Mushroom Culture

Classification of Mushrooms

Classification of Mushrooms

• Mushroom is a fleshy fruiting body of some fungi arising from a group of mycelium buried in substratum. Most of the mushrooms belong to the Sub- Division: Basidiomycotina and a few belong to Ascomycotina of Kingdom-Fungi.
• It is reported that there are about 50,000 known species of fungi and about 10,000 are considered as edible ones. Of which, about one hundred and eighty mushrooms can be tried for artificial cultivation and seventy are widely accepted as food. The cultivation techniques were perfected for about twenty mushrooms and about dozen of them have been recommended for commercial cultivation. However, only six mushrooms are widely preferred for large-scale cultivation. They are :

1. Paddy straw mushroom - Volvariella spp.
2. Oyster mushroom - Pleurotus spp.
3. Button mushroom - Agaricus spp.
4. Milky mushroom - Calocybe spp.
5. Shiitake mushroom _ Lentinulla spp.
6. Jew’s ear mushroom - Auricularia sp.

Mushroom morphology

A . Agaricus bisporus: The Button Mushroom

• Cap: 3-16 cm, convex to broadly convex or nearly flat in age; dry; smooth or with pressed-down or small scales; white in some varieties, brown in others. Gills free from the stem; close; pinkish to pinkish brown at first, becoming dark brown to blackish. Stem 2-8 cm long; 1-3 cm. thick; sturdy; more or less equal; smooth or with small scales below the ring; white, often bruising brownish; with a ring that sometimes disappears in maturity. Flesh ¬white and firm; usually bruising and staining brownish (see top illustration).Odour and taste pleasant.Chemical Reactions -cap not yellow with KOH. Spore print brown .Microscopic Features -spores 5.5-8.5 x 4-6.5 µ; elliptical; smooth. Basidia 2-spored.

B. Pleurotus spp.:The Oyster mushroom

• The cap of oyster mushroom is tongue shaped , maturing to a shell shaped form , 50-150 mm in diameter , whitish to grey to blue grey in colour . Flesh is thin and white , margin is occasionally wavy, gills are white, decurrent , broadly spaced, stem attached in an off - centred fashion and is short at first and absent in age . Spores are whitish to lilac grey in mass, mycelium whitish , fast growing rhizomorphic to linear . Basidia tetrapoplar , producing 4 haploid spores, heterothallic, clamp connections present . Because of the allergic nature of spores , some sporeless strains have also been developed.

C. Volvariella spp.:The Paddy straw mushroom

• Mushrooms are white initially, become dark tan in colour as the veil tease and then changes to a pale tan with age. Fruiting bodies are small when young enveloped by a sheath like universal veil, which soon breaks as fruit bodies mature , leaves an irregular cup-like sack at the base of the stem known as volva. Cap 5-15 cm broad , egg shaped and expands to campanulate or convex with slight umbo . Gills are free, white first and soon pinkish, spores are pinkish to pinkish brown in mass ,7.5–9 x 4–6 µ in size. Stem 4-20 cm long, solid, smooth and white to yellowish in colour. Stem base is encased in a thick volva .Basidia are tetrapolar , producing four haploid spores , primary homothallic, clamp connections are present, form cheilocystidia, pleurocystidia and chalamydospores.

Mushroom Poisoning and treatments
Eating poisonous mushrooms may cause different types of reactions which can broadly be classified as follows :

1. Gastric disorder: The poison causes serious gastric disturbance, it chiefly acts by exciting and then paralysing the central nervous system as by Amanita muscaria or poison containing irritant which cause gastric enteritis by direct action on the mucous membrane of the digestive system.e.g Gyromitra esculenta.
2. Nervous disorder: It causes degeneration of cells , especially of the nervous system and grandular parenchymatous tissues like liver as in case of Amanita phalloides.
3. Muscular disorder: There may be exciting of the muscular system , especially the smooth muscular fibre as it is there in the uterus , vessels etc.
4. Haemolytic disorder: There can be destruction of blood or haemolysis as in case of Amanita rubescens

Treatments :

• All the collectors of wild mushrooms should be careful about mushroom poisoning and have some knowledge of the first –aid remedies in case of mushroom poisoning and then the patient should immediately be taken to a doctor.
• The patient should be made to cover his body with a blanket , lie down calmly and given the first – aid treatment till the arrival of the doctor.
• Removal of poison from the stomach : The patient may be made to vomit by putting his fingers inside the mouth or throat or by giving warm water with one tablespoonful of mustard seeds or apomorphine. The stomach should be completely washed by means of a stomach tube . One can also give some sedatives like warm water , 4--5 tablespoonful of warm milk , two tablespoonful of olive oil beaten with the yolk of an egg etc.
• Elimination of the toxin: The ingested poison in the stomach can be removed by putting charcoal powder in the stomach and if it has already been absorbed in blood then subcutaneous injections of atropine or other antidotes can help in removing the effect of poisoning.