Ultrastructure of Heterocolpate Pollen in Cryptantha (Boraginaceae)

Abstract

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Pollen morphology of the genusOmphalodesMill. (Cynoglosseae, Boraginaceae)

“…Overall, the results obtained agreed with previous descriptions (Liu et al, 2001;Hargrove & Simpson, 2003;Bigazzi et al, 2006), despite some varied values, most probably due to different methodologies (e.g. Barbier & Mathez, 1973;Díez & Valdés, 1991;Buchner & Halbritter, 2011).…”

“…The heterocolpate condition was constant in all the species of Omphalodes studied, as well as in other taxa of Cynoglosseae (Anh & Lee, 1986;Valdés, 1987;Díez & Valdés, 1991;Hargrove & Simpson, 2003;Coutinho et al, unpublished results) being, most probably, an apomorphic condition for Omphalodes and Cynoglosseae (Hargrove & Simpson, 2003). Three functions have been proposed for the heterocolpate condition: Points for pollen tube growth, points for the exchange of physiologically active substances and harmomegathy (Muller, 1979), the latter being solely associated with pseudocolpi (Hargrove & Simpson, 2003). In Omphalodes, harmomegatic reactions are indeed facilitated by the presence of pseudocolpi that enable the accommodation of volume changes after (de)hydration, and by a thin exine that increases the flexibility of the pollen grain (Bolick, 1981;Payne, 1981).…”

“…The existence of a ring-like aperture has already been described for some genera of Cynoglosseae (e.g. Cryptantha, Paracaryum, Rindera and Solenanthus; Hargrove & Simpson, 2003;Bigazzi et al, 2006), but was never reported for Omphalodes up to now (e.g. Barbier & Mathez, 1973).…”

Palynological contribution to the systematics ofRinderaand the allied generaParacaryumandSolenanthus (Boraginaceae-Cynoglosseae)

“…Mey., Lappula Moench, Asperugo L. and others), but within Cynoglosseae known only from Omphalodes Mill. (Clarke 1977, Díez & Valdés 1991, Popova & Zemskova 1995, Hargrove & Simpson 2003.…”

Flora polínica da reserva do parque estadual das fontes do Ipiranga (São Paulo, SP, Brasil). Famílias: 141-Boraginaceae e 149-Gesneriaceae

“…1987, Moncada & Herrera 1988, Miranda & Andrade 1990, Nowicke & Miller 1990, Diez & Valdes 1991, Palácios-Chavez et al 1991, Roubik & Moreno 1991, Ning et al 1995, Perveen et al 1995, Scheel & Barth 1995, Scheel et al 1996, Quiroz-Garcia et al 1997, Hargorve & Simpson 2003, Melhem et al 2003, Melo et al 2006, Maggi et al 2008, Binzet & Orcan 2009, Gasparino & Cruz-Barros 2009, Binzet et al 2010.…”