Dimitris Tzanoudakis

Changes in non-structural carbohydrate composition during bulbing in sweet and high-solid onions in field experiments.

The composition of non-structural carbohydrate (NSC) content of predominantly long-day onion germplasm has been assessed over several years and in a bi-location trial. It was observed that genetic rather than environmental factors determined the NSC composition of onion bulbs. Glucose was the NSC component which was most closely correlated with genotype. Fructose was the only NSC component that was significantly affected by environment. Sucrose and 1-kestose (DP3 fructans) were not correlated to a large extent to the other NSC components, indicating their transient role in the fructan metabolism. Strong negative correlations were observed between reducing sugars (i.e. fructose and glucose) and dry matter content (DM). Furthermore, it was shown that accessions differed significantly in their fructan accumulation pattern; high DM accessions showed accumulation of fructans over the whole bulbing period, whereas, low DM accessions quickly reached a plateau. Implications for the breeding of high quality onions are discussed.

A floristic investigation of the islet groups Arki and Lipsi (East Aegean area, Greece)

Arki and Lipsi are two islet groups situated in the NNW part of the prefecture of Dodecannisos (E Aegean area, Greece), which consist of 37 islets in total, of which three (Lipsos, Arki and Marathi) are permanently inhabited. From the area studied 557 taxa of Tracheophytes have been registered and the chorological and life-form analyses of the flora have shown the predominance of the Mediterranean elements and the therophytes, respectively, confirming the Mediterranean character of the flora. However, significant fluctuations have been observed regarding the representation of both, chorological and life-form types, from islet to islet. A comparison of the individual flora of the 37 islets studied, revealed very low floristic similarity even between neighbouring islets (β-diversity). Not one of the taxa registered was present on all 37 islets; yet, 199 taxa were present on only one islet. Eight of the taxa registered in the studied area fall under a protection status according to international lists. The floristic data were statistically evaluated with respect to species-area relationship and other geographical factors such as altitude, minimum distance from a larger inhabited island and sea depth.

Contribution to the study of the Greek flora: Flora and vegetation of the E Aegean islands Agathonisi and Pharmakonisi

Abstract Panitsa, M. & Tzanoudakis, D.: Contribution to the study of the Greek flora: Flora and vegetation of the E Aegean islands Agathonisi and Pharmakonisi. — Willdenowia 28: 95–116. 1998. — ISSN 0511-9618. The flora and vegetation of the north-easternmost islands of the prefecture of Dodekanisos, Agathonisi and Pharmakonisi, which remained floristically almost unexplored until recently, have been investigated. Included are also the flora and vegetation of the seven islets around Agathonisi. Altogether, 402 species and infraspecific taxa of higher plants belonging to 131 genera and 52 families have been found. The analysis of the flora and the classification of the taxa into three main chorological units and five life form types shows that the Mediterranean elements and the therophytes predominate. A comparison of the individual floras of the two islands and seven islets revealed very low values of Sørensens similarity coefficient, indicating a remarkable floristic independence. This floristic independence is also expressed by the fact that the nine islands and islets have not one taxon in common, whereas 130 taxa occur only on one island or islet each. Three vegetation zones (littoral, epilittoral and interior) are distinguished and described. The vegetation physiognomy differs from islet to islet due to different dominant species. Human activities such as agriculture, grazing, fires, etc. likewise affect the local floristic composition and vegetation physiognomy.

Contribution to the study of the Greek flora: Flora and vegetation of the Enousses (Oinousses) islands (E. Aegean area)

Summary Enousses is an islets group situated eastwards of Chios island (E. Aegean, Greece), which remained quite unexplored floristically. Based on our herborizations, 270 taxa belonging to 51 families and 204 genera of spermatophytes are listed for the flora of this area. The flora of the area is analysed and the plant species recognized are classified into 9 chorological groups and 5 life form types. The results of this analysis confirm the Mediterranean character of the flora since the Mediterranean elements and the therophytes are predominant in the area. The vegetation of all islets is characterized by the dominance of phryganic communities, and the three “vegetation zones” distinguished (littoral, sublittoral and interior ones) are described. Geological history, geography, microecological differences, random events and human activities seem to be the most important factors related to the diversity of the flora and vegetation observed in our area. Special attention has been given to human interference, since in the bigger islets of the group -which are used for agriculture, grazing etc. - high percentages of Therophytes and Leguminous species have been observed (indexes of disturbance). On the contrary, in the smaller ones, which are not affected by human activities (i.e. Vatopoula), these indexes show deviate values. For this reason, the importance of the small islets ecosystems in floristic and ecological studies in the Aegean area is pointed out.

The cytogeographical distribution pattern ofAllium (Alliaceae) in the Greek Peninsula and Islands

Greece is considered as a secondary centre of evolution for the genusAllium since it possesses about 50% of the species known from the whole Flora Europaea area. In the present investigation 44 GreekAllium spp. have been studied and new chromosome counts are reported from 40 populations and 17 species. The distribution of the different cytotypes (x = 7, x = 8, x = 11 and 2n = 2x, 3x, 4x, 5x, 6x, 7x) in Greece is discussed. From the four phytogeographical subdivisions recognized, South continental Greece shows the greatest species and karyotype diversity. This phenomenon is probably due to the geographical position and to the geological history of this area which has received species and populations from different directions. Subsequently, hybridization apparently has been of evolutionary importance.

Contribution to the Study of the Greek Insular Flora: Antikythera and the Islets Around Kythera

The Kythera-Antikythera island chain is one of the most interesting areas of Greece, from a floristic and biogeographical point of view. It is considered as the remnant of an old landbridge which connected Western Crete with Southern Peloponnisos. The whole area is dominated by limestone cliffs, a biotope where many Greek and Aegean floristic elements find refuge. The island chain consists of 3 main, inhabited islands, Elafonissos, Kythera and Antikythera, and a number of small and uninhabited islets (Fig. 1). Elafonissos and Kythera are considered floristically well known (see Tzanoudakis & Panitsa 1994 for references), so we focused our efforts on the floristic exploration of the islets, which remained quite unexplored, and also to Antikythera which is the most remote and isolated among the larger ones. The latter is included in “Flora Kytherea” of Greuter and Rechinger (1967), but the floristic information are based on collections made by the authors and Prof. Phitos, during the same season (first half of May) of the same year (1964).

ALLIUM CHALKII (LILIACEAE), A NEW SPECIES FROM THE EASTERN AEGEAN ISLAND OF CHALKI (GREECE)

ABSTRACT Allium chalkii is described as a species new to science. Until now, this rare species is known only from the small island of Chalki (Dodekannisos, Greece) and it shows some relationships with A. cuponi, A. sipyleum, and A. lojaconoi. The diploid chromosome number of A. chalkii is 2n = 16, and the chromosome morphology of the complement is described.

A new polyploidScilla (Liliaceae) from the Cretan area (Greece)

Scilla talosiiTzanoudakis etKypriotakis from the islet of Dia is described as a new species. It is an autumn-flowering taxon related toScilla autumnalis L. andS. obtusifoliaPoiret but distinct morphologically and cytologically from both these taxa.S. talosii is polyploid with 2n=ca. 150 chromosomes.

Allium symiacum (Amaryllidaceae), a new species from Symi Island (SE Aegean, Greece)

Abstract: Allium symiacum Galanos & Tzanoud., from the island of Symi (SE Aegean, Greece), is described as a species new to science. It is an autumn-flowering, single-island endemic species of A. sect. Codonoprasum (Amaryllidaceae) and is classified as Critically Endangered according to IUCN Red List categories and criteria. Considering the morphological and karyological characters of the new species, its possible relationships to other autumnal species of A. sect. Codonoprasum distributed in the E Mediterranean area are discussed. Citation: Galanos Ch. J. & Tzanoudakis D. 2017: Allium symiacum (Amaryllidaceae), a new species from Symi Island (SE Aegean, Greece). — Willdenowia 47: 107–113. doi: https://doi.org/10.3372/wi.47.47202 Version of record first published online on 17 May 2017 ahead of inclusion in August 2017 issue.