Study On ⁶⁰Co Mutation Breeding Of Volvariella Volvacea

The Volvaria volvacea strain PY for usual use, its haploid offsprings PYd15, PYd21 and the crossed strain PYd15×PYd21 were used as the material in this study. The strains were put under Co60-γray for mutation and the radiation dose were set for 1.00KGy, 1.25KGy, 1.50KGy, 1.75KGy, 2.00KGy, 2.50KGy. However, none of the strains reached the fatal dose under the condition. PY is the least radio resistant strain and the fatal rate was more than 50% when the radiation dose was 2.00KGy. The survival rate of PYd15 was 50% when the radiation dose was 2.50KGy. None of the radiation caused PYd15×PYd21 and PYd21 to die at the rate of more than 50%.19 mutation strains from PY, 57 mutation strains from PYd15×PYd21 and 42 mutation strains from PYd15 and PYd21 were selected after preliminary screening. 14 crossed strains were obtained after the mutation strains from PYd15 crossed with PYd21 and the mutation strains from PYd21 crossed with PYd15. All the crossed strains and the mutation strains from PY and PYd15×PYd21 were grown in the mushroom farm.After grown in the mushroom factory, 14 strains were selected based on the economical traits such as product, the shape and color of the fruit body. The number of them are 14-2, 17-2, 18-1, 3-7, 5-2, 7-7, 7-3×PYd21, 10-3×PYd21, PY1-3, PY1-5, PY3-2, PY5-1, PY5-2, PY5-14 and the economical traits of 14-2 and 18-1 were better than others. However, the fruit body color of 18-1 was darker than 14-2.Tested by means of antagonism test, analyzing of the grow rate of mycelium in PDA medium, biological characteristics observation, colonial morphology comparison, molecular biology test and exoenzyme activity measurement with the control strains PY, PYd15×PYd21, PYd15, PYd21 , 14 strains were demonstrated to be the mutants from original strains. Compared with PYd15, the haploid strains 7-3 and 10-3 changed in the genetic material and phenotype. The genetic material of crossed strains 7-3×PYd21 and 10-3×PYd21 were different with PYd15×PYd21. The traits of the former were better than the latter. However, whether the traits of the 14 strains could be inherited by the offsprings still need to be tested in future.