|Title||Observations on chytridiaceous parasites of phanerogams. XV. Host range and species concept studies in Physoderma|
|Publication Type||Journal Article|
|Year of Publication||1964|
|Authors||Jr. FKSparrow, Griffin JE|
|Journal||Archiv fur Mikrobiologie|
1. A Physoderma on Agropyron repens, common quack grass, infects in the laboratory all other congeneric hosts used. 2. Within the Tribe Hordeae, to which Agropyron belongs, representatives of nine genera support growth of some phase of the fungus. The roseaceous host Potentilla anserina is also infected. Other plants associated in the field with infected Agropyron and known to harbor Physoderma are not susceptible to it. 3. Statistical study of resting spore size of the same Physoderma on different gramineous hosts indicates there are significant size differences on these as well as on seedlings when compared with mature plants. These size differences are greater than those utilized by some investigators in distinguishing supposed new species. 4. Host reaction differences seem more a function of the host and not of the fungus in this study. 5. Two specific published examples of supposedly different species are analyzed in the light of findings from the Agropyron parasite and are shown to be inadequate in the criteria used to distinguish them.