Comparative pollen morphological analysis in the subgenera Passiflora and Decaloba

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.

Taxonomic study of subfamily Nepetoideae (Lamiaceae) by polynomorphological approach

“…The pollinic features observed through LM and SEM are valuable to differentiate and establish the relationships between the species (Santos Amorim et al, ) because they were genetically determined and very constant and specific to each species (e.g., exine sculpturing, aperture type, and number) and have a significant taxonomic value (Mert, ; Soares, Jesus, Souza, Rossi, & Oliveira, ). Based on aperture number and nuclei in pollen, Lamiaceae was divided into two groups Lamioideae and Nepetoideae (Erdtman, ).…”

Flora polínica da Área de Proteção Ambiental Serra Branca/Raso da Catarina, Jeremoabo, Bahia, Brasil – Família: Passifloraceae

“…3,7. Comentários: As observações realizadas neste estudo para Passiflora cincinnata, são semelhantes às de Verdaska et al 2013e Soares et al (2018) quanto ao tipo e número de aberturas, ou seja, grãos de pólen 6-sincolpados. Já para Araújo e Santos (2004) e Araújo et al 2019, os grãos de pólen dessa espécie são heteromórficos, apresentando aberturas variando de 6-(8)-sincolpadas, enquanto para Presting (1965) estes são 6-colporoidados (em espécimes ocorrentes na Bolívia) e 8-colpados (em espécimes da Colômbia).…”

“…Com relação ao tamanho os grãos de pólen estudados por Evaldt et al (2011), são menores que os do espécime aqui examinado. Para Soares et al (2018), espécimes de P. foetida são polinizados por abelhas. Segundo Nunes e Queiroz (2006), na Bahia, a espécie ocorre praticamente em todo o Estado e em todos os tipos vegetacionais, comportandose como uma planta invasora em áreas degradadas.…”

“…Passifloraceae mostra-se uma família muito diversa do ponto de vista palinológico. Palinologicamente, começou a ter seus grãos de pólen estudados no decorrer do século XIX (Mohl, 1834;Fritzsche, 1837;Fischer, 1890), sendo posteriormente analisados por diversos outros autores (Erdtman, 1952;Presting, 1965;Spirlet, 1965;Huynh, 1972;Roubik;Moreno, 1991;Carreira, 1977;Amela-García et al, 2002;Melhem et al, 2003;Santos, 2004;Barrios et al, 2005;Milward-de-Azevedo et al, 2004, 2010, 2014Dettke;Santos, 2009;Evaldt et al, 2011;Verdasca et al, 2013;Borges;Mezzonato-Pires et al, 2015Soares et al, 2018;Araújo et al, 2019). Todos são unânimes ao descrever os grãos de pólen da família com grande variabilidade de características, especialmente os do gênero Passiflora, destacando a importância do entendimento apertural para a interpretação morfopolínica das espécies.…”

The phenotypic plasticity of of Picea omorika /Panc./Purkyne morphological pollen traits

“…Apart from physiological, morphological traits of pollen are those that directly affect the pollen germination capacity, fertilization and further reproduction and indirectly the growth and development of plants (KIRK, 1993;DE LEONARDIS et al, 1995;FERRAUTO et al, 2015), which makes them extremely important in the controlled selection of high-quality genotypes -pollinator trees. The study of morphological traits of pollen grains is of great importance in the systematics and taxonomy of plants (SHAH et al, 2005;PANAHI et al, 2012;WRONSKA-PILAREK et al, 2016;JIA et al, 2014;SOARES et al, 2017), as well as in the analyses carried out to determine the somatic or gametophytic ploidy level (DE STORME et al, 2013). The study of pollen morphology (its dimensions, surface area, volume, surface structure) is also relevant from the aspect of global climate change (KNIGHT et al, 2005).…”