The embryology of Prionium serratum (L.f.) Drege ex E.Mey. (Juncaceae:Cyperales) and its implications for the phylogeny of Cyperales

dc.contributor.authorMunro, Sioban Lucille
dc.date.accessioned2023-09-18T13:09:54Z
dc.date.available2023-09-18T13:09:54Z
dc.date.issued1996
dc.date.updated2023-09-18T13:08:44Z
dc.description.abstractThis study investigates the phylogenetic placement of Prionium serratum, a monotypic genus in the family Juncaceae and the consequences of this on the evolutionary relationships of Cyperales using embryology, morphology and rbcL sequence data. The embryology of Prionium conforms to that found in Juncaceae. The tapetum is glandular-secretory and microsporogenesis is simultaneous. Pollen is united in tetrahedral and cross tetrads and is tri-nucleate at release. The ovary is trilocular, there are three stigmata and the style is absent. There are many ovules per locule and placentation is axile. The ovule is anatropous, bitegmic and crassinucellate. The embryo sac conforms to the Polygonum type of development. Endosperm formation is helobial and embryogeny is of the Onagrad type, Juncus variation. The mature embryo is linear in shape and is embedded within the endosperm. The seed is trigonal, lacks processes and the seed coat is formed from both integuments. Germination is epigeal and the seedlings are of Type A. Phylogenetic analyses using morphological data (including embryology) and total evidence (rbcL sequence data combined with morphological data) revealed that Juncaceae are paraphyletic with Prionium basal to Juncaceae plus Cyperaceae within Cyperales in both instances. In addition, Oxychlae is basal to Cyperaceae in the total evidence analysis. The basal placement of Prianium within Cyperales is supported by its woody habit, carpels fused in the ovary region chlorenchymatous air canals in the leaf and the absence of air canals between vascular bundles. The total evidence phylogeny is in agreement with Plunkett et al.'s (1995) rbcL topology and this study also supports Cutler's (1969) contention that Prianium should be excluded from Juncaceae. Therefore, it is suggested that Prianium be elevated to family status.
dc.identifier.apacitationMunro, S. L. (1996). <i>The embryology of Prionium serratum (L.f.) Drege ex E.Mey. (Juncaceae:Cyperales) and its implications for the phylogeny of Cyperales</i>. (). ,Faculty of Science ,Department of Biological Sciences. Retrieved from http://hdl.handle.net/11427/38738en_ZA
dc.identifier.chicagocitationMunro, Sioban Lucille. <i>"The embryology of Prionium serratum (L.f.) Drege ex E.Mey. (Juncaceae:Cyperales) and its implications for the phylogeny of Cyperales."</i> ., ,Faculty of Science ,Department of Biological Sciences, 1996. http://hdl.handle.net/11427/38738en_ZA
dc.identifier.citationMunro, S.L. 1996. The embryology of Prionium serratum (L.f.) Drege ex E.Mey. (Juncaceae:Cyperales) and its implications for the phylogeny of Cyperales. . ,Faculty of Science ,Department of Biological Sciences. http://hdl.handle.net/11427/38738en_ZA
dc.identifier.ris TY - Master Thesis AU - Munro, Sioban Lucille AB - This study investigates the phylogenetic placement of Prionium serratum, a monotypic genus in the family Juncaceae and the consequences of this on the evolutionary relationships of Cyperales using embryology, morphology and rbcL sequence data. The embryology of Prionium conforms to that found in Juncaceae. The tapetum is glandular-secretory and microsporogenesis is simultaneous. Pollen is united in tetrahedral and cross tetrads and is tri-nucleate at release. The ovary is trilocular, there are three stigmata and the style is absent. There are many ovules per locule and placentation is axile. The ovule is anatropous, bitegmic and crassinucellate. The embryo sac conforms to the Polygonum type of development. Endosperm formation is helobial and embryogeny is of the Onagrad type, Juncus variation. The mature embryo is linear in shape and is embedded within the endosperm. The seed is trigonal, lacks processes and the seed coat is formed from both integuments. Germination is epigeal and the seedlings are of Type A. Phylogenetic analyses using morphological data (including embryology) and total evidence (rbcL sequence data combined with morphological data) revealed that Juncaceae are paraphyletic with Prionium basal to Juncaceae plus Cyperaceae within Cyperales in both instances. In addition, Oxychlae is basal to Cyperaceae in the total evidence analysis. The basal placement of Prianium within Cyperales is supported by its woody habit, carpels fused in the ovary region chlorenchymatous air canals in the leaf and the absence of air canals between vascular bundles. The total evidence phylogeny is in agreement with Plunkett et al.'s (1995) rbcL topology and this study also supports Cutler's (1969) contention that Prianium should be excluded from Juncaceae. Therefore, it is suggested that Prianium be elevated to family status. DA - 1996 DB - OpenUCT DP - University of Cape Town KW - botany LK - https://open.uct.ac.za PY - 1996 T1 - The embryology of Prionium serratum (L.f.) Drege ex E.Mey. (Juncaceae:Cyperales) and its implications for the phylogeny of Cyperales TI - The embryology of Prionium serratum (L.f.) Drege ex E.Mey. (Juncaceae:Cyperales) and its implications for the phylogeny of Cyperales UR - http://hdl.handle.net/11427/38738 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/38738
dc.identifier.vancouvercitationMunro SL. The embryology of Prionium serratum (L.f.) Drege ex E.Mey. (Juncaceae:Cyperales) and its implications for the phylogeny of Cyperales. []. ,Faculty of Science ,Department of Biological Sciences, 1996 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/38738en_ZA
dc.language.rfc3066eng
dc.publisher.departmentDepartment of Biological Sciences
dc.publisher.facultyFaculty of Science
dc.subjectbotany
dc.titleThe embryology of Prionium serratum (L.f.) Drege ex E.Mey. (Juncaceae:Cyperales) and its implications for the phylogeny of Cyperales
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationlevelMSc
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