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FP5

GIANT ALIEN Résumé de rapport

Project ID: EVK2-CT-2001-00128
Financé au titre de: FP5-EESD
Pays: United Kingdom

Clarification of the genotypes and subspecies in H mantegazzianum populations in Europe

187 samples were analysed of 12 Heracleum species from 72 populations collected in 15 countries in Europe and in 3 countries in the Caucasus region including:
(i) invasive species: H. mantegazzianum, H. sosnowskyi and H. persicum;
(ii) native species: H. sphondylium and H. sibiricum;
(iii) other species: H. antasiaticum, H. leskovii, H. pastinacifolium, H. transcaucasicum, H. ponticum, H. trachyloma (all from Caucasus) and H. stevenii.

To assess genetic similarity and for rooting of the dendrogram out-group species (Ferulago and Daucus) were added. The nine primer combinations produced a total of 630 AFLP fragments, 95% of them were polymorphic. To assess the genetic relationships between species/populations an unweighted pair group mean analysis (UPGMA) and principal Principal coordinates analysis (PCO) were performed. Results revealed great genetic similarity between the three species of Heracleum that are invasive in Europe and also some other tall Heracleum species from the Caucasus. The out-group species (Daucus and Ferulago) were only about 17-20% similar to Heracleum species.
The target invasive species were also clearly separated from
(i) H. sphondylium, H. sibiricum and H. ponticum, and
(ii) H. antasiaticum and H. leskovii.

Heracleum mantegazzianum samples from both the Caucasus and Europe were genetically very close (similarity about 80%). Samples of Heracleum sosnowskyi formed two clusters - one including samples from the invaded range (Europe) and the other grouping samples from the native range (Armenia, Transcaucasia). Such division indicates that this species in Europe either comes from other parts of the greater Caucasus, or that it was subject to some modifications prior to its introduction to Europe. Russian records suggest that seeds of H. sosnowskyi that were used in plant breeding programs in NW Russia (Murmansk and Leningrad) originated from Republic of Kabardino-Balkaria (Russian Caucasus).

Samples of Heracleum persicum from Nordic countries clustered with some tall Heracleum species from the Caucasus (H. trachyloma H. pastinacifolium, H. transcaucasicum). As reference samples from native range (Iran and Turkey) of H. persicum were not obtained, we could not confirm the conspecificity of the Nordic plants with the Iranian H. persicum. Some interesting results were revealed by this analysis. Very close genetic relationship between Heracleum sp. samples from Buckingham and Kensington Palace Gardens (London) and H. persicum from Norway confirms hypothesis that the H. persicum was brought to north Norway in the early 19th century by English gardeners. Samples from two populations of H. persicum collected in Denmark formed a separate cluster apart from samples from Norway and Finland, suggesting that multiple introductions are responsible for invasion of H. persicum to Nordic countries.

This analysis also pointed to a possible identification problem as samples collected in two parks in Latvia and labelled as H. mantegazzianum showed great genetic similarity to H. persicum and the above mentioned related species. It is unlikely that these plants could be H. mantegazzianum and are either of hybrid origin or are in fact H. persicum or other close species. Due to unresolved taxonomy in H. persicum group more work has to be undertaken to determine the status of these plants.

Contact

Heddwyn JONES, (Senior Lecturer)
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