Maria Rosaria Barone Lumaga

Pseudodioon akyoli gen. et sp. nov., an extinct member of Cycadales from the Turkish Miocene

Fossil cycadalean leaves recorded from the Miocene plant assemblage of Soma, western Turkey, are described and assigned to an extinct genus and species, Pseudodioon akyoli. Leaf macromorphology suggests affinity with members of the Zamiaceae (subfam. Encephalartoideae), particularly with modern Dioon. Micromorphological features on the other hand indicate affinity with modern Cycas (Cycadaceae). Ordinary cells on the adaxial epidermis are isodiametric and are not differentiated into thick- and thin-walled cells. This is similar to Encephalartoideae-like fossils reported from the Cenozoic of the Northern Hemisphere, and even from the Mesozoic. Shared macromorphological traits of P. akyoli and other coeval Encephalartoideae-like fossil cycadalean leaves from Europe suggest that an extinct group of cycads inhabited southern Europe from the western part of Turkey, through Greece and France to Switzerland in the north during the Oligo-Miocene.

Aperture evolution in Nymphaeaceae: insights from a micromorphological and ultrastructural investigation

Abstract The evolution of the apertural type in the ANITA-grade family Nymphaeaceae, despite the importance of pollen characters for both palaeobotanical and neobotanical investigations, has not been yet totally understood. To elucidate some unclear aspects regarding the homologies of the apertural condition in basal and core Nymphaeaceae, we examined the pollen grains from five species of this family. We offer for the first time some evidence about the presence of a proper operculum in the pollen grain of Nuphar and for the ring-like status of the aperture of Nymphaea caerulea and Victoria cruziana. Our findings clarify and reinforce the hypothesis of an opercular origin of the distal part of the pollen grain in the core Nymphaeaceae and support the paraphyly of the genus Nymphaea as emerged from recent molecular studies. The diversity and specialisation of this ‘basal’ family is underlined even by its pollen characters.

Low pollination success of hybrids between nectar-rewarding and food-deceptive orchids

Natural hybridization is widespread among food-deceptive orchids, whereas hybridization between deceptive and rewarding species is less common among Mediterranean species and its evolutionary consequences remain under-investigated. Here, we examine the morphological variation in floral traits, pollination success and demographic dynamics of natural hybrids between the widespread nectar-rewarding Anacamptis fragrans and the Mallorca endemic, food-deceptive A. robusta. We confirmed the status of hybrids using ribosomal DNA and assessed their maternal contribution using length polymorphism in the plastid tRNALEU intron. Genetic analyses confirmed that hybridization occurred in both directions, but the hybrids were morphologically closer in floral metric characters to A. fragrans and exhibited reduced among-individual variation in floral traits. No obvious secreting papillae were present in the hybrid spur, which more closely resembled the spur of non-rewarding A. robusta, reinforcing field observations that hybrids were probably nectarless. Compared with both rewarding and deceptive parents, the hybrids were less attractive for pollinators, most likely because of the absence of significant reward and of their combination of contrasting parental floral advertisements. In spite of its low pollination success, the hybrid population is presently expanding alongside the endemic A. robusta, suggesting that it follows the demographic dynamics of the parental species.

Heterotrophic components of biofilms on wood artefacts

Heterotrophic components of biofilms on wood artefacts were studied at the Conservation Laboratory for Wood Artefacts of the University Suor Orsola Benincasa of Naples, Italy. The aim of the study was to add new information on the micro-habitats represented by biofilms formed by wood-dwelling organisms. Light and electron microscopy of histological features of woods used to make the artefacts showed that the woods belonged to species of lime (Tilia sp.), poplar (Populus sp.) and pear (Pyrus sp.). A Denaturing Gradient Gel Electrophoresis analysis performed on heterotrophic microorganisms colonizing the artefacts led to identify four species of bacteria, namely Bacillus cereus, B. mycoides, B. subtilis and Microbacterium oleivorans, and seven species of fungi, namely Alternaria alternata, Aspergillus fumigans, A. versicolor, Cladosporium cladosporioides, C. oxysporum, Fusarium oxysporum and Penicillium chrysogenum. Based on its morphological features, an insect found on some artefacts was identified as the xylophagous beetle Nicobium castaneum (Anobiidae). The influence of wood type and environmental conditions on the diversity of microorganisms was discussed.

Exine micromorphology and ultrastructure in Neottieae (Epidendroideae, Orchidaceae)

The diverse epidendroid orchid tribe Neottieae is characterized by multiple transitions between autotrophy and mycoheterotrophy, allogamous and autogamous mating systems, pollen released as tetrads or monads, and pollen exine tectate or semitectate. We use transmission and scanning electron microscopy on pollen of ten species of Neottieae to investigate whether the differences in pollen aggregation and exine micromorphology and ultrastructure reflect phylogenetic relationships, or whether this variation is subject to ecological constraints. Our results showed that differences in exine micromorphology are mostly concordant with phylogenetic relationships in Neottieae, i.e. an ascending tendency of pollen ornamentation from tectate (Cephalanthera) to semitectate (e.g. Neottia). In contrast, pollen aggregation, when plotted on the most recent phylogeny, shows repeated transitions between monads and tetrads that could be related to ecological constraints. Tetrads are present in species that are nectar rewarding, whereas monads are common in deceptive species. Cephalanthera is characterized by recalcitrant pollen, including the frequent occurrence of collapsed pollen. In this genus, the observed shifts from allogamous to autogamous or cleistogamous mating systems could help to reduce pollen damage caused by exposure to dry habitats.