Location: Crop Improvement and Protection ResearchTitle: Characterization of Verticillium dahliae disease reactions in lettuce differential cultivars Author
|Short, Dylan - University Of California|
|Puri, Krishna - University Of California|
|Sandoya, German - University Of Florida|
|Subbarao, Krishna - University Of California|
Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 3/24/2017
Publication Date: 8/8/2017
Citation: Short, D.P.G., Puri, K., Sandoya, G.V., Simko, I., Hayes, R.J., Subbarao, K.V. 2017. Characterization of Verticillium dahliae disease reactions in lettuce differential cultivars. American Phytopathological Society Annual Meeting, August 5-9, 2017, San Antonio, Texas.
Technical Abstract: Soilborne diseases significantly affect high value crops in coastal California, including lettuce and strawberry. Breeding crops for pathogen resistance is a strategy for the sustainable management of crop disease. Verticillium dahliae is a soilborne fungus that causes wilt and economic losses in a broad range of hosts. Homologs of a conserved plant locus that confers resistance to Verticillium infection were first identified in tomato and are now known to occur widely in plants. In lettuce, a dominant allele of the locus Vr1 confers resistance to race 1 isolates of V. dahliae, which are defined by the fungal avirulence gene Avr1. Currently, only partial resistance in lettuce to V. dahliae race 2 is available in a few plant introductions (PIs). Pathogenicity tests involving rootstocks of tomato differentials have led to the identification of race 3 among isolates that previously belonged to race 2. Experiments involving several lettuce cultivars and V. dahliae isolates and cultivars revealed diverse reactions that point to the potential of putative race 3 differentials among lettuce cultivars. Results of greenhouse experiments confirming the pathogenicity and virulence of a diverse panel of V. dahliae tested with race 1-resistant and race 2-partially resistant PIs will be presented, as well as the status of allelism tests to determine the nature of putative race 2 resistance in lettuce.