14 research outputs found
Population Structure of the Bacterial Pathogen Xylella fastidiosa among Street Trees in Washington D.C.
Funding for Open Access provided by the UMD Libraries Open Access Publishing Fund.Bacterial leaf scorch, associated with the bacterial pathogen Xylella fastidiosa, is a widely
established and problematic disease of landscape ornamentals in Washington D.C. A multilocus
sequence typing analysis was performed using 10 housekeeping loci for X. fastidiosa
strains in order to better understand the epidemiology of leaf scorch disease in this municipal
environment. Samples were collected from 7 different tree species located throughout
the District of Columbia, consisting of 101 samples of symptomatic and asymptomatic foliage
from 84 different trees. Five strains of the bacteria were identified. Consistent with
prior data, these strains were host specific, with only one strain associated with members of
the red oak family, one strain associated with American elm, one strain associated with
American sycamore, and two strains associated with mulberry. Strains found for asymptomatic
foliage were the same as strains from the symptomatic foliage on individual trees.
Cross transmission of the strains was not observed at sites with multiple species of infected
trees within an approx. 25 m radius of one another. X. fastidiosa strain specificity observed
for each genus of tree suggests a highly specialized host-pathogen relationship