Transmission of Barley Yellow Dwarf Virus Strains from Northwestern China by Four Aphid Species. Q. F. Zhang, Plant Virus Research Laboratory, Plant Protection Institute, Shaanxi Academy of Agricultural Sciences, Wugong, Shaanxi Province, People's Republic of China. W. N. Guan, Z. Y. Ren, and X. S. Zhu, Plant Virus Research Laboratory, Plant Protection Institute, Shaanxi Academy of Agricultural Sciences, Wugong, Shaanxi Province, People's Republic of China, and J. H. Tsai, Agricultural Research and Education Center, University of Florida, Fort Lauderdale 33314. Plant Dis. 67:895-899. Accepted for publication 28 January 1983. Copyright 1983 American Phytopathological Society. DOI: 10.1094/PD-67-895.

During a 3-yr period, 66 barley yellow dwarf virus (BYDV)-infected wheat plants were collected from 17 localities in Shanxi, Shaanxi, Gansu, and Henan provinces of the People's Republic of China. Four strains of BYDV (GPV, DAV, RPV, and GPDAV) were identified on the basis of differential aphid transmissions. The predominant strain was GPV, which was found in 77.3% of the 66 samples tested. GPV was transmitted nonspecifically by Schizaphis graminum and Rhopalosiphum padi, but transmission by S. graminum was 36.8% more efficient than by R. padi. Macrosiphum avenae rarely transmitted GPV. This strain was not transmitted by Acyrthosiphon dirhodum. DAV was found in 15.2% of the total 66 samples. DAV was transmitted nonspecifically by S. graminum, M. avenae, and A. dirhodum but was not transmitted by R. padi. RPV was found in 4.5% of the samples, RPV was transmitted exclusively by R. padi, and GPDAV was found in 3% of the samples. This strain was transmitted nonspecifically by all four aphid species. The vector specificity of GPV and DAV remained constant regardless of the number of aphids used in the tests. S. graminum and M. avenae apparently acquired and inoculated GPV and DAV strains, respectively, in as short a time as 1 min. Increase in duration of acquisition and inoculation feeding time did not appreciably increase the rate of transmission. Both nymphs and adults of S. graminum and M. avenae were efficient transmitters of BYDV. The median latent period (LP₅₀) values in both vector species were about the same. The mean retention period of BYDV was 20.1 days in S. graminum and 13.9 days in M. avenae. There were significant differences in varietal reaction to GPV and DAV among the 24 wheat cultivars tested, ranging from 0.0 to 85.7% infection.

Keyword(s): luteoviruses.