CHYTRIDS AND ALGAE: I. HOSTndash;SUBSTRATE RANGE, AND MORPHOLOGICAL VARIATION OF SPECIES OF RHIZOPHYDIUM

摘要

Studies of pathogenicity and of morphological variation were made with pure cultures ofRhizophydium sphaerocarpumisolated fromSpirogyraand ofR. karlingiiisolated fromUlothrix. R. sphaerocarpumwas parasitic, virtually confined to species ofSpirogyraamongst which there was a wide range of susceptibility.R. karlingiigrew only on non-living algae and on pine pollen. The rhizoidal system ofR. sphaerocarpumwas quite variable in the extent of its branching. Variations in sporangium size and of the forms of the endobiotic portion of the thallus inR. karlingiigrown on different substrates were observed. Such variations have been used in the past as the basis for creation of new taxa. Pathogenicity tests with Paterson's strain ofR. sphaerocarpumconfirmed that it is saprophytic on many algae and on pine pollen in contrast with the strain isolated fromSpirogyra.