Keele Research Repository

Two rust fungi with Caryophyllaceous hosts were studied, the carnation rust Uromyces dianthi (Pers.) Niessl and the Sweet William rust Puccinia arenariae (Schum.) Wint. Their disease symptoms were investigated.
The morphology of U. dianthi urediospores and teliospores and P. arenariae teliospores and basidiospores were examined. The surface structure of germinating U. dianthi urediospores was observed by scanning electron microscope.
Experiments to determine the optimum germination temperatures of U. dianthi urediospores and P. arenariae teliospores were carried out. The optimum pH value for the germination of U. dianthi urediospores was also determined. U. dianthi urediospore exudates were investigated for possible self-germination inhibitors and various experiments performed on the inhibitory properties of the exudates.
A successful attempt was made to initate axenic cultUres of U. dianthi from urediospores and the conditions necessary for the optimum growth of U. dianthi in vitro were determined. Various nitrogen and carbohydrate sources were compared as to their ability to support saprophytic colonies of U. dianthi. The phenomenon of axenic growth cessation was investigated. Attempts to culture P. arenariae from basidiospores were unsuccessful.
Experiments to observe the effects of systemic fungicides on U. dianthi cultures were undertaken.
The morphology of septal pores of axenic hyphae of U. dianthi were examined using a transmission electron microscope.