A diverse group of plant-growth promoting bacteria were isolated in button mushroom (Agaricus bisporus) media to investigate the plant-growth promoting traits of compounds including indole acetic acid (IAA), ammonia, 1-aminocyclopropane-1- carboxylic acid deaminase, siderophore, and hydrogen cyanide. Twenty-one bacterial strains showing positive effects for all the test traits were selected and classified to confirm bacterial diversity in the media habitat. Plant-growth promoting traits of the isolates were also assessed. All strains produced IAA ranging from 20 μg/mL to 250 μg/mL. Most of the isolates produced more than 80% siderophore. Four strains (Pantoea sp., PSB-08, Bacillus sp., PSB-13, Pseudomonas sp., PSB-17, and Enterobacter sp., PSB-21) showed outstanding performances for all the tested traits. In a bioassay of these four strains using mung bean plant, the best growth performances (23.16 cm, 22.98 cm, 2.27 g/plant, and 1.83 g/plant for shoot length, root length, shoot dry weight, and root dry weight, respectively) were obtained from the plants co-inoculated with Bacillus sp., PSB-13. The resultant data indicate that button mushroom media have got a diverse group of bacteria with plant growth promoting abilities. Thus, the media could be a good recycling resource for using to an effective bio-fertilizer.

본 연구에서는 한국에서 개발한 23개의 양송이 품종과 42개의 도입품종의 유전적 다양성과 집단 구조를 SSR 마커를 이용하여 분석하였다. 양송이 품종의 NA는 약 13, HO는 약 0.59, HE는 약 0.74, PIC값은 약 0.71 이었다. 양송이 품종은 군집분석에 의하여 3개의 Group으로 구분되 었고 다양한 국가의 품종으로 구성된 Group2의 다양성이 높았으며, 구조분석에 의하여 2개의 subpopulation으로 구분되었고, 품종의 수가 많은 Pop2의 다양성이 높았다. 한국의 양송이 품종들은 주로 Group 3에 분포하고, subpopulation 간 분포에는 큰 차이를 보이지 않았다. 본 연구의 결과는 양송이의 육종소재의 개발, 다양성 확보 등과 같은 품종의 개발과정에 이용될 수 있을 것이다.

A. bisporus is the fifth most cultivated mushroom in Korea, and approximately 10,757 tons were cultivated in 2015. The genetic diversity of collected strains in Korea and commercial cultivars was analyzed using inter-simple sequence repeat (ISSR) markers. ISSR markers known to be comparable among A. bisporus spp. were selected from various markers. Totally, 16 markers, namely the ISSR markers 807, 808, 810, 811, 834, 835, 836, 841, 842, P3, P8, P17, P22, P30, P38, and P39, were evaluated to discriminate between ASI 1110, 1114, 1115, 1238, 1246, 1365, 1366, and 1369 for selecting suitable markers in 16 markers. The ISSR markers P31, P38 and P39 exhibited various fingerprints that could help classify the strains in species. Using the three markers, genetic relationships among 39 strains, including commercial cultivars, such as SaeA and SaeYeon, were analyzed using the UPGMA method. The results of the analysis of the genetic relationships between commercial cultivars and collected strains in Korea confirmed that the commercial cultivars were different from the collected strains in Korea. These results suggested that the ISSR markers P31, P38, and P30 could be used for selecting the commercial cultivars of A. bisporus.

The white button mushroom, Agaricus bisporus, is commercially the fifth most important edible mushroom, accounting for the production of 9,732 tons of mushrooms in Korea in 2015. The genus Agaricus has been known for its potential to degrade lignocellulosic materials. Chemical analyses carried out during the cultivation of A. bisporus indicated that the cellulose, hemicellulose, and lignin fractions were changed preferentially for both vegetative growth and sexual reproduction. We screened A. bisporus strains for effective biodegradation through extracellular enzyme activity using cellulase, xylanase, and ligninolytic enzymes. The enzyme biodegradations were conducted as follows: mycelia of collected strains were incubated in 0.5% CMC-MMP (malt-mops-peptone), 0.5 Xylan-MMP, and 0.5% lignin-MMP media for 14 days. Incubated mycelia were stained with 0.2% trypan blue. Eighteen strains were divided into 8 groups based on different extracellular enzyme activity in MMP media. These strains were then incubated in sterilized compost and compost media for 20 days to identify correlations between mycelial growth in compost media and extracellular enzyme activity. In this study, the coefficient of determination was the highest between mycelial growth in compost media and ligninolytic enzyme activity. It is suggested that comparison with ligninolytic enzyme activity of the tested strains is a simple method of screening for rapid mycelial growth in compost to select good mother strains for the breeding of A. bisporus.

Twenty Inter simple sequence repeat (ISSR) primers were used to assess genetic diversity of 64 Agaricus strainsincluding 45 A. bisporus strains and other 19 Agaricus spp. ISSR primers, (GA)T, (AG)YC, (GA)C and (CTC) amplified PCRpolymorphic bands between the Agaricus species or within A. bisporus strains. PCR polymorphic bands were inputted forUPGMA cluster analysis. The varieties, Saea, Saedo, Saejeong and Saeyeon that have recently been developed in Korea wereinvolved in the same group with closely genetic relationship of coefficient similarity over 0.92, whereas, other Korean strains weregenetically related to A. bisporus strains that were introduced from USA, Eroupe and Chinese. Furthermore, ISSR-PCRpolymorphism could potentially be used to identify homokaryon isolates.

Twenty Inter simple sequence repeat (ISSR) and 30 SSR primers were used to assess genetic diversity of 64 Agaricus strains including 45 A. bisporus strains and other 19 Agaricus spp. Of them, four ISSR primers, (GA)₈T, (AG)₈YC, (GA)₈C and (CTC)₆and seven SSR markers produced PCR polymorphic bands between the Agaricus species or within A. bisporus strains. PCR polymorphic bands were inputted for UPGMA cluster analysis. Forty five strains of A. bisporus are genetically clustered into 6 groups, showing coefficient similarity from 0.75 to 0.9 among them. The varieties, Saea, saedo, Saejeong and Saeyeon that have recently been developed in Korea were involved in the same group with closely genetic relationship of coefficient similarity over 0.96, whereas, other strains were genetically related to A. bisporus strains that were introduced from USA, Eroupe and Chinese.