strains of Metarhizium were cultivated in submerged culture. The results indicated that the submerged conidia could be produced by means of microcyclic sporogenesis for some strains of Metarhizium, but perhaps , the occurrence of microcyclic sporogenesis depended on the nature of strains. Submerged sporulation of M337 strain was emphatically observed in the media containing different nutrient elements. The results showed that the submerged sporulation depended on a delicate equilibrium in the composition of the medium. Various carbon and nitrogen sources affected the production of submerged conidia greatly. Sucrose, soluble starch and lactose were effective for sporulation of submerged conidia. Peanut cake powder, yeast extract and peptone were ideal nitrogen sources for submerged sporulation. The influence of trace elements on submerged sporulation was most spectacular. Molybdenum was the most important element. Zinc was stimulatory. When all 6 elements (B,Cu,Fe,Mn,Mo,Zn) were added together, it yielded highest production of submerged conidia. Vitamins affected submerged sporulation significantly. VB 6+VH and compound vitamin B were more effective for producing submerged conidia. In addition, the infectivity of submerged conidia of M337 strain was tested in laboratory, which showed higher virulent to the 3rd～4th instar larvae of Dendrolimus punctatus. From experiment results, we can appreciate the fact of worth while making a thorough study on production of conidia of Metarhizium cultivated in submerse fermentation.
strains of Metarrhizium anisopliae and Metarrhizium guizhouense were cultivated in submerged culture with magnetized water, and the biomagnetic effects of magnetized water on submerged sporulation of Metarrhizium anisopliae and Metarrhizium guizhouense were preliminarily studied. The results indicated that the magnetized water affected the production of submerged conidia. The output of submerged conidia were increased significantly in proper magnetized water medium. In addition, the infectivity of submerged conidia of M337 strain was tested in laboratory. The test showed that there were no significant differences in the toxicity to the 3rd～4th instar larvae of Dendrolimus punctatus between Submerged conidia harvested from medium of magnetized water and those from medium of non\|magnetized water. It is hoped that the results may be used as the basis for the study on large scale of submerged conidia of Metarrhizium anisopliae and Metarrhizium guizhouense cultivated by magnetized water.
