New Cytogenetic Data for the Neottieae Tribe (Orchidaceae) in the Mediterranean Region.

This work presents a summary of cytogenetic data, including new information, on several species within the tribe Neottieae, with an update of the karyotype for 23 species belonging to the genera Cephalanthera, Limodorum, Epipactis, and Neottia (including Listera). Each of these four genera also presents distinctive chromosomal features, such as bimodal karyotypes. Our research includes insights into the distribution of constitutive heterochromatin, measured using C-banding and, in some cases, specific fluorochromes for the detection of A-T- and G-C-rich DNA. In the Epipactis group, it is noteworthy that when using the Giemsa banding technique, certain species (e.g., E. placentina, E. meridionalis) with a chromosome number of 2n = 38 were observed to exhibit a conspicuous wide band of constitutive heterochromatin on the long arm of the third pair in a subcentromeric position, resembling what has been observed in E. helleborine. These differences also have the potential to contribute to the diversification of these species. Based on the karyological results obtained, a hypothesis regarding the origin of certain species within the E. helleborine group is proposed. Additionally, karyological analyses conducted on a specimen of E. microphylla revealed chromosome counts ranging from 36 to 40. Somatic metaphases exhibited evident structural alterations in certain chromosomes, showing rearrangements probably caused by translocation phenomena. Based on the data obtained from the species within the studied genera, it is conceivable that variations in chromosomes, both structurally and in the distribution of constitutive heterochromatin, exert a significant influence on the evolution of the karyotype. Moreover, in many entities belonging to the Neottieae tribe, these processes may also contribute to the diversification of the phenotype in some instances.

Comparative Cytogenetic of the 36-Chromosomes Genera of Orchidinae Subtribe (Orchidaceae) in the Mediterranean Region: A Summary and New Data.

This article provides a summary of the current knowledge on the cytogenetics of four genera, which are all composed of 36 chromosomes, within the Orchidinae subtribe (Orchidaceae). Previous classical studies have revealed differences in karyomorphology among these genera, indicating genomic diversity. The current study includes an analysis of the current knowledge with an update of the karyotype of 47 species with 36 chromosomes from the genera Anacamptis, Serapias, Himantoglossum, and Ophrys. The study discusses comparisons of karyotypes among these genera that used traditional techniques as well as karyotype asymmetry relationships with various asymmetry indices. Additionally, the study reports new findings on polyploidy in Anacamptis pyramidalis and Serapias lingua, which were observed through karyotype and meiotic metaphase analyses in EMC. Moreover, the study detected B chromosomes for the first time in A. papilionacea and A. palustris. The article also describes the use of fluorescent in situ hybridization in some specimens of A. papilionacea and A. collina to locate different sites of the 18S-5.8S-25S rDNA and 5S rDNA ribosomal complexes on chromosomes. The information derived from these cytogenetic analyses was used to refine the classification of these orchids and identify evolutionary relationships among different species and genera.

Orchidaceae in Puglia (Italy): Consistency, Distribution, and Conservation.

A study of the distribution of orchid species in Puglia, based on an analysis of 2084 bibliographic reports from 2000 to 2022, was carried out with the aim of revising and updating the information on the consistency of the Orchidaceae family in Puglia, with a special focus on assessing threatened species occurring inside and outside protected areas. The work presents a checklist of the Orchidaceae taxa (genera, species, and subspecies) found in the region, including observations on genera and species that present taxonomic challenges. A total of 113 taxa (i.e., species and subspecies), distributed across 16 genera, are listed in alphabetical order. The most representative genera were Ophrys (51 taxa), Serapias (15 taxa), and Epipactis (11 taxa). Additionally, 49 taxa (43.4%) were found to be endemic to Italy, with 21 of these, mostly belonging to the Ophrys genus, being exclusive to Puglia. Our study notes two different trends of distribution: a predominantly coastal distribution for orchid records located in southern Puglia (the Salento peninsula) and a more widespread distribution for the other provinces. Our study also shows that the greatest number of records locate orchids in protected areas with a positive correlation between their presence and habitats cited in Directive 92/43/EEC.

Comparative chromosome studies in species of subtribe Orchidinae (Orchidaceae).

In our study, FISH mapping using 18S-5.8S-25S rDNA and 5S rDNA sequences was performed for the first time on Ophrystenthredinifera Willdenow, 1805, Serapiasvomeracea (Burman f., 1770) Briquet, 1910 and Himantoglossumhircinum (Linnaeus, 1753) Sprengel, 1826. A detailed study was also performed on O.tenthredinifera using Giemsa-staining, silver-staining, CMA fluorescence banding and fluorescence in situ hybridisation (FISH) with rDNA probes. We analysed two subspecies, i.e. O.tenthrediniferasubsp.neglecta (Parlatore, 1860) E.G. Camus, 1908 and O.tenthrediniferasubsp.grandiflora (Tenore, 1819) Kreutz, 2004 by the traditional Feulgen method and constructed the karyotype. The cytotaxonomic implications for both taxa are also discussed. In Himantoglossumhircinum, FISH and silver staining highlighted differences in the number of two rDNA families (35S and 5S) with respect to Barliarobertiana (Loiseleur-Deslongchamps, 1807) Greuter, 1967. In addition, fluorescence in situ hybridisation was also applied to diploid (2n = 2x = 36) and triploid (2n = 3x = 54) Anacamptismorio (Linnaeus, 1753) R.M. Bateman, Pridgeon et M.W. Chase, 1997. As far as we are aware, this is the first case of autotriploidy observed in A.morio.

Karyomorphometry on three polyploid species of Arum L. (Araceae, Aroideae).

In this study three polyploid Arum Linnaeus, 1753 species from Southern Italy were chromosomally investigated. Arum italicum Miller, 1768 was found to have 2n = 84 chromosomes and a karyotype composed of numerous asymmetric chromosomes. Arum maculatum Linnaeus, 1753 and Arum apulum (Carano) P. C. Boyce, 1993 were found to have 2n = 56 chromosomes. In the examined taxa some chromosome pairs were characterized by the presence of weakly coloured Feulgen-stained segments. The karyotype morphology of Arum italicum was found to be similar to that of Arum maculatum, but the more asymmetrical karyotype and numerous weakly coloured Feulgen-stained segments observed in the former suggest the existence of more extensive rearrangements. In contrast, Arum apulum was observed to have a symmetrical karyotype. The A1, A2 and SYi karyotype asymmetry indices are presented. The relationships between these taxa in terms of karyotype morphology and evolution are discussed.