A study of mycelium characterization of several wild genotypes of the button mushroom from Iran

Morphology characteristics of mushroom mycelia in solid media are important because these characteristics are means to predict further mycelial growth into the compost, casing layer, and total yield. It has been well-known that many species of edible mushrooms, including Agaricus bisporus, grow in wilderness of Iran. To the best of our knowledge, no study has been done to characterize the mycelial growth of Iranian wild isolates of A. bisporus. Mycelial characteristics of six samples of Iranian wild isolates, along with three samples of commercial isolates were studied in compost extract-based media. Characteristics of mycelial morphology in the solid media included texture, density, color, radial growth rate (mm.day-1) and sectoring. In addition, mycelial morphology in the liquid media included texture, color, growth rate and duration of filling vials. Wild isolate As005 showed normal and strandy mycelia, while most of the other wild isolates showed a mixture of strandy-fluffy texture. The highest and lowest radial growth rates were recorded for As0011 and As001 with 2.87 and 1.97 mm per day, respectively. The results showed no symptom of severe sectoring, stromatal mycelia or color change during seven subsequent subcultures. Taken together, wild isolates As003 and As005 may be more likely to achieve higher productivity and best mycelial morphology, compared to the other wild isolates.