Submitted to: Journal of the American Society for Horticultural Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/22/2001
Publication Date: 1/20/2002
Citation: Ryder, E.J. 2002. Inheritance and interactions of necrotic, mottled, and resistant reactions to lettuce mosaic virus in lettuce.. Journal of the American Society for Horticultural Science. 127(2):279-283. Interpretive Summary: This paper describes two new genes for a severe reaction to lettuce mosaic virus. The plants develop areas of brown dead tissue. Lettuce mosaic is a devastating disease in lettuce and the information in this paper will be useful in helping growers avoid the most severe types of damage.
Technical Abstract: Segregation data from crosses between necrotic and mottled parents showed that a single gene controls the difference in reaction type: necrosis is dominant to mottled. Segregation data from crosses between resistant and two necrotic parents showed that two genes controlled each reaction. In crosses with the necrotic cultivar Prizehead, there were two independent genes, controlling necrotic vs. mottled and resistant vs. susceptible. In a cross with the necrotic cultivar Maikonig, resistance was epistatic to necrotic, suggesting a second necrotic allele. Crosses among necrotic cultivars indicate a single gene for the necrotic reaction, but the possibility of more than one allele. Necrotic alleles identified are named Necrotic-1m and Necrotic-1p.