Appearance of senescent sectors in the ageing vegetative thallus of several basidiomycetous fungi held in pure culture
✍ Scribed by G. Gramss
- Publisher
- John Wiley and Sons
- Year
- 1991
- Tongue
- English
- Weight
- 505 KB
- Volume
- 31
- Category
- Article
- ISSN
- 0233-111X
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✦ Synopsis
The initially juvenile stock cultures of basidiomycetous wood-decay fungi lose most of their physiological performances during long-term storage in axenic culture. In order to link the rapidity of this debilitation or senescence process with the properties of the fungal genome, both a juvenile strain of Bjerkandera adusta (Bjerad 2S3) and a pre-aged strain of Hypholoma sublateritium (Ns 1) were transferred to 7 identical round flasks with a liquid still culture medium and maintained at 23 "C. In a 6-month rhythm the disappearance of several juvenility marks among the 7 isogenic subcultures was recorded and compared with the vitality status of the 2 "C maintained reference strains. Within 26 to 30 months of observation, the 7 isogenic subcultures of Bjerad 2S3 as well as Ns 1 aged at a strikingly different speed. Both mycelial thalli segregated into coexisting sectors of progressive senescence and relative juvenility. The isogenic subcultures dominated by juvenile sectors displayed dramatically longer life spans than did the subcultures dominated by the senescent mycelial sectors. This means that initially isogenic parts of a mycelial thallus have a strikingly different life expectancy. In the slow-ageing subcultures of Ns I, neither the senescent nor the juvenile sector were able to overgrow and infect the colony of their coexisting conterpart. The preconditions are discussed that could possibly prevent the spread of the carriers of senescence into the juvenile mycelial parts.