Flower nectar trichome structure of carnivorous plants from the genus butterworts Pinguicula L. (Lentibulariaceae)

Abstract

Pinguicula (Lentibulariaceae) is a genus comprising around 96 species of herbaceous, carnivorous plants, which are extremely diverse in flower size, colour and spur length and structure as well as pollination strategy. In Pinguicula, nectar is formed in the flower spur; however, there is a gap in the knowledge about the nectary trichome structure in this genus. Our aim was to compare the nectary trichome structure of various Pinguicula species in order to determine whether there are any differences among the species in this genus. The taxa that were sampled were Pinguicula moctezumae, P. moranensis, P. rectifolia, P. emarginata and P. esseriana. We used light microscopy, histochemistry, scanning and transmission electron microscopy to address those aims. We show a conservative nectary trichome structure and spur anatomy in various Mexican Pinguicula species. The gross structural similarities between the examined species were the spur anatomy, the occurrence of papillae, the architecture of the nectary trichomes and the ultrastructure characters of the trichome cells. However, there were some differences in the spur length, the size of spur trichomes, the occurrence of starch grains in the spur parenchyma and the occurrence of cell wall ingrowths in the terminal cells of the nectary trichomes. Similar nectary capitate trichomes, as are described here, were recorded in the spurs of species from other Lentibulariaceae genera. There are many ultrastructural similarities between the cells of nectary trichomes in Pinguicula and Utricularia.

Living between land and water – structural and functional adaptations in vegetative organs of bladderworts

“…Semi-thin sections (0.9-1.0 μm thick) were prepared and stained with aqueous methylene blue / azure II (MB/AII) for 1-2 min (Humphrey and Pittman 1974). Additional material was fixed as above, embedded in Technovit 7100 (Kulzer, Germany) and processed as in Lustofin et al (2020). Sections were examined and photographed using a Nikon Eclipse E400 microscope with a Nikon DS-Fi2 camera and NIS-Elements D 4.00.00 4.0 software (Nikon, Tokyo, Japan) and using an Olympus BX60 microscope with an Olympus XC50 digital camera and cellSens Standard Software (Olympus, Tokyo, Japan).…”

Effects of crossing distance on fitness components in the carnivorous plant Pinguicula moranensis (Lentibulariaceae)

“…For example, the relatively large, colored corollas bearing nectar guides could be involved in the attraction of flower visitors (García et al, 1994;Molau, 1993). In addition, the spurred corollas could favor the interaction with long-tongue pollinators (García et al, 1994;Lustofin et al, 2019;Molau, 1993). Finally, flowers exhibit herkogamy, a mechanism that enhances outcrossing (Molano-Flores et al, 2018;Villegas & Alcalá, 2017).…”

“…Pinguicula L. is a genus comprised of nearly 100 species (Ellison et al, 2003) recognized as a member of the extant carnivorous lineages (Casper, 1966;Legendre, 2000). This genus has spurred zygomorphic flowers that majorly depend on long-tongued insects for fruit production (García, Antor, & Villar, 1994;Lustofin, Świątek, Miranda, & Płachno, 2019;Molano-Flores et al, 2018;Molau, 1993;Zamora, 2002). Xenogamous and selfcompatible species have been commonly reported, but see Molau (1993) for autogamy in P. villosa.…”

Life in the Current: Anatomy and Morphology of Utricularia neottioides

“…Material of both Utricularia species was fixed and later processed as in Lustofin et al [ 37 ]: materials were fixed in a mixture of 2.5% or 5% glutaraldehyde with 2.5% formaldehyde in a 0.05-M cacodylate buffer (Sigma-Aldrich, Sigma-Aldrich Sp. z o.o.…”