Agricultural Research Service (ARS) scientists are testing five new potato breeding lines with the hope of opening the door to new varieties that resist powdery scab and black dot diseases.
The fungi responsible for these diseases many times show up together in the same soil, going after the potato plant’s roots, tubers, or stems. According to ARS, outbreaks can cause yield losses of up to 25% and stop tubers from reaching the sizes needed by the industry. Of the two fungi, only black dot can be controlled with fungicides. Typically, multiple applications are needed, driving up production costs.
A more sustainable alternative is genetic resistance, according to geneticist Chuck Brown, with the ARS Vegetable and Forage Crops Production Research Laboratory in Prosser, WA. In studies conducted there since 2004, researchers screened an existing collection of wild and cultivated potatoes for sources of natural resistance to powdery scab and black dot in a local grower’s infested field.
The researchers efforts led to five advanced potato breeding lines that had been developed from a wild species from Mexico, Solanum hougasii, and a recent commercial release, Summit Russet. In three years of field trials in Washington State and Idaho, the potato breeding lines consistently showed fewer disease symptoms — root galling for powdery scab and sclerotia-infected stems for black dot — than other lines and varieties tested.
The research findings have been published in the journal Plant Disease. For more information, click here.
Source: USDA ARS