Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: May 15, 1995
Publication Date: N/A
Technical Abstract: An alfalfa synthetic (W45) has been developed which, under growth chamber and field conditions, exhibits resistance to alfalfa mosaic virus (AlMV). Field plots of W45 in Oregon and Washington were sampled for natural infection of AlMV. Virus incidence was compared with five commercially available alfalfa cultivars and synthetics during 2-year and 5-year field trials. Fifteen percent of W45 was infected after a 5-year field trial in 1992 while the infection rate in commercial varieties ranged from 69% to 81%. Six isolates of AlMV collected from different areas of North America were used to inoculate test plants in growth chamber experiments. The mean infection rate of all isolates was 31.6% for W45 in contrast with 87.5% and 83.2% for cultivars DuPuits and Vernal, respectively. Variables examined for the inoculation technique included pre-inoculation dark period on plants and use of purified AlMV. This is the first known alfalfa synthetic with resistance to geographically diverse populations of AlMV.