Comparison of host ranges of Peronosclerospora philippinensis and P. sacchari.
In a study to determine additional hosts for overwintering of P. philippinensis which would act as reservoirs of inoculum for maize 72 plant spp. representing 22 genera within 8 tribes of the Gramineae were tested for susceptibility to systemic colonization after conidial inoculation with 2 isolates from the Philippines. All susceptible spp. were members of the tribes Andropogoneae (Andropogon, Bothriochloa, Eulalia, Saccharum, Schizachyrium and Sorghum) or Maydeae (Tripsacum and Zea). Not all accessions susceptible to 1 isolate of the pathogen showed systemic symptoms when inoculated with the 2nd isolate; in some instances only a few plants of an accession developed systemic symptoms. The results were remarkably similar to the previous host range study with P. sacchari from sugarcane in Taiwan, and the information presented indicates a very close phylogenetic relationship between P. sacchari and P. philippinensis.