Mushroom breeding program in Iran

Abstract

Mushroom cultivation is a newly established, but growing industry in Iran. There are about 120 producers with a total of about 20,000 tones per year in the country. Agaricus bisporus consists of more than 85 percents of the total production of all mushrooms produced in Iran. Its yield average is about 12-15 kg/m2, while in the global production it is about 27-30 kg/m2. This is mainly due to using strains of genetically weak performance. Since ten years ago a breeding program was started with emphasis on breeding high yielding strains in Mashhad. The short-term effort consisted of selection among single spore isolates and multispores cultures with a better performance in yield. The long-term effort consisted of employing of heterosis in hybrid strains. To reach the aim, more than 350 homokaryone isolates were selected through RAPD markers followed by yield trials from commercial and domestic strains, and crosses were made in many combinations using diallel method. Selection among spores of commercial strains could somehow recover their potential genetic capacity, so that an average of 22 Kg/m2 was recorded in the selected strains. Using growth type as a marker, it was possible to decrease the number of isolates in final stages of selection for homokaryones in solid medium or spawn. Cluster analysis based on average of band numbers emerged by RAPD markers, could separate homokaryotic and heterokaryotic isolates in two distinct groups. Some hybrids showed a better mycelia growth and a considerable higher yield than their parents. Efforts are now being made to collect wild strains of Agaricus bisporus in Iran and evaluating them for desirable genes including resistance to pest and diseases.