Volume 12 Part 1 Article 10
Title: Selection of Sporeless or Poorly-Spored Induced Mutants from Pleurotus ostreatus and Pleurotüs pülmonarius and Selective Breeding
Authors: M. Imbernon and J. Labarere
People exposed to spores of Pleurotus taxa while picking or selling the mushroom may develop respiratory allergies. These allergic responses have become more frequent over the past few years as aresult of the large-scale production of this mushroom. They are induced by antigens present on the spore surface (Noster U. et al. 1977; Lopez M. et al. 1985; Florence S. et al. 1985). This serious problem has caused increased production costs and may sooner or later prevent the further extension of Pleurotus cultivation.
In addition to this serious health problem, the presence of spores has other drawbacks. During the ccrmejrcialization process, spores settle on fruit bodies, germinate, and lead to the formation of a whitish velvety film which gives an unpleasant appearance to the mushrocm. Also, they may be a source of pollution in both rural and urban areas because the spores emitted may include a number of new genotypes likely to attack wood or trees.
To overcome this difficulty, a program has been developed for obtaining sporeless strains in the two species most commonly grown in France: Pleurotus ostreatus and Pleurotus pulmonarius (Imbemon M. et al. 1984; Labarere J ., Imbemon M. 1985).
The first step of this breeding program was concerned with selecting sporeless mutants and determining their characteristics. Low yields and abnormal morphologies were generally observed. The second step of the project was thus aimed at inproving these two characteristics. Successive vegetative hybridization cycles were carried out between dikaryotic sporeless mutants and wild-type homokaryons from geographically distinct strains to obtain sporeless strains having yields and morphologies at least comparable to those of spored or non-spored controls currently on the market.Please login to download the PDF for this proceeding.