(Anais da Academia Brasileira de Ciências (2017 (Annals of the Brazilian Academy of Sciences) Printed version ISSN 0001-3765 / Online version ISSN 1678-2690 http://dx.doi.org/10.1590/0001-3765201720170248 www.scielo.br/aabc | www.fb.com/aabcjournal Comparative pollen morphological analysis in the subgenera Passifloraand Decaloba TALIANE L. SOARES1, ONILDO N. JESUS1*, EVERTON H. SOUZA1,2, MÔNICA L. ROSSI3 and EDER J. OLIVEIRA1 1Embrapa Mandioca e Fruticultura, Rua Embrapa, s/n, Chapadinha, C.P. 007, 44380-000 Cruz das Almas, BA, Brazil 2Universidade Federal do Recôncavo da Bahia, Campus de Cruz das Almas, 44380-000 Cruz das Almas, BA, Brazil 3Universidade de São Paulo, CENA/USP, Av. Centenário, 303, São Dimas, 13400-970 Piracicaba, SP, Brazil Manuscript received on May 3, 2017; accepted for publication on June 8, 2017 ABSTRACT The genus Passiflora is the most diversified of the Passifloraceae, and its palynology presents wide morphological variability. The objective of the study was to evaluate the pollen morphology of 18 Passiflora species in order to identify informative pollinic characteristics to contribute to the taxonomic classification of the genus. The morphology of the pollen grains and the exine structure were investigated using light microscopy and scanning electron microscopy. Differences in the pollen morphology were found in the studied species, mainly in terms of shape, pollen aperture and ornamentation pattern of the exine. Most of the species belonging to the subgenus Passiflora presented ornamented 6-syncolpate pollen grains with an oblate-spheroidal shape and an exine with large lumens. In the subgenus Decaloba the pollen grains were 6-colporate, 12-colpate and 12-colporate, with subprolate to prolate-spheroidal shape, as well as an exine with smaller lumen size and few ornamented. The pollen morphology of the species of the subgenera Passiflora and Decaloba has shown palynological characteristics that have specific diagnostic value, thus allowing a better understanding of the taxonomy of the genus Passiflora. Key words: Passifloraceae, pollen grains, scanning electron microscopy, exine, morphological characterization. INTRODUCTION country (Bernacci et al. 2015). This genus was initially divided into 23 subgenera according to The genus Passiflora L. is the most representative Killip (1938) and subsequently reduced to only (of the Passifloraceae, with approximately 576 five:Astrophea (DC.) Mast., Deidamioides (Harms (.species (Ocampo and D’Eeckenbrugge 2017) from Killip, Decaloba (DC.) Rchb., Tetrapathea (DC the tropical and temperate regions of South America Reichb. and Passiflora L. (Feuillet and MacDougal Krosnick et al. 2013). Brazil has approximately 2003, Krosnick et al. 2009). However, the two) (species, and most of them are endemic in the largest subgenera are Passiflora (~ 250 species 150 .(and Decaloba (~ 230 species) (Porter-Utley 2014 Correspondence to: Onildo Nunes de Jesus E-mail: [email protected] Due to the great morphological diversity, pollen * Contribution to the centenary of the Brazilian Academy of grains have been used for taxonomic purposes, Sciences. assisting in the morphological characterization (An Acad Bras Cienc (2017 2 TALIANE L. SOARES et al. and identification of some species to generate 008, HURB-20753), P. edulis Sims f. flavicarpa phylogenetic information that more accurately Degener (BGP-038, HURB-20754), P. edmundoi expresses the origin and evolution of the organisms Sacco (BGP-046, HURB-20745), P. tenuifila Killip .Judd et al. 2007). The pollen characteristics are (BGP-105, HURB-20750), P. morifolia Mast) -fundamental for taxonomic classification because (BGP-107, HURB-20740), P. galbana Mast. (BGP .the pollen grains present the shape, size, color 109, HURB-20743), P. muchronata Sessé & Moc ,and ornamentation of the exine defined for each (BGP-114, HURB-20848), P. rubra L. (BGP-125 -species, genus and family (Mert 2010, Fazal et al. HURB-20752), P. suberosa L. (BGP-152, HURB ,(Silvério and Mariath 2014, Mezzonato-Pires 20742), P. foetida L. (BGP-153, HURB-20741 ,2013 ,(et al. 2015a, Silva et al. 2016). P. malacophylla Mast. (BGP-170, HURB-20747 .Passifloraceae is very interesting from the P. racemosa Brot. (BGP-172, HURB-20744), P palynological point of view because the pollen setacea L. (BGP-237, HURB-20755), P. cincinnata .grains present great phenotypic variability for Mast. (BGP-312, HURB-20746), P. maliformis L -several characteristics, some that have still not been (BGP-379, HURB-20756), P. subrotunda L. (BGP -explored according to systematic and phylogenetic 394, HURB-20751) and P. coccinea Aubl. (BGP aspects (Dettke and Santos 2009). Mohl (1834) 408, HURB-20748). These species belonging to (and Fritzsche (1837) were the first researchers to the Active Germplasm Bank of Passion fruit (AGP use the pollen morphology of Passiflora species from Embrapa Mandioca e Fruticultura located in for taxonomic purposes, highlighting the shape and Cruz das Almas, Bahia Brazil (12º 48’38’’S and ornamentation as good taxonomic characteristics. 39º06’26’’O; 220 m). Specimen of each taxon were Based on these studies, some other research have deposited in the HURB herbarium (Universidade focused on palynology in the differentiation of .(Federal do Recôncavo da Bahia Passiflora and/or species (Amela Garcia et al. In this study, we followed the two taxonomic 2002, Milward-de-Azevedo et al. 2010, 2014a, treatments of genus Passiflora proposed by Killip Gabarayeva et al. 2013, Mezzonato-Pires et al. 1938 (with emends by Escobar 1988, 1989, 1994; 2015a,b). However, few studies simultaneously and MacDougal 1994) by Feuillet and MacDougal analyzed different subgenera of the Passifloraceae as a point of comparison and discussion of (2003) Mezzonato-Pires et al. 2015b). Therefore, the) our data. Most of these species were preserved in objective of this work was to evaluate the pollen greenhouses, except for P. setacea, P. maliformis morphology of eighteen Passiflora species in order and P. alata, which were preserved under field to identify informative pollinic characteristics to conditions. Each Passiflora species was represented contribute to the taxonomic classification of the by one accession identified by the BGP code. genus. MORPHOPOLLINIC CHARACTERIZATION MATERIALS AND METHODS For the morphopollinic characterization, the PLANT MATERIAL pollen grains were fixed in modified Karnovsky’s ,(Eighteen Passiflora species, represented for two solution (Karnovsky 1965) [glutaraldehyde (2% subgenera according the classification of Feuillet paraformaldehyde (2%), CaCl2 (0.001 M), sodium and MacDougal (2003) were analyzed (Table cacodylate buffer (0.05 M), pH 7.2] for 48 hours I; Figure 1): Passiflora alata Curtis. (BGP- and then dehydrated in increasing concentrations HURB-20749), P. gibertii N. E. Br. (BGP- of ethanol (35-100%) for 20 minutes each. The ,004 (An Acad Bras Cienc (2017 POLLEN MORPHOLOGICAL OF SUBGENERA Passiflora and Decaloba 3 TABLE I List of 18 Passiflora peciess of the genus Passiflora L. used in this study. Supersection/section Compat.* Access Species Subgenus Pollinator 2n or series Systematic & Laurifolia (Cervi) Feuillet BGP-004 P. alata Curtis Passiflora L. MacDougal/ Quadrangulares Bees 18 SI Feuillet & MacDougal Stipulata Feuillet & P. gibertii N. MacDougal/ BGP-008 Passiflora L. Bees 18 SI E. Br. Granadillastrum Triana & Planch. P. edulis Sims f. BGP-038 Passiflora L. Passiflora/Passiflora Bees 18 SI flavicarpa Deg. Stipulata Feuillet & P. edmundoi BGP-046 Passiflora L. MacDougal /Kermesinae Hummingbirds 18 SI Sacco Killip ex Cervi BGP-105 P. tenuifilaKillip Passiflora L. Passiflora/Passiflora Bees 18 SC (Bryonioides (Harms P. morifolia Decaloba MacDougal & Feuillet/ BGP-107 Wasps 12 SC & Mast. D.C Rchb. Cieca (Medic.) MacDougal Feuillet Passiflora/Simplicifoliae BGP-109 P. galbana Mast. Passiflora L. Bats 18 SI Harms) Killip P. muchronata Passiflora/Simplicifoliae BGP-114 Passiflora L. Bats 18 SI Sessé & Moc. Harms) Killip Decaloba (DC.) MacDougal & Decaloba BGP-125 P. rubra L. Feuillet/ Wasps 12 SC D.C Rchb. Xerogona (Raf.) Killip Decaloba (DC.) MacDougal & Decaloba Feuillet/ BGP-152 P. suberosa L. Wasps 24 SC & D.C Rchb. Cieca (Medic.) MacDougal Feuillet Stipulata Feuillet & 18, 20, BGP-153 P. foetida L. Passiflora L. Bees SC MacDougal/Dysosmia DC. 22 P. malacophylla BGP-170 Passiflora L. Passiflora/Serratifoliae Bees 18 SI Mast. Stipulata Feuillet & P. racemosa BGP-172 Passiflora L. MacDougal/ Bees 18 SI Brot. Calopathanthus Harms Passiflora/Setaceae BGP-237 P. setacea L. Passiflora L. Bats 18 SI Killip ex Cervi P. cincinnata BGP-312 Passiflora L. Passiflora/Passiflora Bees 18 SI Mast. Laurifolia (Cervi) Feuillet & BGP-379 P. maliformis L. Passiflora L. MacDougal/Laurifoliae Killip Bees 18 SI ex Cervi BGP-394 P. subrotunda L. Passiflora L. Passiflora/Simplicifoliae Bees 18 SI Coccinea Feuillet & BGP-408 P. coccinea Aubl Passiflora L. Hummingbirds 18 SI MacDougal Taxonomic classification, their pollinators, diploid numbers, compatibility systematic, according to Feuillet and MacDougal .Melo et al. (2001), Melo and Guerra (2003), Soares et al. (2015). *SI = self-incompatible, SC = self-compatible ,(2003) (An Acad Bras Cienc (2017 4 TALIANE L. SOARES et al. ,Figure 1 - General view of flowers of 18 Passiflora species used in this study: a) P. alata, b) P. gibertii, c) P. edulis f. flavicarpa .d) P. edmundoi, e) P. tenuifila, f) P. morifolia, g) P. galbana, h) P. muchronata, i) P. rubra,