VIEW ARTICLE

Comparative Effects of Monochromatic Radiation on the Germination of Oospores of Three Phytophthora spp.. O. K. Ribeiro, Postgraduate Research Associate, Department of Plant Pathology, University of California, Riverside, California 92502; G. A. Zentmyer(2), and D. C. Erwin(3). (2)(3)Professors of Plant Pathology, respectively, Department of Plant Pathology, University of California, Riverside, California 92502. Phytopathology 65:904-907. Accepted for publication 20 March 1975. DOI: 10.1094/Phyto-65-904.

A simple light apparatus was used to determine the effects of the regime and quality of light on oospore germination of P. cinnamomi, P. megasperma var. sojae (races 1 and 2), and P. capsici. A combination of light filters and aqueous salt solutions was used to obtain wavelengths with peaks at 450 nm, 545 nm, 650 nm, and 750 nm. Four light regimes were tested at a light intensity of 2.0 µW cm^–2, and one light regime at 0.1 µW cm^–2. Oospore germination was stimulated under the blue and far-red filters, regardless of the light regime. This system may offer a method for obtaining consistent germination of oospores in genetical studies of these species.