Evaluation of The Efficiency of Some Desert Plant Extracts in The Growth of Agaricus Bisporus and The Inhibition of Some of Its Pathogens

Abstract

Seven isolates of Pseudomonas spp. were isolated from the casing soil and 11 fungal isolates were isolated from the spent compost in the Mushroom Farm - College of Agriculture - Tikrit University. According to the pathogenicity test against Agaricus bisporus fruit bodies, the results showed that the highest infection rate was recorded in the bacterial isolate 1077by 77.45%, while the fungal isolate 1076 showed the highest pathogenicity against Agaricus bisporus fruit bodies by recording the highest infection rate reached to 81.23%. The pathogenic bacteria and fungi isolates were phenotypically identified to the species level as Pseudomonas tolaasii and Trichoderma harzianum, respectively. The results showed the alcoholic extracts of Atriplex tatarica and Haloxylon salicornicum were superior in the active substances compared to other extracts, the highest percentage of total alkaloids, tannins, saponins, phenols and flavonoids was 35.14, 44.79, 43.47, 32.05 and 31.66 mg/g in the alcoholic extract of A. tatarica, respectively, while the alcoholic extract of H. salicornicum had the highest percentage of glycosides, which amounted to 41.89 mg/g of the extract. The highest efficiency of A. tatarica alcoholic extract in inhibiting the pathogenic fungus T. harzianum, was recorded, as the colony diameter was 3.1 cm in concentration of 4 mg/mL compared to 8.9 cm in the control treatment, while the H. salicornicum alcoholic extract was superior in inhibiting the pathogenic bacteria at the same concentration, in which the inhibition zone was 15.67 mm compared to no inhibition in the control treatment. While there was little effect of alcoholic extracts of both plants on the growth of A. bisporus. The results of the dry powders effect for both plants showed that the highest inhibition against the pathogenic fungus T. harzianum was recorded by the A. tatarica powder at 2% concentration, reaching 5.01 cm, while the H. salicornicum powder showed the highest inhibition against the bacteria P.tolaasii at the same concentration in which the number of cells reached to 3.23 x 107 cells/mL compared to 6.6 x 107 cells/mL in the control treatment. The results also showed the highest growth of A. bisporus that reached 9 cm for all powdered concentrations of both plants.