Category Archives: Volume 28 1988

Correlation between mycorrhizae and the growth of Pinus sylvestris in ploughed sites in northern Finland

Authors: Väre, Henry
Journal: Karstenia, Volume 28 (1988), Issue 1, pages 31-33.
Doi: https://doi.org/10.29203/ka.1988.259
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Abstract:  Scots pine saplings were examined in some clear-cut sites in northern Finland. The length of the saplings, the number of annual needle crops and the mycorrhizal infection percentage were recorded in saplings grown in ploughed and unploughed sites in order to reveal 1) the effect of ploughing on mycorrhiza formation and 2) the effect of possible disturbances in mycorrhiza formation on the growth of saplings. The mycorrhizal infection percentage was significantly lower in the double humus layer at ploughed sites than in the undisturbed humus layer at unploughed sites. The mycorrhizal infection percentage showed a significant positive correlation with the length of the saplings and the number of annual needle crops. In injured saplings, in which the length and number of annual needle crops were lowest, mycorrhiza formation was also poorest.

Comparison of radial growth rate of mycorrhizal fungi isolated from 43 species of northern orchids

Authors: Lindén, Ben R.
Journal: Karstenia, Volume 28 (1988), Issue 1, pages 19-25.
Doi: https://doi.org/10.29203/ka.1988.256
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Abstract:  The investigation is part of a study devoted to the propagation of Scandinavian orchids. Endophytes from the roots of 43 orchid populations and, for comparison, from Moneses uniflora and four saprophytic fungi were isolated and the growth rates measured. The rates recorded ranged from 1.1 to 9.6 mm per 24 hours. The growth-retarding effect of tannin was also investigated. The response varied from total inhibition to no retarding effect. It is suggested that the differences in growth rates and response to retardants, which both seem to be dependent on the host taxonomy and ecology, can be of use in identifying the mycorrhizal endophytes.
Instead of the conventional isolating methods involving prolonged disinfection, the orchid roots were merely washed in soapy water, subjected to a high-pressure water jet, cut into segments and plated on plain water-agar medium. Contaminant-free cultures were easily achieved in this manner. Water-agar was also used for maintenance of cultures and growth rate observations.

Endomycorrhizal fungus in chlorophyll-free and green forms of the terrestrial orchid Epipactis helleborina

Authors: Salmia, Aulikki
Journal: Karstenia, Volume 28 (1988), Issue 1, pages 1-18.
Doi: https://doi.org/10.29203/ka.1988.255
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Abstract: A brown, slowly growing unidentified fungus was isolated from nine (chlorophyll-free, yellowish-green and green) individuals of Epipactis helleborine (L.) Cranz collected from Finland. The brown fungus appeared regularly from sterilized root segments, and four isolates were obtained from hyphal coils in cortical cells of both green and white individuals. The results indicate that the same endophyte inhabited white and green plants of E. helleborine, and that the brown fungus can be considered to be the endophyte of this species, though this has not yet been confirmed with symbiotic tests. The effect of different surface-sterilizing agents on the appearance of the brown fungus from root pieces was investigated. The most suitable sterilization chemical proved to be 0.1% mercuric chloride in 50% ethanol. The morphology and some characteristics of the fungus are described. The growth pattern and microscopic chracateristics of the brown endophyte differ from those of the well-known orchid fungi. No teleomorph could be obtained in culture.