Cross breeding continues to be the principal method, but it is accompanied by analyses of RAPD or RFLPs methods. The use of genetic makers is straightforward for monogenic traits that segregate in distinct phenotypes, such as cap colour. These markers have been used to introduce the brown cap colour of a wild line into a commercial large hybrid via introgression breeding. Another example is the introduction of sporeless trait to the commercial strain of Pleurotus ostreatus. The complex traits such as yield, resistance to disease and quality characteristics, more than one quantitative trait locus (QTL) have been found and used in practice. The transformants or transgenic mutant strains were obtained by Agrobacterium system or particle bombardment.
Pharmaceutically active mushroom compounds continue to be the main subject of most researches, including isolation, chemical structures and experiments in vitro or in vivo. At least 651 species representing 182 genera of hetero- and homobasidiomycetes mushrooms contain antitumor or immunostimulating polysaccharides. The lipid fraction was found to contain a compound with antitumor activity, subsequently identified as ergosterol. The lipid fraction exhibited antioxidant activity and inhibited the cyclooxygenase enzymes. Ergosterol was again identified as one of the most active constituents. Its inhibition can result in the inhibition of tumor development, and it appears to be beneficial even in some established tumors. Other mushroom constituents may inhibit promotion or progression by exerting direct cytotoxicity against tumor cells, interfering with tumor angiogenesis, or upregulating other nonimmune tumor-suppressive mechanisms.