Winter and summer annual biotypes of camelina have different morphology and seed characteristics

Abstract

Camelina [Camelina sativa (L.) Crantz] has two distinctive biotypes, summer and winter, with winter biotypes requiring a vernalization treatment to enter the reproductive phase. Increased interest in broadening the diversity of winter-hardy cover crops in the northern Great Plains of the U.S. to reduce soil erosion through the winter months has led seed companies to offer winter camelina seed outsourced from other states. Regrettably, in 2017, outsourced camelina seed from other states turned out to be summer biotypes that did not survive the North Dakota winter. The objectives of this study were to determine the morphological characteristics of seed and seedlings from summer- and winter-biotypes. Morphological characteristics of seedlings were determined by growing nineteen summer- and eleven winter-biotypes in an environmental chamber. The experimental design was a randomized complete block design with three replicates. To determine differences in seed wavelength absorbance between winter- and summer-biotypes both visible and near infrared spectra were examined, which encompass 400–2498 nm wavelengths. Mixtures of cultivars Joelle (winter) and one summer type were analyzed using near infrared spectroscopy (NIRS). Seed mixtures were prepared in increments of 5% of ‘Joelle’. Mixtures of different lots of Joelle were prepared in increments of 25%. Significant interactions were present and observed for pairs of vegetative leaves, growth stage, height, leaf length, leaf width and the number of lobes. The equation for the ratio of winter seed (r2 = 0.96) performed very well, being able to distinguish known field grown cultivars used in the equation. Differences in seed and seedling morphological characteristics can be used to differentiate winter- or summer-biotypes. Having a rapid method to determine the percentage of winter camelina in an unknown seed sample will be very favorable for all producers, as well as seed companies, interested in growing winter camelina as either a winter-hardy cover crop or as a winter annual cash crop.