New Record of the Genus Calyptella from Korea

Calyptella capula is reported for the first time in Korea. It was found in spring in Chungcheongbuk-do, central Korea, growing in a dead stalk of Sesamum indicum. A description and molecular phylogenetic analyses are reported.

Occurrence of Internal Stipe Necrosis of Cultivated Mushrooms (Agaricus bisporus) Caused by Ewingella americana in Korea

The internal stipe necrosis of cultivated mushrooms (Agaricus bisporus) is caused by the bacterium Ewingella americana, a species of the Enterobacteriaceae. Recently, Ewingella americana was isolated from cultivated white button mushrooms in Korea evidencing symptoms of internal stipe browning. Its symptoms are visible only at harvest, and appear as a variable browning reaction in the center of the stipes. From these lesions, we isolated one bacterial strain (designated CH4). Inoculation of the bacterial isolate into mushroom sporocarps yielded the characteristic browning symptoms that were distinguishable from those of the bacterial soft rot that is well known to mushroom growers. The results of Gram stain, flagellal staining, and biochemical tests identified these isolates as E. americana. This was verified by pathogenicity, physiological and biochemical characteristics, and the results of an analysis of the 16S rRNA gene sequences and the fatty acids profile. This is the first report of the isolation of E. americana from cultivated white button mushrooms in Korea.

An Improved Compost Using Cotton Waste and Fermented Sawdust Substrate for Cultivation of Oyster Mushroom

A composting technique was assessed to enhance efficiency in oyster mushroom substrate. Poplar sawdusts and by-product of winter mushroom added by 10% of rice bran were composted outdoors at 20degrees C to 28degrees C for 12 days. The duration of fermentation was shortened 3 days in fermented sawdust plot. The yield obtained from waste cotton substrate with fermented poplar sawdust was 742 g, whereas the yield from control 663 g. In addition, the substrate with by-product of winter mushroom was the most effective to composting. It was useful to apply the fermented sawdust and by-product to waste cotton for compost and sporophore production of oyster mushroom.

Breeding of Flammulina velutipes Strains Adaptable to Elevated-temperature

Winter mushroom, Flammulina velutipes, needs low temperature during its cultivation. To save on farm costs, especially during summer, a strain adaptable to a higher or elevated-temperature must be developed. At the start of breeding program, parental strains which could endure high temperature were obtained. Seuenty four dikaryotic strains were collected and divided into four groups according to the nature of temperature. They also had different fruiting temperature. Finally we selected three brown strains ASI 4048, 4057 and 4072, and collected their spores. These selected strains can germinate even at a high temperature of 32degrees C, which were dramatically higher than the other strains. Based on these results, the new white strain adapted to mid-temperature by backcross mating was developed. Molecular markers were applied to select white fruit-body producing strains without cultivation. They showed a specific band which co-segregated with brown fruitbody forming strains in BC1F1 progenies. Selected white strains were tested under several elevated temperature conditions.

Analysis of Cultural Characteristics and Phylogenic Relationships of Collected Strains of Pholiota species

Cultural characteristics and phylogenic relationships were investigated and classified among collected strains in Pholiota spp. which contain P. adiposa, P. squarrosa, P. nameko etc. They were tested on the four different media (PDA, MCM, YM, MEA) and sawdust (Alder, Oak, Pine, Popular) substrates. There was a little variation according to the media and sawdust substrates, although PDA and popular sawdust substrate seemed to be better. Most strains showed white colonies, but some strains were brown. Mycelial growth length differed according to the strains. To classify species, the internal transcribed spacer regions (ITS) of the ribosomal DNA (rDNA) repeats from Pholiota spp. were amplified using polymerase chain reaction (PCR) and then sequenced. According to the analysis of ITS sequences, they were classified into five clusters. Their spacer regions were 644~700 nucleotides in length. The reciprocal homologies of each ITS region among these strains were ranged from 49.6~99.9%. The phylogenic analysis might give a criterion to classify species in the collected strains.

Characterization of Fruitbody Morphology on Various Environmental Conditions in Pleurotus ostreatus

This study investigated the morphological differences of P. ostreatus grown in the artificial environmental conditions such as humidity, temperature, ventilation, and watering. Oyster mushroom, which was cultivated on artificial environmental condition, was shown to have different morphology of fruitbodies. The optimum CO2 concentration for good morphology of P. ostreatus was 0.3%. But most fruitbody showed the morphologically low qualities in more than 0.5% of CO2 concentration. In the humidity in excess of 80% at 13~16degrees C, the best morphology of P. ostreatus was investigated. The growth of fruitbodies of P. ostreatus in the ventilation system was good at the wind velocity ranging from 0.2~0.5 fpms and expouring type. In other conditions, P. ostreatus generally showed the morphology closing to malformation.