Volume 10 Part 1 Article 16
Title: Characteristics of Some Pleurotus Strains from Florida, Their Practical and Taxonomical Importance
Authors: Sui-Fong Li and G. Eger
The cultivated Pleurotus ostreatus strains of the so called “Florida type” are remarkable in that they fruit under subtropical summer conditions. All strains that are in use to day descend from a single sporophore that was collected many years ago from a log in the Gainesville area (Florida, USA). Block et al. (1959) used a culture of this fungus for their experiments on mushroom cultivation on sawdust. Since then innumerous subcultures have been made and propagated under artificial conditions.
As long as the cultivation of P. ostreatus was in an experimental stage, organised breeding work was not done. Now Pleurotus cultivation is gaining importance throughout the world. Successful cultivation depends upon improved growing techniques and better strains. Strains adaptable to a broad range of temperatures are desired for two reasons. Firstly, vigorously growing cultures produce and accumulate considerable amount of heat when they are not well aerated. Aeration of the cultures causes desiccation and contamination if the air is not well moisturized and filtered. Using strains which grow more slowly reduces heat accumulation, but much growing spaces are required. Investments could be lowered by developing strains with a higher heat tolerance. Secondly, among the P. ostreatus strains available today, the European ones usually do not fruit if the temperature does not drop to 15°C or below for at least a few hours daily. Therefore without costly climatization their cultivation is limited to the cooler seasons. Unexpected warm weather can still cause grievous losses. The commercially used Florida strains fruit in a wider range of temperatures. However, their productivity is considerable less at temperatures below 15°C. Their flavour, appearance and storage qualities are inferior when grown at elevated temperatures. It has previously been shown that hybrids between European and American strains are possible (Eger et al., 1976), and they may have the desired characters of both.
Because the commercially used Pleurotus from Florida, kept so long under artificial conditions, may not be a proper starting material for a breeding programme, wild sporophores, of Pleurotus were collected in the Gainesville area in August, 1977, by Eger and San Antonio. Spores were saved for further breeding work. The spore prints of four specimens from different localities were used in this investigation. Several characteristics of these strains were compared with four European strains, including one commercial variety.Please login to download the PDF for this proceeding.