Herbicide tolerance in primitive diploid potato species comprising superseries Stellata: Toward establishment of seedling cultivation conditions for field evaluations

Wild potato species are rich sources of genes for improvement of cultivated potato. The potato taxon superseries Stellata consists of 22 primitive diploid 1EBN and 2EBN species. Many of these wild potato species are documented sources of resistance to biotic and abiotic stresses. Identification and characterization of useful genes in these species often require field evaluations, yet little has been reported on the cultivation of these materials. In this two-year study, the tolerance of seedlings of ten primitive potato species to two commonly used broadleaf herbicides, linuron and metribuzin, is evaluated. Each of the species is represented by four populations, and a total of five herbicide treatments are employed. Comparison of visual ratings and aboveground biomass fresh weights revealed variable responses to herbicide treatments. On average, metribuzin treatment reduced biomass accumulation and seedling survival more than did linuron treatment. Only Solanum pinnatisectum was tolerant of both linuron and metribuzin. Solanum cardiophyllum, Solanum jamesii, and Solanum trifidum may be segregating for tolerance to linuron. Species grouped into a common series based on morphological and molecular data do not necessarily respond to herbicide treatment in the same manner.