Studies On Interaction Between Grifola Umbellata And Its Companion Fungus

The interaction between Grifola umbellata (Pers.) Pilat and its companion fungus was studied by morphology, physiological biochemistry and molecular biology, including morphological characteristics of interaction between G. umbellata and companion fungus, the effects of companion fungus on some material content and related enzyme activity, and on the gene expression of G. umbellata.Studies on biological characteristics of G. umbellata and companion fungus suggested that their hyphal morphology were more closely under optical microscope, but the morphology and formative manner of their conidiophores were more differently. The external morphology of G. umbellata and companion fungus was different when they grew on the same medium or on different media, respectively. Their chemical fingerprints of their extracts were similar at 247nm, but not the same. New substances were produced after dual cultured of them. Internal transcribed spacer (ITS) of companion fungus, cultured hypha, fruit body and wild sclerotia of G. umbellata were sequenced, the results showed that the ITS of companion fungus were 628 bp, but that of hypha, fruit body and wild sclerotia of G. umbellata were all 626 bp. The similarity of their ITS sequences was up to 99.36 percent. It could be acknowledged that G. umbellata and companion fungus were of highly relative relation in molecular evolution.Morphological characteristics of hyphal interaction between Grifola umbellata and its companion fungus were investigated by external observations, light microscopy and transmission electron microscopy (TEM). External observations showed that a dense antagonism line was formed by both G. umbellata and companion fungus after their hyphae contacted each other in dual culture. Many hyphal strands emerged on the colony of G. umbellata and differentiated to sclerotia from where hyphal strands crossed. Light microscope observations revealed the process of antagonism line formation. Mature antagonism line was of structural differentiation. TEM observations showed that after colonies hyphal contact, a series of reactions always occurred in both G. umbellata and companion fungus. Cells in the center of antagonism line were dead. Cells of G. umbellata adjacent to the antagonism line were usually large and hollow, with unilateral thickened wall, whereas those of companion fungus were empty, with thin or thick wall.Structural characteristics, thick walled hyphae and crystalline formation of artificial scleroita of G.