Acta Botanica Croatica, Vol. 43 No. 1, 1984.
Izlaganje sa skupa
The Genus Avenula (Dumort.) Dumort., Poaceae, on the Balkan Peninsula
Wilhelm Sauer
; Njemačka
Sažetak
Karyological data show a very differentiated pattern of evolution for wild oats of the Balkan Peninsula and adjacent territories
1. The genomes of the species discussed far Avenula and Helictotrichon suggest identical trends of their evolution. Already on the diploid level, mor or less asymmetric karyotypes have evolved probably from more or less original and symmetrical ones. — A similar differentiation has happened within the annual oats (Avena) also on the diploid level (genome B, C, D), but on the basis of already more advanced karyotypes, such as genome A, which could also be found in perennial oats (A. com- pressa). — Finally in several regions high polyploid groups of (perennial) oats have evolved parallelly from diploid and/or lower polyploid species (s. figs. 4 and 5).
2. The diploid species (2n = 14) are represented by Avenula pubes- cens, A. versicolor, A. compressa, Helictotrichon parlatorei, H. petzense, and H. convolutum. — A. blavii and A. aetolica are tetraploid (2n = 28). — For the first time a decaploid chromosome number (2n = ± 70) has been found in A. cycladum. — High polyploid chromosome numbers characterize A. adsurgens (18x: 2n = ± 126), and A. praeusta (18x and 20x — 22x: ± 140 — ± 154).
3. Within the diploid species of the perennial oats well defined groups of species can be distinguished, which are present in nearly all regions of the Balkan Peninsula: A wide distribution in the lowlands of temperate Europe and West-Asia is characteristic of Avenula pubes- cens, while A. compressa is found in the regions around the western part of the Black Sea. To the south(east) both species ascend more and more into the mountains. — Avenula versicolor and Helictotrichon parlatorei represent species of the European high mountains. With respect to their ecological adaptation to alpine meadows or to screes of the Limestone Alps their areas are characterized by a marked disjunction. — Endemic H. petzense occupies a very small area in the eastern Kara- wanken and in the Steiner Alpen. — H. convolutum represents a species of rocky and sandy habitats of the eumediterranean region from Sicily to Greece (and, probably, of Turkey).
4. The tetraploid species Avenula blavii and A. aetolica are characterized as endemic species of the central and/or southern mountains of the Balkan Peninsula.
5. High polyploid species have often been wrongly interpreted. They are centered on three well circumscribed regions: Avenula cycladum s.l. represents a group of microspecies in the South Aegean Sea, with a highly splitted area. A. adsurgens is a typical species of continental regions from the eastern East-Alps to Transylvania, but lacking in the Hungarian Lowlands. — According to our present knowledge, probably, A. praeusta represents a species of alpine meadows of the eastern South- Alps.
6. Very often Avenula pratensis and A. planiculmis have been confused with other species. They seem to be absent from the Balkan Peninsula.
Ključne riječi
Hrčak ID:
159042
URI
Datum izdavanja:
31.12.1984.
Posjeta: 998 *