This experiment was performed to select the most suitable species of oyster mushroom for cultivation during summer season in Korea. The selection was made based upon mycelial growth on the ricestraw substrates, fruiting under hot weather conditions during the summer season in Korea and potential high productivity using six cultures from South-east Asia. The newly selected strain of Pleurotus sajor-caju (ASI 2070) grew well on the rice straw substrates and produced the higher yields of sporophores than other cultures tested. The primordia of the mushroom were formed between 10 to . The optimal temperature for fruiting ranged from 20 to .
The experiment was performed to find out the possibilities to detect virus infection in oyster mushrooms, Pleurotus species by analysis of doublestranded ribonucleic acid (ds RNA). Ds RNA segments were extracted from virus infected isolates which grew abnormally. But virus free isolates didn't show any ds RNA segments. The ds RNA was consisted of one large segment of 8100 base pairs (bp) and 4 smaller segments with 2170, 2120, 1980 and 1984 bp. Whereas, cell free virus particles showed only one larger ds RNA segment. The ds RNA was dissolved by RNase A in low salt, 0.1 M SSC and melted at . It was possible to use the ds RNA analysis for detecting virus infection directly from the host cells.