and embryogeny in Microstylis cylindrostachya(Orchidaceae,Epidendreae)[J].Proceedings:Plant Sciences,1985,95(6):379-387.
[32] Kant R,Kumar R K.Development of Anther in relation to Sectile Pollinium in Zeuxine strateumatica(Lindl.) Schltr[J].Journal of Biology and Life Sciences,2010,1:5-12.
[33] Sood S K.Embryology and systematic position of Liparis(Orchidaceae)[J].Plant Systematics and Evolution,1989,166(1-2):1-9.
[34] Sood S K,Rao P R M.Studies in the embryology of the diandrous orchid Cypripedium cordigerum(Cypripedieae,Orchidaceae)[J].Plant Systematics and Evolution,1988,160(3-4):159-168.
[35] Kant R,Hossain M M,Attri L K.Pollinium development in Spiranthes sinensis(Pers.) Ames.and Cymbidium pendulum SW:A comparative study[J].Bangladesh Journal of Botany,2014,42(2):307-314.
[36] Sriyot N,Thammathaworn A,Theerakulpisut P.Embryology of Spathoglottis plicata Blume:A reinvestigation and additional data[J].Tropical Natural History,2015,15(2):97-115.
[37] Sood S K.Embryology of Malaxis saprophyta,with comments on the systematic position of Malaxis(Orchidaceae)[J].Plant Systematics and Evolution,1992,179(1-2):95-105.
[38] Vij S P,Bhanwra R K,Dutt S,et al.Development of anther and male gametophyte in Rhynchostylis retusa Bl.(Orchidaceae)[J].Phytomorphology,2005,55(1-2):93-101.
[39] Vij S P,Kaur P,Bhanwra R K.Embryological studies in Epipactis gigantea(Orchidaceae)[J].Lindleyana,1999,14:74-81.
[40] Johri B M,Ambegaokar K B,Srivastava P S.Comparative embryology of angiosperms[M].New York:Springer-Verlag,1992.
[41] Arekal G D,Karanth K A.The embryology of Epipogium roseum(Orchidaceae)[J].Plant Systematics and Evolution,1981,138(1-2):1-7.
[42] Aybeke M.Anther wall and pollen development in Ophrys mammosa L.(Orchidaceae)[J].Plant Systematics and Evolution,2012,298(6):1015-1023.
[43] Wang L H,Tsay J S,Chi H S.Embryological studies on Spiranthes sinensis(Pers.) Ames[J].Flora,2016,224:191-202.
[44] Sood K.Gametogenesis,seed development and pericarp in Epipactis latifolia L.[J].Indian Botanical Society,1997,76:11-15.