Isolation and determination of mutated characteristics of the result of irridation by UV ray in white button mushroom (Agaricusbisporus).

Abstract:    The white button mushroom (Agaricus bisporus) is one of the most widely cultivated edible mushroom species in the world. Despite the long term cultivation and its economic importance, the breeding efforts in the this species have been limited. The main reason is typical life cycle that restricte cross ability between single spores of different strains. So variability in Agaricus bisporus populations is very low and the most of available strains in the markets are quite homogenous. One of the routine ways to induce the variability is using mutagens like UV irradiation. So, in the present study we used three methods for mutagenesis induction. In the first method, the fragments of mycelium were treated with UV irradiation for 8 exposure times (0, 4, 8, 16, 24, 48, 72 and 96 hours). In the second method, spore suspension was exposed to UV irradiation for 6 exposure times (0, 60, 90, 120,180 and 240 minutes). Then 1 ml of sterile spore suspension immediately were exposed to UV radiation for 6 times (0, 1, 5, 10, 20 and 40 minutes). The UV lamp (10-W) placed about 10 cm above the samples. Spawn running time acquisition, pin production rate and harvest, fruit body number, fruit body size, fruit body yield, biological efficiency, dry weight, ash percent and protein content were evaluated. Considering the fact that our main idea in this research was to inducing variability in A. bisporus, the overall results showed that all the methods were promising. This study revealed that mutagenesis induction by UV could be useful and quick way to induce diversity in A. bisporus. Also the UV could be low cost efficient method in the breeding program of this nutrition mushroom. Keywords: Agaricus bisporus, biological efficiency, irradiation, mutagenesis, mycelium, spawn