|Bonman, John - Mike|
Submitted to: Plant Disease
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/1/2011
Publication Date: 2/7/2011
Citation: Adhikari, T.B., Hansen, J.M., Gurung, S., Bonman, J.M. 2011. Identification of New Sources of Resistance to Xanthomonas translucens pv. undulosa in Winter Wheat. Plant Disease. PDIS-10-10-0760-RE.R2. Interpretive Summary: Bacterial leaf streak disease of wheat is becoming an important problem in US wheat production, especially in the upper Midwest. We screened winter accessions from the USDA-ARS National Small Grains Collection and discovered wheats with resistance to this disease. The resistant genes from these accessions can be incorporated into high-yielding, adapted cultivars by plant breeders to help growers manage this emerging disease problem.
Technical Abstract: : Bacterial leaf streak (BLS) caused by Xanthomonas translucens pv. undulosa, has emerged as an important disease of wheat in the United States. Planting resistant varieties offers the best strategy to manage BLS in the absence of effective bactericides. However, most of the wheat varieties currently grown in the Upper Midwest appeared to be susceptible to BLS. From the core subset of the USDA National Small Grain Collection (NSGC), a set of 415 winter wheat accessions of diverse origin and improvement status were inoculated with a virulent isolate BLSW16 of X. t. pv. undulosa at the flag leaf stage in a greenhouse. Disease reactions were assessed 10 days after inoculation using a 0 to 6 rating scale, where < 2.0 was considered as resistant and > 2.0 was regarded as susceptible. Data from the Germplasm Resources Information Network (GRIN) were used to determine if BLS resistance was associated with the geographic origin of accessions or their agronomic characteristics. A total of 42 resistant accessions (11% of those tested) were identified and no significant association between agronomic traits and resistance or between improvement status and resistance was observed. However, resistance varied with geographic origin and was significantly (P = 0.05) more frequent in accessions from Australia-New Zealand, Western Asia, South-central Asia and North America, compared to accessions from Northern and Eastern Europe. Many of the BLS-resistant accessions were also resistant to at last one other important wheat disease based on GRIN data. These diverse and novel sources of resistance to BLS can be utilized in winter wheat improvement programs.