ARS | Publication request: Evidence that QTL may be involved in a tolerance response to Pea enation mosaic virus in pea (Pisum sativum L.)

Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: May 15, 2009
Publication Date: June 15, 2009
Citation: Larsen, R.C., Porter, L., Mcphee, K. 2009. Evidence that QTL may be involved in a tolerance response to Pea enation mosaic virus in pea (Pisum sativum L.). Phytopathology. 99:S69.

Technical Abstract: Pea enation mosaic virus (PEMV) is a serious disease of fresh market and dry pea in the Pacific Northwest region of the U.S. The En gene confers resistance to PEMV in pea, however a limited number of available cultivars contain the gene, and sources of tolerance have not been reported. In 2007, advanced pea breeding lines were screened for resistance to PEMV in naturally infected field trials in Corvalis, OR. Lines were considered resistant based on lack of PEMV symptoms such as vein clearing and translucent flecks on leaves. Field-resistant lines were further screened for resistance in repeated greenhouse experiments by mechanical inoculation with the virus. Four symptomless field-resistant lines exhibited symptoms of PEMV under greenhouse screening conditions, but the plant growth of these lines remained robust and was not significantly different than the buffer-treated controls (BTC). These lines demonstrated tolerance to PEMV since minor proliferations or bumps were expressed on pod surfaces but pod-fill and seed size was not significantly less than the BTC. RT-PCR primers specific to the coat protein gene of PEMV were used to assess symptomatic tissue from inoculated plants. Virus titer was not different from susceptible controls on three of the four lines but was significantly less in line PS08-41. Potential new QTLs with resistance to PEMV may be present in the four breeding lines lines that can be used to develop new cultivars with tolerance to PEMV.