sdu faculty of forestry journal special edition 2009 - Orman Fakültesi

SDU Faculty of Forestry Journal
Serial: A, Number: Special Issue, Year: 2009, ISSN: 1302-7085, Page: 29-32
THE OCCURRENCE OF MICROCONIDIA ON Gremmeniella abietina
(LAGERB.) MORELET
ABSTRACT
Antti UOTILA 1*
1 Hyytiälä Forestry Field Station, University of Helsinki, Finland
*antti.uotila@helsinki.fi
The Gremmeniella abietina microconidia were observed during 1981-2002 in
numerous finnish specimen and pure cultures of the fungus. Microconidia existed in
type A and B on Gremmeniella abietina. Microconidia were found in pycnidia and
apothecia. Grey microconidial mass was produced also in pure cultures. Size of
microconidium was 3-6 µm X 1 µm. The germination was not observed. The attempts
to produce apothecia with the help of microconidia in lab failed.
1. INTRODUCTION
Finn and Helka Roll-Hansen first reported microconidia in 1973. They found
microconidia in pycnidia in Norwegian samples of G. abietina. The colour of
microconidial mass was grey instead of pink as conidial mass. Bergdahl and
Tsajkowski (1982) reported microconidia in North America. According to them
microconidia rarely germinate. Microconidia are also described in taxonomical
work of Petrini et al., 1989, when microconidia were found on different races or
types of G. abietina. My purpose was to check the occurrence of microconidia
in two types of G. abietina existing in Finland. In addition apothecia were tried
to produce by transferring microconidia.
2. MATERIAL AND METHODS
These results based on notes which I have done on different experiments and
cultures of numerous G. abietina isolates during 1981-2002. Hundreds of
microscope slides were examined. They were done from natural pycnidia or
apothecia and also from pure cultures in laboratory. The types of G. abietina
were determined by conidial septa and disease symptoms. Later the types were
confirmed with fatty acid (Müller & Uotila, 1997) or RAMS method (Hantula
&Müller, 1997; Uotila et al., 2000). After determining mating alleles of G.
abietina (Uotila, 1992) the pairing experiment with microconidia was done. G.
abietina has two mating alleles, mat 1 and mat 2. The microconidia from the
monospore culture were transferred to culture having different mating allele.
The cultures were grown in erlenmeyer bottles on barley groats +pine needles
medium.
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