Die Situation des Wander-Andorns (Marrubium peregrinum L.) im Mansfelder Seengebiet – ein Beitrag zur Bedeutung von In-situ-Erhaltungskulturen

Abstract

Baumbach, H.; Lühne, E.; Volkmann, H. K. M.: On the situation of Marrubium peregrinum L. in the
Mansfeld Lake district – a contribution to the importance of in-situ plant conservation. – Hercynia N. F.
43 (2010): 85 –118.
One of the rarest and critically endangered plants of the German flora is Marrubium peregrinum L. (Lamiaceae),
the horehound. It is confined to dry loam slopes near the village Wormsleben at the northwest
edge of the lake Süßer See and the churchyard of the village Erdeborn (federal state of Saxony-Anhalt)
in the central German dry region. M. peregrinum was first mentioned there by V. Cordus in 1542. Between
1956, were the first scientific study took place, and the mid of the 1970s the population at the locus
classicus decreased rapidly due to increasing bush encroachment of the dry- and semi-dry meadows
mainly caused by the abandonment of sheep grazing. Since 1979 considerable efforts were undertaken
to stabilize the species by in-situ conservation and accompanying habitat management measures. In
total, 575 plants of Marrubium peregrinum were grown up and planted at the sites of the three natural
populations, at new established protection sites in their surroundings, and at the churchyard of Erdeborn
between 1979 and 2002. Despite extensive nurse three of these protection sites had to abandon after four
and five years, respectively, and one more after 13 years. Nevertheless, the total population increased
from 24 plants in the year 1979 to 59 in the year 2009. So, regarding only the number of individuals, the
situation of 1956 is achieved.
The described bastard (M. x paniculatum) of M. peregrinum and M. vulgare was detectable neither by
AFLP analysis nor by sequence analysis of the internal transcribed spacer (ITS) II. The ITS II contains
nine variable positions. Seven of them separate Marrubium vulgare and M. peregrinum. Plants with the
morphological characters of M. peregrinum and M. x paniculatum are not distinguishable by their ITS
II-sequences.
The genetic structure and the genetic variability of the seven central German populations and of two
Austrian populations was analysed by amplified fragment length polymorphism (AFLP). Genetic structure
of the seven central German populations does not reflect their geographical structure. Due to the
re-plantations we can only detect three genetic populations which can be assumed as subpopulations of
one Marrubium peregrinum metapopulation in the Mansfeld Lake district.
The large genetic distances between the Austrian and the central German populations indicate a longterm
isolation from the latter to the main area of the species. Nevertheless, our molecular data don´t allow
conclusions at which time M. peregrinum was dispersed or migrated into the central German dry region.
Key words: Marrubium peregrinum, endangered plant species, in-situ plant conservation, AFLP, vegetation
change, historical analysis