Link to home

Relationship Between Phyllosphere Population Sizes of Xanthomonas translucens pv. translucens and Bacterial Leaf Streak Severity on Wheat Seedlings

February 1999 , Volume 89 , Number  2
Pages  131 - 135

Kurt D. Stromberg , Linda L. Kinkel , and Kurt J. Leonard

First and second authors: Department of Plant Pathology, University of Minnesota, St. Paul 55108; and third author: USDA, ARS Cereal Disease Laboratory St. Paul, MN 55108

Go to article:
Accepted for publication 25 October 1998.

The relationship between leaf-associated population sizes of Xanthomonas translucens pv. translucens on asymptomatic leaves and subsequent bacterial leaf streak (BLS) severity was investigated. In three experiments, X. translucens pv. translucens was spray-inoculated onto 10-day-old wheat seedlings over a range of inoculum densities (104, 105, 106, 107, and 108 CFU/ml). Lesions developed most rapidly on plants inoculated with higher densities of X. translucens pv. translucens. Leaf-associated pathogen population sizes recovered 48 h after inoculation were highly predictive of BLS severity 7 days after inoculation (R2 = 0.970, P < 0.0001). The relationship between pathogen population size on leaves and subsequent BLS severity was best described by the logistic model. Leaf-associated X. translucens pv. translucens population size and BLS severity from a particular pathogen inoculum density often varied among experiments; however, the disease severity level caused by a particular leaf-associated X. translucens pv. translucens population size was not significantly different among experiments. Biological and disease control implications of the X. translucens pv. translucens population size-BLS severity relationship are discussed.

The American Phytopathological Society, 1999