Nutrition and Parasitism of Melanospora zamiae

Abstract

M. zamiae was shown to be a biotrophic contact mycoparasite. It produced hook-shaped branches when contact was made with host hyphae. The hook-shaped branches completely or partially surrounded the host hyphae but did not invade the host cell. The parasite was able to obtain all nutrients necessary for growth and sporulation from washed living mycelia of host fungi separated from the culture medium. The required nutrients were held within the host mycelium and were not excreted into the culture medium. The host range included 11 spp. [Ceratocystis fagacearum, C. ulmi, Cladosporium sp., Diplodia zeae, Fusarium oxysporum f. lycopersici, F. sp., F. roseum, sphaeropsis malorum, Tritirachium sp., Verticillium albo-atrum and V. dahliae] of Ascomycetes and Deuteromycetes. M. zamiae was deficient for thiamine and biotin but not the growth factor mycotrophein, which it synthesized. The addition of Zn to a glucose 10-casein hydrolysate 2 liquid medium supplemented with thiamine and biotin was required for maximum axenic growth and sporulation. D-glucose, D-fructose, D-mannose and cellobiose were the best sources of C. The N sources casein hydrolysate, L-asparagine, L-aspartic acid, L-alanine, L-glutamic acid and urea were utilized to the greatest degree.