Response of Cultivars and Wild Species of Rice to Yellow Dwarf Disease. V. Muniyappa, Department of Plant Pathology, Agricultural College, Hebbal, Bangalore 560024, India. B. C. Raju, Department of Plant Pathology, University of California, Davis 95616. Plant Dis. 65:679-680. Accepted for publication 11 December 1980. Copyright 1981 American Phytopathological Society. DOI: 10.1094/PD-65-679.

Of 80 rice cultivars tested for resistance to yellow dwarf disease under field conditions, 58 showed symptoms in the main crop and 77 in the second growth (ratoon) crop. Twenty-two cultivars showed no symptoms in the main crop, and three showed no symptoms in either the main or second growth crop. Nephotettix virescens was used to transmit the agent in laboratory inoculations of 16 wild Oryza spp. O. alta, O. australiensis, O. brachyantha, O. eichingeri, O. grandiglumis, O. latifolia, O. officinalis, and O. ridleyi were resistant to yellow dwarf. None of the 42 species tested that were outside the genus Oryza became infected.