HEREDITARY VARIATION AND GENETIC RECOMBINATION IN KOJI-MOLDS (ASPERGILLUS ORYZAE AND ASP. SOJAE)

Abstract

(1) The constant C- and M-types which were obtained from one of the "Wild Strains" (Asp. Oryzae aX) have been subjected to ultraviolet treatment.(2) M-type mutants have been obtained from the parent C-type, and C- and X-type mutants from the parent M-type. These mutants have proved to be the same as the natural variants mentioned above (1). (3) The mutants that have been obtained from the C-type are as follows: 1. Almost-normal 2. Restricted 3. Sterile 4. Reduced nitrate 5. Heavy 6. Olive 7. Brown 8. Albino 9. Mycelial 10. Yeast 11. Maroon-exudate.The mutants that have been obtained from the M-type are as follows: 1. Almost-normal 2. Restricted 3. Sterile 4. Reduced nitrate 5. C 6. CR 7. Brown 8. Yellow 9. X(4) The conidia of the C- and M-types which are natural variants are of comparatively uniform size. Among induced mutants from the C- and M-types, the conidia of Reduced nitrate, Brown, Mycelial, and X are generally found in a great variety of sizes.(5) Thus the morphology of Koji-molds has been remarkably changed by ultraviolet irradiation except for the structure of conidial and conidiophore walls.