Overwintering assessment of camelina (Camelina sativa) cultivars and congeneric species in the northeastern US

Abstract

Recent breeding and genetic engineering of the oilseed crop camelina [Camelina sativa (L.) Crantz] has raised concerns because the crop species and several congenerics are already weeds in North America. To better understand Camelina species weed risk, a two-year field experiment was conducted with six C. sativa cultivars, a wild C. sativa line, five congenic species, and two winter annual weeds in the Brassica family. The goal was to test the effect of fall seeding date on seed emergence, seed dormancy, plant establishment, winter survival, and spring flowering date. All of the C. sativa cultivars and Camelina species functioned as winter annuals and survived soil temperatures as low as -23.3 °C. Of the cultivars tested, ‘Calena’ had the highest percent winter survival. Seeds of C. sativa, Camelina alyssum (PI650132), and Camelina microcarpa (633190) showed no dormancy in the soil and germinated immediately. Seeds of Camelina rumelica (650138), Camelina laxa (Ames32859), and Camelina hispida (PI650133) partly showed dormancy surviving the winter with 0.3–1% seed emergence in the spring. All taxa overlapped in their spring flowering dates suggesting potential for pollen-mediated gene flow. Viable seeds were produced by all taxa except in C. hispida. These results suggest that weedy Camelina populations can persist as winter annuals in the northeastern United States. The new information on Camelina overwintering, seedbanks and flowering synchrony will help to lay fundamental basis for assessment of risks associated with gene flow from genetically engineered cultivars of C. sativa to Camelina species and contribute to ecological risk assessments, biocontainment for experimental field trails, and weed management.