Effect of Plant Growth Promoting Bacteria (PGPR) on the Morpho-physiologicalProperties of Button Mushroom Agaricus bisporus in Two Different Culturing Beds

ABSTRACT: Edible mushrooms such as Agaricus bisporus are cultivated for food worldwide. Phase change from the vegetative to the reproductive stage and fruit body initiation of this mushroom were made by presence of casing layer which depended on physical, chemical and biological properties of this layer.The presence of bacteria in this layer has great impact on the performance of the ediblemushrooms. In the present study, in order to evaluation the effect of plant growth promoting bacteria on yield of edible mushroom an experiment was conducted as factorial arrangement based on randomized complete block design with three replications. First factor consisted of two substrate including fresh mushroom compost and municipal solid waste compost. Second factor consisted of bacterial treatments at six level include no-bacteria, IAA producing bacteria, ACC-deaminase producing bacteria, phosphate solubilizing bacteria and siderophore producing bacteria and a bacteria with all growth promoting traits. Analysis of variance showed that effect of growth promoting bacteria on mushroom yield was significant (P < 0.01). Highest mushroom yield observed in B4 treatment which increased fresh weight by 12.7 percent compared to control. Highest amounts of dry matter percentage and number of mushrooms were obtained in B3 treatments compared to control. Also Iron concentration in B5 treatment had significant increase compared to control with the amount of 88.1 mg/kg.