MUSHROOM PRODUCTION

Selection of Strains:
For successful mushroom production, it is necessary for each grower to produce as economically and efficiently as possible the highest quality of mushrooms. This can be accomplished among other requirements, by selecting the best strains which should be high yielding , visually attractive, having desirable flavour, and resistance to adverse climate and pests and diseases. Presently, there are many strains of white, cream and brown varieties in cultivation. The brown variety is the natural mushroom and considered to be the most vigorous form. It tolerates and adverse conditions better than the white variety.
A snow white mushroom first appeared amongst a bed of mushroom in the USA and ever since the variety has dominated the mushroom industry throughout the world, although it has a very high limited shelf-life. Where growing conditions tend to be on the dry side and humidity cannot be correctly controlled the brown mushroom should be grown. New superior strains are through selection, hybridization and induced mutations continually introduced by mushroom research laboratories and spawn makers. In India, S 11, S 649 and S791 are the good strains available. These strains were originally introduced from reowned commercial spawn makers, Somycel and darlington. Now these strains are well adapted in the Indian climate and are very popular with the growers.
Maintenance of Strains:
Three methods are known by which strains can be propagate. these are multispore culture, tissue culture and mycelium transfer. By periodic subculturing of the mycelium on a suitable agar medium, the span strains can be kept for many years in a fairly good state. However, the frequent subculturing of the strain may result in its degeneration. Maintenence of strain by multisporous culture is only possible if new multispore cultures are compared with the original strain before the original multisporous culture would show much genetic variation.
In the tissue culture, small pieces of fruit bodies are cut under sterile conditions and inoculated on a nutrient medium. Mycelium growing out of these tissue can provide the starting point for subsequent spawn production. However, it is commonly observed that tissue cultures often give lower yields than the original cultures. Of these 3 methods, mycelium transfer is most reliable but it is essential that the performance of the mycelium is continually checked in order to detect any degeneration-like slow-growing matted mycelium or fluffy mycelium with abnormal growth rate.
Spawn:
The propogating material used by the mushroom growers for planting beds is called spawn. The spawn is equivalent to vegetative seed of higher plant. Quality of spawn is basic for the successful mushroom cultivation.
At present, the pure culture spawn has been the basis of modern spawn production units all over the world. The manufacture of the pure culture spawn is done under scientifically controlled conditions which demand a standard of hygiene as in a hospital operation theatre. Equipment and substrate used for spawn are autoclaved and filtered air is passed during the inocluation ensures complete freedom from contamination.