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ARS Home » Pacific West Area » Pullman, Washington » Plant Germplasm Introduction and Testing Research » Research » Publications at this Location » Publication #336667
Title: Three faba bean (Vicia faba L.) breeding lines appear naturally resistant to Pythium damping-off

Author
item Hu, Jinguo
item Chen, Weidong
item McGee, Rebecca

Submitted to: Plant Disease Management Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/5/2017
Publication Date: 1/9/2017
Citation: Hu, J., Chen, W., McGee, R.J. 2017. Three faba bean (Vicia faba L.) breeding lines appear naturally resistant to Pythium damping-off. Plant Disease Management Reports. 11:V008.

Interpretive Summary: Faba bean (Vicia faba L.) is an important pulse crop grown worldwide. Several Pythium species are important soilborne pathogens that cause seed rot and pre-emergence damping-off of chickpea in the Pacific Northwest and other regions. To ascertain the reaction of faba bean (Vicia faba L.) to Pythium, we carried out a replicated experiment in a field that is naturally infested with Pythium at the Washington State University Spillman Agronomy Research Farm during the 2016 crop season. Evaluated were three advanced faba bean breeding lines derived from a cross made in Pullman, WA in 2010. The untreaded faba bean seeds germinated well with an average 86.5% of germination in the Pythium-infested experimental site where the untreated chickpea had zero germination. This preliminary observation suggested that faba bean can be an alternative crop for growers to plant in Pythium infested fields.

Technical Abstract: Pythium is a genus of common parasitic oomycetes. Several Pythium species are important soilborne pathogens that cause seed rot and pre-emergence damping-off of chickpea in the Pacific Northwest and other regions. A very reliable and effective management of Pythium damping-off of large seeded chickpea is metalaxyl seed treatment. However, mutant strains of Pythium resistant to metalaxyl have been isolated from chickpea fields in the Palouse region in 2014 and 2015. Growers are advised to delay planting (Pythium is not a problem in warmer conditions), plant alternative crops that are resistant to Pythium, such as small-seeded Desi-type chickpeas or peas, or use a different fungicide that is effective against the metalaxyl-resistant Pythium. In order to ascertain the reaction of faba bean (Vicia faba L.) to Pythium, we carried out a replicated experiment in a field that is naturally infested with Pythium at the Washington State University Spillman Agronomy Research Farm during the 2016 crop season. Evaluated were three advanced F8 breeding lines, derived from a single cross between a non-winter hardy vegetable type variety ‘Extra Precoce Violette’ and one of the most winter hardy genotypes ‘Hiverna/2-5EP1’ from Germany. The experimental plots were planted on May 12, 2016 in a randomized complete block design with four replications and a plot size of 6 ft x 5.5 ft with eight rows of plants. Each plot was planted with 50 untreated seeds.The germination percentage was calculated from stand counts on June 28, 2016, 46 days after planting. The germination percentage averaged 86.5% with a range from 80 to 92% among the plots. As for individual breeding lines, two lines with beige seed coats had a slightly higher (both 87.5%) germination percentage than the line with purple seed coat (84.5%). However, this difference is not statistically significant. It seems that faba bean can be an alternative crop for growers to plant in Pythium infested fields.