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Stott, K. and A. Broderick. 1996. Response of
Australian strains of the mushroom Lepista nuda to temperature and
substrate. p. 476-479. In: J. Janick (ed.), Progress in new crops. ASHS
Press, Arlington, VA.
Response of Australian Strains of the Mushroom Lepista nuda to
Temperature and Substrate
Karen Stott* and Andrew Broderick
- METHODOLOGY
- Isolates
- Temperature
- Substrate and Cold Shock
- RESULTS
- Isolates
- Temperature
- Substrate and Cold Shock
- CONCLUSION
- REFERENCES
- Table 1
- Table 2
Taxonomic classification of macrofungi is constantly changing as new species
are discovered in North America, South Africa, and Australia. In Australia
there are probably 3000 to 5000 species, most of which have not been properly
described (Wood 1992). Improved techniques have enabled microscopic details to
be better researched and this has resulted in changes in taxonomic
classification.
The recent increase in consumption of wild mushrooms in many countries has
provided the impetus to explore new sources of edible mushrooms. In addition,
the wild harvesting of edible mushrooms must be curbed to ensure that the
environment and ecosystems where these mushrooms grow are not destroyed.
Mycologists need to explore new mushroom sources (Purkayastha and Chandra 1985)
and develop cultivation techniques.
Worldwide there are 200 edible fungi of which only 25 species are widely
accepted as human food and are cultivated (Hashioka and Arita 1978; Chang 1981;
Pathak 1986). Fungi other than Agaricus bisporus represent about 30% of
world production (Olivier 1991). The influx of migrants with a European
heritage into Australia has created a demand for edible mushrooms produced
locally. Amongst the gilled fungi, there are a number of edible species in the
Agaricaceae, Bolbitiaceae, Lepiotaceae, and Tricholomataceae.
The fungus Lepista nuda, Tricholomataceae (syn: Tricholoma nudum,
Rhodopaxillus nudus, Clitocybe nuda) is found in Europe, the Americas, and
Australia. It has an international reputation as an excellent edible species
and the combination of its lilac color, solid fleshy structure, good shelf
life, flavor, and aroma makes the development of commercial cultivation
techniques highly desirable. Developing techniques for commercial cultivation
requires a detailed understanding of environmental and nutritional parameters
which optimise vegetative growth and induce fruiting bodies.
The development of an appropriate substrate requires the chemical, physical,
and biological conditioning of composted matter. This creates an environment
selective for a particular species that is critical for fruit body production.
Factors to be considered in the substrate are microbial activity, physical
characteristics, pH, chemical components, aeration, water content, substrate
composition, and extent of composting undergone by the substrate. Some species
require the application of a casing layer of peat or soil to enhance yield and
quality. Casing assists the induction of fruit bodies, but how this occurs is
largely unknown. It is thought that casing provides a high water holding layer
for hyphae, entraps volatiles released by compost, has a different mycoflora to
the substrate, and physically supports the growing fruit body. The physical
and chemical characteristics, optimal depth and number of applications for a
given casing material can be different for each species. Temperature, light,
O2 , CO2 , watering and care must be managed to encourage fruit body formation.
Previous studies on substrate requirements of European Lepista
(Vaandrager and Visscher 1981) indicate that fruit body production is enhanced
by the addition of 10% uncomposted straw to commercial Agaricus compost.
Guinberteau et al. (1989) and Brian et al. (1979) reported that a cold shock is
essential for the formation of fruit bodies of L. nuda and temperatures
of 8° to 15°C have been found to be effective. However Australian
isolates (Young 1994) have been found under more variable environmental and
substrate conditions than European isolates (Moser 1978, Breitenbach and
Kranzlin 1991).
The objective of the present study was to provide the Australian mushroom
industry with viable commercial cultivation techniques for Australian species
of Lepista. This paper describes Australian forms of L. nuda
isolated from the wild and examines the effect of temperature and substrate on
hyphal growth and fructification.
Under Australian conditions Lepista appears in the wild from April to
July. Isolates of Lepista were collected from various sites and voucher
documentation, identification, and isolation of strains was carried out. Most
isolates were confirmed as L. nuda and comparisons were undertaken with
French isolates of Lepista, provided by Dr. Guinberteau of Station de
Recherches sur les Champignons at Institut National de la Recherche
Agronomique, France (Table 1).
Optimum temperature for hyphal growth is a critical factor in obtaining rapid
colonisation of substrate and casing. Isolates were selected from locations
with different temperature and environmental characteristics to enable
comparison with French isolates. Growth response of four Australian (A1, A2,
A3, A4) and four French (F1, F2, F7, F8) isolates of L. nuda from warm
(A1, A2, F1, F2) and cool (A2, A3, F7, F8) climates were compared at different
temperatures to determine maximum and minimum temperatures for hyphal growth.
Isolates were grown on malt extract agar plus 2% yeast (MEAY) at 5°, 12°,
15°, 20°, 25° and 30°C. Radial growth of hyphae was measured on
day 8 in two directions and the average taken. Data was analysed by analysis
of variance.
Agaricus compost alone or suplemented with 10% uncomposted cereal straw
(w/w) was inoculated with Lepista at 2%-3% w/w. Trays were sealed and
placed at 25°C in a cabinet with temperature and light control. After 12
days substrate was cased with a 75% moisture content 50/50 mix of blond/dark
peat. After hyphae had grown through casing, lids were loosened to allow air
movement over substrate and cold shock of 12° or 15°C was applied to
replicates of both substrates.
The location and environment of selected isolates are shown in Table 1. Cool
climate isolates (4° to 25°C during growing season) were found in leaf
litter under Rhododendron, Cedrus deodara, Quercus suber or grass
(Poa pratensis). Basidiocarp very robust and fleshy, lilac to lilaceous
brown; pileus 75-132mm, lilaceous brown, shiny, convex to shallow convex with
age; stipe 50-78 mm x 25-33 mm.
Warm climate isolates (8° to 35°C during growing season) were found in
Kikuyu (Pennisetum) and Couch (Cynodon dactylon) grass in groups
or rings. Basidiocarp strong lilac to lilaceous brown; pileus 30-75 mm, strong
lilac, shallow convex with umbo at all stages; stipe 65 mm, bright lilac to deep
lilac or lilaceous brown.
The optimum temperature for Australian isolates was found to be higher than for
French isolates as was the minimum growth temperature. The growth rate of
Australian isolates is more than double the rate of French isolates at all
temperatures except 5°C (Table 2).
The addition of 10% uncomposted cereal straw encouraged hyphal growth, but
discouraged the initiation of fruiting bodies and was not beneficial to
Australian isolates. A cold shock of 12°C encouraged more hyphal
aggregations than 15°C. No fruit bodies were produced.
Australian isolates differ from overseas isolates morphologically in shape,
form, and size. They are found at different temperatures and in different
environments than European species. Whether they are new species or varieties
resulting from the Australian environment and habitat has yet to be determined.
The response of Australian isolates to temperature indicates that these
isolates have the capacity to colonise substrate more rapidly than French
isolates. This would be advantageous to commercial growers as cropping time
could be reduced.
The addition of 10% uncomposted straw to Agaricus compost had no
beneficial effect on the initiation of fruit bodies. Whether it would effect
quality or yield is unknown and further research into this area is
recommended.
Information from this study can provide the basis for the development of viable
commercial cultivation techniques for the exotic mushroom industry in
Australia. The differences in cultivation requirements and growth rates of
Australian and French strains indicates that a shorter production cycle than is
currently achieved with French isolates will be possible.
- Brian, C., J. Guinberteau, and L. Priobe. 1979. Obtention de fructification du
pied bleau, Rhodopaxilus nudus (Fr. ex Bul.) en conditions
artificielles. Academie d'Agriculture de France--extrait du proces-verbal de la
Seance du 14 Nov. 1979. 1365-1369.
- Brietenbach, J. and F. Kranzlin (eds.). 1991. Fungi of Switzerland, Vol. 3.
Boletes and Agarics 1st part. Edition Mykologia, Lucerne, Switzerland. p.
214-216.
- Chang, S.T. 1981. Mushrooms and mushroom science. Mushroom Newsletter for the
Tropics. 1:3.
- Guinberteau, J., J.M. Olivier, and M.R. Bordaberry. 1989. Données
récentes sur la culture des "pieds bleus" (Lepista sp.) PHM Revue
Horticole. 298 (June-July) 17-22.
- Hashioka, Y. and I. Arita. 1978. Mushroom Science X (part II). Naturalization
of several saprophytic mushrooms under rice-straw-culture. p. 127-135. In: J.
Delmas (ed.), Proc. Tenth Int. Congress on the Science and Cultivation of
Edible Fungi, France 1978.
- Moser, M. 1978. In: G. Kibby (ed.), Keys to Agarics and Boleti (Polyporales,
Boletales, Agaricales, Russulales. Roger Phillips. London. p.118.
- Olivier, J.M. 1991. Champignon comestibles et diversification. Mushroom Info.
4:20-21.
- Pathak, N.C. 1986. Utilization of natural mushrooms flora. p. 43-57. In: M.C.
- Nair and S. Balakrishnan (eds.), Beneficial fungi and their utilisation.
Symposium of the Mycological Society of India, held at the College of
Agriculture, Vellayani, Trivandum. Feb. 1984. Scientific Publishers, Jodhpur,
India.
- Purkayastha, R.P. and A. Chandra. 1985. Manual of Indian edible mushrooms.
Today and Tomorrow's Printers and Publishers, New Delhi.
- Vaandrager, M. and H.R. Visscher. 1981. Experiments on the cultivation of
Lepista nuda, the wood blewit. p. 749-760. In: N.G. Nair and A.D. Clift
(eds.), Proc. Eleventh Int. Scientific Cong. on the Cultivation of Edible
Fungi, Australia, 1981. Sydney. vol. 11.
- Wood, A. 1992. Another look at Australian mushrooms. Alumni Papers, Univ. New
South Wales. Mar./Apr./May. p. 14-16.
- Young, T. 1994. Common Australian fungi--A naturalist's guide. Univ. New South
Wales Press. Sydney.
*Thanks to the Rural Industries Research and Development Corporation for
scholarship funding; INRA-Bordeaux for cultures; N.G. Nair and R. Tolson for
supervision.
Table 1. Location and environment of Lepista isolates at time of
fruiting.
Country | Strain | Location | Environment |
Australia | A1, A4 | New South Wales | Warmz |
| A2, A3 | New South Wales | Cooly |
France | F1 | Landes | Warmx |
| F2 | Gironde | Warmx |
| F7 | Pyrenees | Coolw |
| F8 | Haute Alps | Coolw |
zMaximum temperature 24°C, minimum temperature 8°C
yMaximum temperature 20°C, minimum temperature 4°C
xAverage day temperature 14°C
wAverage day temperature 11°C
Table 2. Response of Australian and French Lepista isolates temperature.
Isolate | Maximum radial growth (mm2)z | Optimal temperature (°C) |
A1 | 32.6 | 25-30 |
A2 | 25.7 | 25 |
A3 | 24.7 | 30 |
A4 | 24.7 | 25 |
F1 | 12.7 | 22-25 |
F2 | 14.0 | 24 |
F7 | 13.0 | 22-24 |
F8 | 12.0 | 24-25 |
zAustralian isolates almost double hyphal growth of French
isolates.
Last update June 24, 1997
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