Abstract:

The mushroom Cyclocybe aegerita（Agrocybe aegerita）is cultivated widely in China,with rich natural resources and varied genetic background. The confused nomenclature and complex mating behavior hamper the cognition of genetic breeding for C. aegerita. Strain groups of two species,C. aegerita and C. salicacola were employed,and special primer was designed for amplifying to acquire the mating locus fragment of strain group via genome sequencing and sequence analysis for the strain identification and phylogenetic construction. As results,two B mating loci were cloned from two stains of C. aegerita,and a fragment about 8 kb including rcb1,rcb2 and partial non-coding region were conserved. The special primers were designed based the fragments containing variable regions,and then 1-2 types of about 3.2 kb fragments（cbmr）from each tested strain were obtained after the amplification and clone sequencing of 35 strains in the conserved B mating region. The classification of strains based on the cbmr showed high fitness in phylogenetic tree with that of mitochondrial small-subunit （mtSSU）,but the former revealed the genetic background of strains more finely. Additionally,the variable regions provided efficient targeting sites for the group and mating type identification. In conclusion,based on the sequence characterization of B mating locus,the corresponding products can be obtained from all tested strains,which can be used as molecular markers for strain and B mating type identification of C. aegerita and C. salicacola.

Key words: Cyclocybe aegerita, B mating locus, phylogenetic analysis, mating type identification