Abstract
Shiitake (Lentinula edodes) cultivation and uptake of a fungicide, thiabendazole (TBZ) into fruit bodies cultivated on a sawdust media with fungicide at different concentrations including practical one (0.012%) were investigated. When shiitake inoculated on non-sterilized medium (test 1), mycelia did not grow on the medium with even 1.2% TBZ. When shiitake was inoculated on sterilized media with TBZ (test 2), the addition of TBZ at 0.12%〜1.2% decreased mycelial growth as compared with the control without fungicide. When shiitake and Trichoderma harzianum were simultaneously inoculated on sterilized media (test 3), Trichoderma mycelia grew vigorously on the media containing TBZ at concentrations up to 0.0012%, but did not grow the medium over 0.012%. The shiitake spawn grown on 1.2% TBZ medium delayed the browning of spawn surface and showed slightly high pH as compared with the control spawn. The spawn did not mature during the 90 day-incubation due to high TBZ concentration. The first flush on 0.12%〜1.2% TBZ media delayed as compared with that on the control. The first flush on the test 3 spawns at 0.12%〜1.2% TBZ delayed as compared with that of the corresponding test 2 spawns. The yield of first flush fruit bodies on test 2 spawn at 0.12% TBZ medium was lowered as compared with that of the control, while the total yield was almost the same as that from control spawn. However, the yields of the first flush and the total from 1.2 % TBZ spawn decreased to 1/6 times as compared with the control. The TBZ concentrations in fruit bodies were increased with higher concentrations of TBZ added into the media. The TBZ concentrations in fruit bodies from 4 different strains were below the law regulation levels when cultivated on at 0.012% TBZ media supplemented with various nutritional additives. The TBZ concentration in the second flush fruit bodies produced by soaking the TBZ free spawn into 0.012% TBZ after the first flush remained under the law regulation level.
