植物真菌学-lecture 1.ppt

植物真菌学Mycology Lecture 1 Overview of the Fungi What is a fungus? A eukaryotic, heterotrophic organism devoid of chlorophyll that obtains its nutrients by absorption, and reproduces by spores. The primary carbohydrate storage product of fungi is glycogen (糖原). Most fungi have a thallus composed of hyphae (sing. hypha) that elongate by tip growth Why study fungi? Fungi are among the most diverse organisms on Earth, and are considered only second to the Insects in species diversity. Fungi are ancient Major fungal lineages are ancient, perhaps emerging one billion years ago Fungi were present before the emergence of animals and vascular plants Associations Fungi are involved in symbiotic(共生的) relationships with a number of organisms Lichens (地衣） Mycorrhizas （菌根） Endophytes （植物内生菌） Mutualists （依生生物） Decomposers As saprotrophs, particularly as decomposers（分解者）, fungi are essential components of the carbon cycle and are among the few organisms that can break down lignin（木质素） Pathogens Fungi are important as pathogens of animals and plants. Over 70% of all plant diseases are caused by fungi（Irish potato famine caused by the fungus Phytophthora infestans） Skin，respiratory system disease 癣、灰指甲 Economics Industry Food industry Brewing and baking, commercial cultivation, cheese, tempeh(印尼豆豉), food spoilage, mycotoxins Industrial Organic acids: citric acid for soft drinks Medicine Antibiotics: Penicillin, griseofulvin（灰黄霉素）, cyclosporin（环孢子菌素）, etc. vitamins、Chinese medicine Enzymes Pectic enzymes, hemicellulase, etc. Classification Whittaker (1969) proposed 5 kingdoms: Prokaryotes (Monera原核生物界） Animals Plants Fungi Protista（原生生物界） Fungi versus fungi The small case “fungus” is used inclusively for a heterogenous group of organisms that have traditionally been studied by mycologists. “Fungi” refers to the organisms in the Kingdom Fungi, the true fungi, also called the “Eumycota” Kingdom Fungi Phyla: Chytridiomycota（壶菌门）