Eucaryotic microorganisms

a. An estimate of the total number of eucaryotic micro-organisms species in China

There are three groups of eucaryotic micro-organisms, i. e., myxomycetes, fungi, and oomycetes.

Based on studies in Britain, Finland and Switzerland, the ratio between the number of known species of fungi and vascular plants is between 4:1 and 6:1 (Hawksworth, 1991). Extrapolating, using the ratio of 6:1, the 30,000 vascular plants in China should yield an estimated 180,000 species of fungi, or about 15% of the world total. More than 600 new species were identified from 1982 to 1994 in China, (each year the average is 50, and this is only 2% of the world’s annual average of 1,700 species from 1986 to 1990). Additionally, 1,100 new records (the average is 92 records per year) were reported from China between 1982～1994. At the current rate of 150 additional species (new species and new records) per year, it will take 1,300 years for China to complete its inventory of the total species.

b. Number of known eucaryotic micro-organisms in China

More than 10,000 species of myxomycetes, fungi, and oomycetes have been reported upon China, but many of these are expected to be unnecessary synonyms. Actually, it seems reasonable to recognize that the number of acceptable species might be 8,000 or more, that is, about 4% of the total estimate of species and 11% of the world’s total known species (about 70,000 species), of which 260 species belong to the Gymnomycota, 7,500 to the Eumycota and 300 to the Oomycota.

c. Biodiversity of eucaryotic micro-organisms in China

More than about half of the 100 orders of known eucaryotic micro-organisms are at present almost entirely unknown in China. In fact, of about the twenty orders which have been studied, most are still inadequately known and only involve several families and genera. The marine fungi of the vast territorial seas of this country have been virtually uninvestigated. Only a few reports on marine yeasts have been made in recent years. Records of freshwater fungi are few and scattered in a small literature on the Oomyceta (mainly Saprolegnia and Pythium). The studies on aquatic hyphomycetes are at an initial stage, and only about 50 species have been recorded (200 species are known in the world). Entomogenous fungi have recently been studied actively in China, and about 180 species have been recorded up to now (totally 900 species are known in the world). Soil fungi are inadequately known. Perhaps only Aspergillus (89 known species) and Penicillium (70 species, whereas there are 96 in the world) are comparatively well-studied in China. The known number of ecotomycorrhizal fungi is 642 species in 68 genera and 29 families. Of these, 612 species in 59 genera and 22 families are basidiomycetes, and 30 species in 9 genera and 7 families are ascomycetes. Only 40 species of endomycorrhizal fungi have been identified in recent years. Hypogeous fungi having subterranean sporocarps, including the truffles and other ascomycetes, are of high economic importance. Only 60 species of the 1,000 known ones have been recognized in China. Endophytic fungi, parasites and symbionts of the Arachnida, Myriapoda, Crustacea, aquatic insects and marine plankton, as well as fungi in the rumen of herbivorous mammals, are almost unknown.