Exine morphometric analysis as a new tool for Citrus species identification: a case study from Oplontis (Vesuvius area,
- PDF / 2,320,756 Bytes
- 10 Pages / 595.276 x 790.866 pts Page_size
- 42 Downloads / 197 Views
ORIGINAL ARTICLE
Exine morphometric analysis as a new tool for Citrus species identification: a case study from Oplontis (Vesuvius area, Italy) Maria Rosaria Barone Lumaga1 · Elda Russo Ermolli2 · Bruno Menale1 · Stefano Vitale2 Received: 30 October 2018 / Accepted: 23 January 2020 © Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract In the Mediterranean area, the occurrence of citrus plants in ancient times is clearly attested in Sardinia and along the southern Tyrrhenian coasts through the presence of pollen grains and organic residues dating back to the sixth century bc. The presence of Citrus pollen was also detected in soil sediments from Pompeii (ad 79), in marine sediments from the ancient harbour of Naples (first century ad), in Rome (27 bc–ad 14) as well as in a garden soil at the Villa di Poppea in Oplontis (first century bc). The first citrus tree to be identified was citron (Citrus medica L.), but even if the presence of other citrus species was supposed, identification was limited by the difficulty of discriminating the exine characteristics through optical microscopy. Exine micromorphology of eight citrus species, including primitive to cultivated, was studied by SEM and optical microscope observations. By means of the image analysis method, the morphometry of lumina and brochi was evaluated. Results indicate that the size of lumina and brochi increases from primitive, wild to cultivated citrus up to lemon. In addition, there is an overall correspondence between brochi dimension and hybridization history. The morphometric analysis on modern pollen material and comparison with the fossil grains found at Oplontis allowed attesting for the first time the presence of C. limon and C. reticulata in the Roman Age. The statistical methods used for the analysis of exine ornamentations proved to be a useful tool for interpreting the complex citrus hybridization history and for shedding light on the scenario of citrus fruits introduction in the Roman period. Keywords Pollen · Image analysis · Roman age · Lemon · Mandarin
Introduction Pollen characters have been considered useful in defining evolutionary trends in plant families (e.g. Araceae, Grayum 1986; Fabaceae, Ferguson and Skvarla 1982) and, in particular, exine micromorphology has frequently been used as a reference character in taxonomical and phylogenetic analyses. Grant et al. (2000) carried out a study on Aurantioideae (Rutaceae, including Citrus) pollen based on size, Communicated by F. Bittmann. * Elda Russo Ermolli [email protected] 1
Dipartimento Di Biologia, Orto Botanico, Università Degli Studi Di Napoli Federico II, Via Foria 223, 80139 Napoli, Italy
Dipartimento Di Scienze Della Terra, Dell’Ambiente E Delle Risorse (DiSTAR), Università Degli Studi Di Napoli Federico II, Via Cintia 21, 80126 Napoli, Italy
2
general morphology, and number of apertures and confirmed a general congruence between morphology and classification (Swingle and Reece 1967). Other studies were focused on exine micromorphology in Citrus but o
Data Loading...
