Shiitake Strains Research Articles

Comparative performance of exotic strains of shiitake (lentinus edodes (Break.) sing) on saw dust bag-logs

Performance studies were conducted on three strains of shiitake on saw dust bag-logs. The minimum of 150-160 days were required for the first harvest. R-26 strain was found to be the best followed by WC-730 and Solan strains with reference to the yield of mushroom.

Growing Shiitake Mushroom on Hardwood Sawdust in the Greenhouse

Seven strains of shiitake mushroom [Lentinula edodes (Berk.) Pegler] produced spawn in culture vessels containing hardwood sawdust amended with YVMBS (yeast extract, multigrain oatmeal, brown sugar) broth within 35 to 45 days after mycelia inoculations. Under greenhouse conditions, shiitake basidiocarps (mushroom fruit) appeared from 1 to 3 months after spawn inoculations of the hardwood sawdust amended with YVMBS broth. The shiitake mushroom strains LE2, LE1, LE6, and LE5 had 10.4, 7.3, 2.5, and 1.6 times more fresh harvested basidiocarps, respectively, on the amended hardwood sawdust compared to the controls. The amount of basidiocarps produced by the shiitake strains LE3, LE4, and LE7 was the same on both hardwood sawdust treatments. The basidiocarps of LE1, LE2, LE3, LE4, and LE5 were averaged 5 inches (12.7 cm) in diameter, however, the basidiocarps of LE6 and LE7 were averaging only 2 inches (5.1 cm) in diameter. The only pests of the shiitake basidiocarps in the greenhouse were slugs, but they were easily controlled by applying table salt. The start up cost of inoculating 100 shiitake spawn blocks on hardwood sawdust on one bench in the greenhouse was $77. The start up cost of inoculating shiitake spawn on 100 logs was $1,329.75. In 1 year, shiitake strains LE1, LE2, LE5, and LE6 produced 19.5, 20.2, 7.9, and 4.5 lb (8.8, 9.2, 3.6, and 2.0 kg), respectively, of harvested fresh basidiocarps on amended hardwood sawdust in the greenhouse. The mushrooms retail for $3.20 to $4.20/lb ($7.05 to $9.26/kg). The use of the hardwood sawdust amended with YVMBS broth for shiitake production in the greenhouse has considerable economic potential for shiitake mushroom growers.

Shiitake Mushroom Growth on the Formulated Culture Media, Production of Spawn, and Basidiocarps in the Laboratory

Culture media YMMBSA (yeast extract, malt extract, multigrain oatmeal, brown sugar, agar), YVMBSA (yeast extract, V-8 vegetable juice, multigrain oatmeal, brown sugar, agar), and YVMSA (yeast extract, V-8 vegetable juice, multigrain oatmeal, sucrose, agar) and broths YVMBS (yeast extract, V-8 vegetable juice, multigrain oatmeal, brown sugar), YVMS (yeast extract, V-8 vegetable juice, sucrose), and MVBS (multigrain oatmeal V-8 vegetable juice brown sugar) were formulated and demonstrated to be excellent media and broths for growing shiitake mushrooms [Lentinula edodes (Berk.) Pegler] in the laboratory. When a portion of the unopened basidiocarp or mushroom fruit (cap or stipe) was isolated on PSA (potato sucrose agar) medium and transferred to the formulated culture media, the mycelia significantly ramified to flocculent (wooly or fluffy) growth texture within 20 days. For the first time, shiitake mushroom basidiocarps have been induced on the formulated plated media within 20 to 35 days. In tissue culture vessels, mycelia grew well on substrates composed of maple, oak, maple + oak, maple + vermiculite, and oak + vermiculite which had been amended with the broths YVMBS, YVMS or MVBS, attaining spawn texture in 25 to 30 days. Shiitake basidiocarps appeared on the tissue vessels, Magenta GA-7, in 2.6 to 4.1 months. Shiitake mushroom strains, LE1, LE2, LE6, LE7, and LE8, attained flocculent mycelia on the formulated culture media YMMBSA, YVMBSA, and YVMSA in 20 days. Growing the same shiitake strains in the bigger tissue culture vessels, P4928, containing hardwood sawdust amended with broth YVMBS or YVMS or MVBS resulted in significantly larger volume of mycelia growth and spawn texture was attained in 35 to 45 days. Shiitake basidiocarp initials or pins were induced on the spawn blocks in 3 to 5 days after the blocks were squeezed off from the sides of the tissue culture vessels. These results are the first that the formulated culture media considerably enhanced the growing of shiitake mushroom mycelia, production of spawn, and basidiocarps in less time (2.6 to 4.1 months after inoculation) in the laboratory. Basidiocarp productions of shiitake mushroom on amended hardwood sawdust may have an excellent economic potential commercially. It takes 1 to 2 years for basidiocarps to appear in shiitake spawn inoculated logs.

Genetic homogeneity of cultivated strains of shiitake ( Lentinula edodes) used in China as revealed by the polymerase chain reaction

Nineteen strains of shiitake (Lentinula edodes) which are used for spawn production for farms throughout mainland China were characterized by three arbitrarily-primed polymerase chain reaction (AP-PCR) profiles seven random amplified polymorphic DNA marker (RAPD) profiles and five restriction patterns (restriction fragment length polymorphism patterns of the PCR-amplified ribosomal DNAs; rDNA-RFLPs). For AP-PCR, 4–14 DNA bands were amplified for a particular strain while 1–9 DNA bands were amplified using RAPD. Among them only three of the strains tested showed different amplification profiles with most of the primers used. The others showed small differences in three or fewer DNA amplification profiles. All strains showed identical rDNA-RFLPs. The study indicates that cultivated strains of shiitake in China are genetically very homogeneous very like cultivated strains of Agaricus bisporus and Volvariella volvacea. However, our collection of L. edodes covers an enormous geographical area (approx. 1700 km N to S, 700 km E to W) and our results demonstrate that the shiitake industry in China depends on an extremely small gene pool. In comparison three wild strains collected from the same ecosystem in Fujian Province (SE China) showed more variable amplification profiles. This emphasises the importance of conservation of wild shiitake strains as a reserve of biodiversity for this important industry.

Selection and breeding of shiitake strains resistant to Trichoderma spp.

Bedlogs of shiitake, Lentinula edodes (Berk.) Pegler, are often attacked by Trichoderma spp. such as T. harzianum Rifai and T. polysporum Rifai, which produce antifungal substances and mycolytic enzymes. However, shiitake is more or less able to reject Trichoderma attacks. Shiitake cultures possess at least five straight-chain alcohols with double and triple bonds, which act as antifungal substances. Trichoderma inoculation tests for shiitake cultures showed that the resistance of shiitake in a wood-powder medium correlated positively with that in bedlogs when T. harzianum was used. Screening assays using the wood-powder medium showed some highly resistant and susceptible strains among 164 different wild shiitake strains. Monokaryons derived from basidiospores of a highly resistant strain, TMI-407, had high rejecting abilities compared with those from a susceptible strain, TMI-1161. Crossing between monokaryons from the two strains revealed that resistance was dominant. In general, these resistant mycelia produced much more antifungal substances than did susceptible mycelia. Key words: Lentinula edodes, shiitake, mushroom cultivation, resistance to Trichoderma spp., selection method, antagonism.

Shiitake cultivation: Gas phase during incubation influences productivity

To test the effects of gas levels during incubation on mushroom production, we grew two strains of shiitake, Lentinula edodes, on a sawdust medium inside plastic mushroom-growing bags having different amounts of ventilation. During 77 days of incubation, oxygen and carbon dioxide levels inside the bags varied with: 1) the fungus strain, 2) the metabolic activity and stage of development of the fungus, and 3) the size of the microporous filter patch ventilating the bag. Total mushroom yield, fruitbody size, the number of mushrooms produced, and the severity of contamination during cropping were affected by filter patch size. Each strain required a different amount of ventilation in order to achieve optimum mushroom production.

706 (PS 6) THE INTERACTIVE EFFECTS OF SHIITAKE MUSHROOM STRAINS AND WOOD SPECIES ON THE YIELD OF SHIITAKE MUSHROOMS

Shiitake mushrooms are grown on hardwood logs or bagged synthetic hardwood media. Domestic production of shiitake mushrooms was 3.9 million pounds in 1990-91 with a value of $16.3 million. Production of shiitake is expanding throughout the U.S., but shiitake mushroom strains are so environmentally sensitive, and wood species so diverse that evaluations of shiitake strains and wood species must be conducted on a regional basis to provide reliable results for producers. The objectives of this project were to determine the best wood species, the most productive shiitake strain and the species/strain interaction for the southern region. At the end of 30 months, there were very significant (P<0.01) differences among strains and wood species and a significant (P<0.05) interaction. Five wood species--sassafras, white oak, red oak, sycamore, and cherry--were each inoculated with 8 shiitake spawn strains–WR46, V3, WW44, West Wind, Twice Flowering, WW70, CW25, and WR85. Logs were soaked as needed and mushrooms were harvested at marketable sizes. The shiitake strains WR46, WW44, and WW70 produced the highest yields over all wood species and red oak and white oak were the most productive tree species over all shiitake strains. The optimal shiitake strain × wood species combinations were WW44 and WR46 on red oak and WW70 on white oak.

Respiratory Illness in Workers of an Indoor Shiitake Mushroom Farm

Abstract Shiitake mushrooms (Lentinus edodes), the second most important mushroom in world commerce, are usually grown on logs outdoors. Because of the relatively short harvesting period and weather dependency of shiitake strains that are cultivated outdoors, there is a trend toward indoor cultivation of strains that can permit year-round production. An evaluation of an indoor shiitake farm was conducted following reports that workers of the facility were experiencing symptoms of respiratory illness. During private interviews that included the administration of a questionnaire, 11 workers reported seven or more symptoms which they had experienced either during work or shortly after leaving work; six of these workers reported 15 or more symptoms. Predominant symptoms were dry cough, nasal discharge, sneezing, chest tightness, productive cough, and dyspnea. Based upon the results of the acute symptoms questionnaire and preliminary bioaerosol sampling, the management of the shiitake farm discontinued operati...

Identification of Shiitake strains and some other basidiomycetes : Protein profile, esterase and acid phosphatase zymograms as an aid in taxonomy

Lentinula edodes strains exhibited a typical total protein pattern when native soluble proteins were separated by isoelectric focusing at a pH gradient of 3·5–10. Intraspecies variation was found when using a narrower acidic pH gradient of 4–6. Esterase zymograms showed variation between the shiitake strains. However, the variation was wider between different wood-rotting species. Although the acid phosphatase isoenzyme patterns were all similar in the shiitake strains, variation was observed between the different basidiomycete species. The use of acid phosphatase and esterase as an aid in the taxonomy of wood rotting basidiomycetes is discussed.