One of the major field constraints to seed production in safflower has proven tobe soil born pathogens, Phytophthora drechsleri and Pythium ultimum. In order toevaluate the efficiency of a field-laboratory selection method to improve resistanceof safflower against soil born pathogens, Ph. drechsleri and P. ultimum, a two-yearinvestigation was conducted. The results showed that selection is an e...

Phytophthora ramorum, causal agent of sudden oak death, is well established over approximately 450 km of native forest along the California coast. In the course of research on this invasive exotic pathogen, two other putatively exotic aerial Phytophthora species, P. nemorosa and P. pseudosyringae, were discovered (Ivors and others 2004, Linzer and others 2006). Little is known about the ecology...

Members of the oomycete genus Phytophthora are the most devastating pathogens of dicot plants. Recent developments in the study of these organisms have led to improved understanding of their phylogenetic relationships and trends in their evolution. Molecular analyses of nonhost (species-level) resistance offer exciting prospects for disease management. A model that evokes a complex interplay of...

Phytophthora capsici from seven provinces of China were investigated for their mating type, hyphal growth, zoospore production, and virulence. All of the morphological characteristics and the results of polymerase chain reaction confirmed that these isolates were indeed Phytophthora capsici. The test of mating type showed that the mating types of 19 representative isolates from China varied. Th...

Cyclic AMP, Radioimmunoassay, Phytoalexins, Glycine max, Phytophthora megasperma cAMP levels were monitored in soybean (Glycine max) infected with race 1 of Phytophthora megasperma f. sp. glycinea and in soybean cell suspension cultures treated with a glucan elicitor from P. megasperma. While cAMP could be readily detected in soybean hypocotyls using a radio­ immunoassay, no correlation was obs...

Saprophytic growth of Phytophthora cinnamomi indicated that the pathogenicity was not enhanced by addition of Nor Ca-sources to the basal growth medium. Mycelium obtained from the N and Ca-enriched sources and used to inoculate blue lupin seedlings indicated that the pathogenicity of the fungus was reduced by the addition of either N or Ca to the fungus cultures. The detached root technique was...

A new screening method for inhibitors of cellulose biosynthesis is described. This method utilized three microbial strains; a cellulose-containing fungus Phytophthora, and a cellulose non-containing fungus Candida, and a bacterial strain of Acetobacter, a cellulose-producing acetic acid bacterium. The primary screen examined microbial cultures for selective growth inhibition against Phytophthor...