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 theMansfeld 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 northwestedge 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. Between1956, were the first scientific study took place, and the mid of the 1970s the population at the locusclassicus decreased rapidly due to increasing bush encroachment of the dry- and semi-dry meadowsmainly caused by the abandonment of sheep grazing. Since 1979 considerable efforts were undertakento stabilize the species by in-situ conservation and accompanying habitat management measures. Intotal, 575 plants of Marrubium peregrinum were grown up and planted at the sites of the three naturalpopulations, at new established protection sites in their surroundings, and at the churchyard of Erdebornbetween 1979 and 2002. Despite extensive nurse three of these protection sites had to abandon after fourand five years, respectively, and one more after 13 years. Nevertheless, the total population increasedfrom 24 plants in the year 1979 to 59 in the year 2009. So, regarding only the number of individuals, thesituation of 1956 is achieved.The described bastard (M. x paniculatum) of M. peregrinum and M. vulgare was detectable neither byAFLP analysis nor by sequence analysis of the internal transcribed spacer (ITS) II. The ITS II containsnine variable positions. Seven of them separate Marrubium vulgare and M. peregrinum. Plants with themorphological characters of M. peregrinum and M. x paniculatum are not distinguishable by their ITSII-sequences.The genetic structure and the genetic variability of the seven central German populations and of twoAustrian populations was analysed by amplified fragment length polymorphism (AFLP). Genetic structureof the seven central German populations does not reflect their geographical structure. Due to there-plantations we can only detect three genetic populations which can be assumed as subpopulations ofone Marrubium peregrinum metapopulation in the Mansfeld Lake district.The large genetic distances between the Austrian and the central German populations indicate a longtermisolation from the latter to the main area of the species. Nevertheless, our molecular data don´t allowconclusions 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, vegetationchange, historical analysis