Plant Systematics and Evolution (2018) 304:981–993 https://doi.org/10.1007/s00606-018-1526-z ORIGINAL ARTICLE Pollen morphology in Brazilian species of Gloxiniinae (Gesneriaceae): variation in apertures and pattern of ornamentation Cintia N. de Souza1 · Andréa O. de Araujo2 · Alain Chautems3 · Maria A. V. da Cruz‑Barros4 · Eduardo C. Gasparino1 Received: 20 February 2018 / Accepted: 4 June 2018 / Published online: 30 June 2018 © Springer-Verlag GmbH Austria, part of Springer Nature 2018 Abstract Gloxiniinae comprises herbs and subshrubs usually growing on rocky outcrops, rocky felds or gallery forests. For Gesne- riaceae in some cases variations in pollen morphology allow the diferentiation of genera and species. We studied the pol- len grains of ten Brazilian species of Gloxiniinae (Gesneriaceae), including the genera Chautemsia, Gloxinia, Goyazia, Mandirola and Seemannia with the purposes of describing the pollen morphology of these genera, and contributing to the taxonomic characterization of the group and a better delimitation of genera and species of Gesneriaceae. The pollen grains were acetolyzed, measured, photographed and described qualitatively. Quantitative data were analyzed through descriptive and multivariate statistics. Non-acetolyzed pollen grains were observed in SEM and TEM in order to provide more details of the ornamentation and the structure of the exine. The analyzed species difer as to the pollen amb, shape, length, width and ends of colpi, presence or absence of margo, type of endoaperture and exine ornamentation. We found circular, subcircular and subtriangular amb, oblate spheroidal and subprolate shape, long or very long colpi, narrow, wide or very wide, with or without margo, lalongate or lolongate endoaperture in microreticulate or reticulate pollen grains. The reticulate ornamenta- tion appears in the Gloxinia species’ pollen grains, and lolongate endoapertures represent the pattern for the subtribe pollen grains except in Chautemsia. The pollen grain metrics examined by principal component analysis allow generic distinction. We conclude that qualitative and quantitative pollen data help to delimit the genera and species of Gloxiniinae. Keywords Endoaperture · Exine · Gesnerieae · Multivariate analysis · Palynotaxonomy · Pollen grains Handling editor: Ricarda Riina. Electronic supplementary material The online version of this article (https​://doi.org/10.1007/s0060​6-018-1526-z) contains supplementary material, which is available to authorized users. * Cintia N. de Souza 2 Centro de Ciências Naturais e Humanas, UFABC – [email protected] Univ. Federal do ABC, Rua São Paulo, s/nº ‑ Jardim Antares, São Bernardo do Campo, SP 09606‑070, Brazil Andréa O. de Araujo [email protected] 3 Laboratoire de Systématique Végétale et Biodiversité, Conservatoire et Jardin botaniques de la Ville de Genève Alain Chautems & Université de Genève, CP 71, 1292 Chambésy, Geneva, alain.chautems@ville‑ge.ch Switzerland Maria A. V. da Cruz‑Barros 4 Instituto de Botânica, Núcleo de Pesquisas em Palinologia, [email protected] Av. Miguel Stéfano, 3687 Água Funda, São Paulo, Eduardo C. Gasparino SP 04045‑972, Brazil [email protected] 1 Departamento de Biologia Aplicada à Agropecuária, Faculdade de Ciências Agrárias e Veterinárias (FCAV), UNESP—Univ. Estadual Paulista, Via de Acesso Prof. Paulo Donato Castellane, s/n, Jaboticabal, SP 14884‑900, Brazil Vol.:(0123456789)1 3 982 C. N. Souza et al. Introduction In this context, this study intends to characterize the pol- len grains in Brazilian species of Gloxiniinae (Gesneriaceae) Gesneriaceae Rich & Juss. ex DC. includes some 147–148 with the purpose of describing the pollen morphology of genera and 3260–3435 species, with a wide distribution these genera, contributing to the taxonomic characterization in the tropical regions and few representatives in the tem- of the group and a better delimitation of genera and species. perate regions. The family centers of diversity are located in northwestern South America (Colombia to Ecuador) and also in southeastern Brazil (Chautems 1991; Souza Materials and methods and Lorenzi 2012; Weber 2004; Weber et al. 2013). All Neotropical species are included in the subfamily Gesne- We analyzed the pollen grains of ten Brazilian species rioideae, where we fnd the tribe Gesnerieae and the sub- of Gloxiniinae (Gesneriaceae): Chautemsia A.O.Araujo tribes Gesneriinae, Gloxiniinae, Columneinae, Sphaeror- & V.C.Souza (Chautemsia calcicola A.O.Araujo & rhizinae and Ligeriinae (Weber et al. 2013). V.C.Souza), Gloxinia L’Hér. (Gloxinia alterniflora The Gloxiniinae is composed of 21 genera and 160 A.O.Araujo & Chautems; G. erinoides (DC.) Roalson & species, comprising the genera previously treated in the Boggan; G. perennis Fritsch), Goyazia Taub. (Goyazia pet- traditional Gloxinieae tribe (sensu Roalson et al. 2005a, raea (S.M.Phillips) Wiehler; G. rupicola Taub.), Mandirola b; Wiehler 1983). In Brazil, Gloxiniinae is represented by Decne. (Mandirola hirsuta (DC.) A.O.Araujo & Chautems; 15 species, distributed in eight genera, three of them are M. multifora (Gardner) Decne.; Mandirola rupestris (Gard- endemic to the country. These species are mostly found on ner) Roalson & Boggan) and Seemannia Regel (Seemannia rocky outcrops, rocky felds or gallery forests in the Cer- sylvatica (Kunth) Hanst.) (Fig. 1). However, only the ten rado biome, growing as perennial herbs or subshrubs, with species mentioned above were studied in the present study, scaly rhizomes, leaves opposite and thin, fowers mostly because for the other fve species belonging to the Gloxi- purple, sometimes white or red, and dry or feshy capsule niinae subtribe: Diastema Benth. (Diastema racemiferum (Araujo 2007; Weber 2004; Weber et al. 2013). Benth.); Goyazia Taub. (Goyazia villosa (Gardner) R.A. Molecular studies such as that conducted by Smith (1996, Howard); Monopyle Moritz ex Benth. & Hook.f. (Mono- 2000), Smith et al. (1997), Citerne et al. (2000), Zimmer pyle refexa (Rusby) Roalson & Boggan); Phinaea Benth. et al. (2002), Mayer et al. (2003), Perret et al. (2003), Roal- (Phinaea albolineata (Hook.) Benth. ex Hemsl.); and See- son et al. (2005a, b) and Clark et al. (2006, 2012) discussed mannia Regel (Seemannia purpurascens Rusby) there were the monophyly of groups within Gesneriaceae and reconsid- not available material. For the pollen morphology analysis, ered the placement of some species, genera or even tribes. we used at least two fowers of each specimen, and for each Roalson et al. (2005a) and Zimmer et al. (2002) based studied species, a “standard” specimen was chosen for pres- on phylogenetic analysis suggested that the genera in entation of the descriptions and illustrations. These standard Gloxiniinae were not monophyletic, especially Gloxinia specimens are indicated by asterisks in the description of L’Hér, thus pointing to the need for reconsidering the the material used (Online Resource 1). The pollen material taxonomy of the group (Araujo et al. 2012). So the gen- was obtained from fowers in anthesis from exsiccates or in era Gloxinia, Goyazia Taub., Mandirola Decne. and See- alcohol 70% deposited in the herbaria ESA, G, HUFABC, mannia Regel were reviewed and reorganized by Roalson SP and UEC (acronyms according to Thiers (2016), continu- et al. (2005a). In addition, the studies of Boggan et al. ously updated). (2008) and Araujo et al. (2010a, b) added new descriptions In light microscopy analysis, pollen grains were acetol- of genera and species, contributing to a clearer taxonomic yzed according to Erdtman (1960), with modifcations pro- characterization of the subtribe. posed by Melhem et al. (2003). We measured the diameters The pollen morphology of some Gloxiniinae species in polar and equatorial views (n = 25) and pollen aperture was analyzed by Howard (1975), Williams (1978), Fil- and exine thickness (n = 10) up to 7 days after their prepara- ice et al. (1981), Xifreda (1996) and Gasparino (2008). tion (Melhem and Matos 1972; Salgado-Labouriau 1973), Gasparino et al. (2010) summarized some palynological and the slides were deposited in the pollen reference collec- studies of Gesneriaceae, emphasizing the importance of tion of the Plant Morphology and Palynology Laboratory, pollen morphology for taxa circumscription. Besides the Departamento de Biologia aplicada à Agropecuária, Uni- recently developed studies based on molecular characters, versidade Estadual Paulista, Unesp, Jaboticabal, Brazil. For pollen morphology studies represent an additional tool for scanning electron microscopy analysis (SEM), non-acetol- improving delimitation of genera and species in Gesne- yzed pollen grains were prepared according to Melhem et al. riaceae, as advocated by Fritze and Williams (1988) and (2003), and for transmission electron microscopy analysis Gasparino et al. (2011). (TEM), we followed the protocols of Haddad et al. (1998) and Sabatini et al. (1963). 1 3 Pollen morphology in Brazilian species of Gloxiniinae (Gesneriaceae) 983 Fig. 1 Overview of the morphological diversity of Brazilian species (Araujo et al. 545). f Mandirola hirsuta (Araujo et al. 1139). g–h of Gloxiniinae. a Chautemsia calcicola (Araujo et al. 500). b Glox- Mandirola multifora (Araujo et al. 1111; Araujo et al. 1128). i Man- inia perennis (Araujo et al. 468). c Gloxinia erinoides (Araujo et al. dirola rupestris (Araujo et al. 1104). j Seemannia sylvatica (Araujo 501). d Goyazia petraea (Araujo et al. 1065-24). e Goyazia rupicola et al. 750) Means (x), standard deviation (sx),