FUNGI AND LICHENS IN THE BALTICS AND BEYOND XVIII ...

Needle extracts did not inhibit the growth of L. seditiosum. Therefore only bark
extracts were used in further experiments. Bark extracts prepared with different extraction
methods were used in present study. Ethanol-based bark extracts in higher concentrations had
stimulating effect on fungal growth but in low concentrations (0.1%) inhibited fungal growth.
Bark extract on the base of sodium hydroxide in 1% and 1.5% concentrations inhibited
mycelial growth. In addition, L. seditiosum isolates of different origins were tested on media
with addition of different extracts.
Interesting aspect was that fungal culture growth forms differed according to extract
added to media – on some extracts fungi formed mycelia mostly on media surface but on
some extracts fungi grew deep into the agar media.
NEW PATHOGENS ON LEAVES OF Alnus spp. IN LITHUANIA
S. MARKOVSKAJA
Institute of Botany, Nature Research Center, Laboratory of Mycology, Žaliųjų Ežerų Str. 49,
LT-08406 Vilnius, Lithuania
E-mail: svetlana.markovskaja@botanika.lt
In the mid-1990ies an epidemic of foliar rust affecting alder trees began in Europe.
The agent was identified as new host-alternating rust fungus Melampsoridium hiratsukanum
S. Ito ex Hirats., which for the first time was recorded in Baltic region by the end of 1990ies.
In Lithuania it also appeared around 1998 (according to the first collected specimen preserved
in BILAS herbarium). This Asian rust fungus probably was introduced to Europe with its first
(aecial) host plants Larix spp. and have been rapidly spreading in Europe by the
urediniospores on their second (telial) host plants Alnus spp. Apparently it is a relatively
aggressive pathogen especially for grey alder, which may also infect leaves of more resistant
black alder. During present study we found that M. hiratsukanum is already widely spread in
our country on Alnus incana and started to appear on Alnus glutinosa. In 2010 we found M.
hiratsukanum at the edge of the great cormorant colony (Curonian Spit) strongly affecting
leaves of both A. incana and A. glutinosa. Other pathogen, an eriophyid mite Acalitus
brevitarsus Fockeu (by symptoms resembling rust fungi) was found on Alnus glutinosa leaves
together with the fungus. In the other parts of Curonian Spit and continental Lithuania these
pathogens – the rust fungus and the mite are never found together, this only exception was
recorded in the forest affected by cormorants. The reason for this is that Melampsoridium
hiratsukanum mainly infects leaves of Alnus incana, meantime Acalitus brevitarsus affects
only leaves of A. glutinosa. Evidently, the forest affected by cormorant activity became more
susceptible to pathogens and invasive species.
Acknowledgements. This research was funded by a grant No LEK -23/2010 from the
Research Council of Lithuania.