cytat:vital taxonomy: The term was created because of the universal experience in most groups of fungi that living cells contain an extraordinarily higher amount of taxonomically relevant micromorphological information. Vital taxonomy requires no special or expensive equipment. It means to base taxonomic and monographic work on characters of the living cells studied with the light-microscope at magnifications of 1500-2000x using oil immersion, bright field optics, and water as mounting medium. Standard microscopes with good objectives (100x apo?chromates) and cheap 15x oculars provide excellent results. Herbarium material is only used for detailed study if a species is not available from enough fresh finds, or for re-description of type material. Since many species are only found more or less accidentally even if their ecology is known in detail, vital taxonomy means to work simultaneously on several taxonomic groups in order to take the chance for vital studies on rare species, so as to have studied as much species as possible in the living state. Therefore vital monographies take longer to be finished but contain a huge amount of exact information, and the worker has simultaneously gained knowledge in a wide range of other groups which fastens appearance of the next monograph. The mere use of -> fresh collections is no guarantee for vital taxonomy because careless transport and preparation, and the use of -> lethal mountants provokes the cells to die. The vital taxonomist must perfectly know how to distinguish between living and dead cells, since fresh fruit-bodies often contain a considerable amount of dead cells already in the field, depending on its -> senescence. - The term -> “vital” means in English also something like “prominent”, an attribute which indeed applies to the vital taxonomy as well. -> herbarium taxonomy, -> vital efficiency
cytat:vital efficiency: Workers believe they have no time for microscopic study after having collected fresh living ascomycetes. They have a lot of other duties, but most do not know that vital efficiency brings wisdom. The period of time investigated in a living specimen carries manyfold fruit. There is no need to study collections at the same day. In the refrigerator at 5-10°C fresh samples stay alive and mature for several days or even one week. Mailing samples in tight boxes is possible even over the great ocean, if the weather is not too hot. The large group of -> xerotolerant ascomycetes (most pyenomycetes and over 50% of the inoperculate discomycetes) survive many weeks, months, or even years in the herbarium, therefore samples from semideserts can often be revived and studied in full vitality 2-3 years after collection!
cytat:tap water (H2O) (of medium hardness): The only -> mounting medium to study living cells under the oil immersion microscope. Rain water or very hard water are of equal use. “Physiological” media with a concentration of 0.85% NaCl do not reflect the natural exposure to rain water, and cause slight shrinkage to the cells by water loss. Additions of -> basic dyes in low concentration are allowed but support the death of the cells within a limited time. Disadvantages of water are: (1) rather rapid -> evaporation under the cover slip, (2) movement of freely -> floating spores.
cytat:Brilliant cresyl blue (CRB): 0.1-1g in 100g tap water. Used for -> vital staining of cell contents, and for staining of gels on the cell wall surface. CRB is a stain to prove vitality of individual cells, and CRB is a pH-indicator: the colour is (greenish-)blue at high pH, (reddish-)violet at low pH. Living cells are required for staining cell contents: -> VBs are stained turquoise-blue, -> cystoblasts blue; normal vacuoles stain homogenously violet-blue (e.g. the large vacuole of mature asci), but frequently the dye precipitates within the vacuole to form deep blue, globose -> metachromatic bodies (MCs). Extracellular material stains the same way in both living and dead condition: gel stains violet, and hyaline resinous exudate mostly turquoise-blue. -> Toluidin blue gives the same results.
cytat:evaporation: Evaporation of water under the cover slip must repeatedly be compensated by small drops when studying a preparation longer than about 10-15 minutes. Excessive water loss causes compression of soft fungal fragments which makes the individual elements very difficult to study. Addition of a small drop of water to the edge of the cover slip removes the problem. Mounting media like MLZ or CB do not evaporate significantly during several hours but immediately kill the cells and prohibit -> vital taxonomy.
cytat:herbarium taxonomy is the classical method for fungal classification. It is based on dry dead material, and for reasons of compatible comparison fresh living collections are first killed by -> lethal mounting media. The great advantage of herbarium taxonomy is convenience: samples of the group under monographic study can be ordered from herbaria and specimens of a single species can simultaneously be examined one after the other. The results of -> vital taxonomy are often very different because of much more available characters with a much higher consistency. One of many examples of -> vital characters is the -> spore body in Orbiliales: this very conspicuous organelle (but visible only in living spores) is the best character to (1) recognize the order, and (2) delimit between genera, infrageneric groups, and species. 200 species can be recognized so far in the Orbiliales based on vital taxonomy; with the herbarium method less than about 50 species can be distinguished. -> vital efficiency