Skip to main content
ARS Home » Pacific West Area » Salinas, California » Crop Improvement and Protection Research » Research » Publications at this Location » Publication #408974
Research Project: Genetic Improvement of Lettuce, Spinach, Celery, Melon, and Related Species

Location: Crop Improvement and Protection Research

Title: Differential sources of resistance from Lactuca serriola against three races of Xanthomonas hortorum pv. vitians causing bacterial leaf spot of lettuce

Author
item SANDOYA, GERMAN - University Of Florida
item TRENT, MARK - Former ARS Employee
item Hayes, Ryan
item LEBEDA, ALES - Palacky University
item ROSENTHAL, EMMA - Pennsylvania State University
item Simko, Ivan
item BULL, CAROLEE - Pennsylvania State University

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/26/2024
Publication Date: 3/29/2025
Citation: Sandoya, G.V., Trent, M., Hayes, R.J., Lebeda, A., Rosenthal, E., Simko, I., Bull, C.T. 2025. Differential sources of resistance from Lactuca serriola against three races of Xanthomonas hortorum pv. vitians causing bacterial leaf spot of lettuce. Plant Disease. 109(3):615-622. https://doi.org/10.1094/PDIS-06-24-1239-RE.
DOI: https://doi.org/10.1094/PDIS-06-24-1239-RE

Interpretive Summary: Cultivated lettuce is susceptible to many diseases that diminish crop yield and quality, including bacterial leaf spot (BLS) disease caused by the bacterium Xanthomonas hortorum pv. vitians (Xhv). BLS symptoms typically manifest on leaves as angular black water-soaked lesions that may later coalesce to bigger necrotic areas. Xhv causes sporadic outbreaks of BLS that translate into economic losses to lettuce producers. We have performed an extensive screening of ˜500 accessions from eight Lactuca species for their reaction to BLS. Sources of resistance to BLS races 1, 2, and 3 were identified in L. serriola, a wild-type lettuce that can be incorporated into breeding programs to develop lettuce breeding lines resistant to BLS.

Technical Abstract: Bacterial leaf spot (BLS) of lettuce (Lactuca sativa L.) caused by the bacterium Xanthomonas hortorum pv. vitians (Xhv). Xhv is hypothesized to have at least three races of the pathogen present in North America. Though resistance to Xhv race 1 has been identified in cultivated lettuce, numerous Xhv strains cause disease on cultivars carrying this resistance locus. Thus far, resistance to these ‘additional’ Xhv races have not been adequately described in L. sativa or in any other wild Lactuca species sexually compatible with cultivated lettuce. We have performed an extensive screening of ˜500 Lactuca accessions from L. sativa, L. serriola, L. saligna, L. virosa, L. aculeata, L. altaica, L. sativa var. augustana, L. livida and L. perennis species to identify accessions resistant to these ‘additional’ Xhv races. Following the initial screening, the greenhouse test confirmed that Xhv race 2 and race 3 could be defined using L. serriola accessions. Race 2 strain BS3217 was avirulent on ten L. serriola accessions including PI 491114 and its selections, while race 1 (BS0347) and race 3 (BS2861) strains of Xhv were virulent on these genotypes. L. serriola accession ARM09-161-10-1-4 was the only genotype resistant to the race 3 strain BS2861. L. serriola accessions identified in this study to be resistant to race 2 and race 3 of Xhv, together with race 1 resistant cultivars, can be used for pyramiding resistance loci against the three races of the BLS-causing pathogen.