How to prevent mushroom spawn degeneration? Practical control methods

Spawn degeneration can lead to slow mycelial growth, weakened resistance to the environment, contaminant microorganisms and so on, an earlier or delayed fruiting body formation period, and indistinct flushes of mushrooms. There are many causes of spawn degeneration, among which impure spawn and gene mutation are the main reasons; in addition, excessively high temperatures and mixed cultivation of different strains can all cause spawn degeneration.

Measures to prevent spawn degeneration include: ensuring pure culture of the spawn, taking care not to use spawn contaminated by foreign microorganisms, and not cultivating in close proximity connected to each other; strictly controlling the number of subcultures, reducing mechanical damage, and ensuring spawn vitality; storing spawn at appropriately low temperatures - for low-temperature strains such as the button mushroom (Agaricus bisporus) and shiitake (Lentinula edodes), 4°C is favorable for preserving mycelial vitality, while for high-temperature strains such as the straw mushroom (Volvariella volvacea), 16°C is favorable for preserving mycelial vitality; avoiding repeated subculturing in a single medium; spawn should not be used for too long a time, as over-aged spawn will age, and aging is organically linked to degeneration, so spawn with weak viability is very prone to degeneration; spawn should be rejuvenated regularly, under conditions of suitable temperature, appropriate pH, sufficient oxygen, and culture free of contaminant microorganisms; carry out spore isolation every year to discover superior strains through sexual reproduction, and use tissue isolation to consolidate the genetic characteristics of superior strains.