Evaluating genetic mechanisms and performance characteristics of alternative oilseed crops for on-farm biofuel production in Colorado

Includes bibliographical references. ; 2015 Summer. ; Dryland winter wheat (Triticum aestivum) cropping systems dominate most of the agricultural landscape in Colorado’s semi-arid eastern plains. Since this area’s climate is characterized by frequent heat and drought, it is important to maximize water use efficiency to make agricultural lands as productive as possible. Adding a spring crop in rotation with winter wheat intensifies the rotation, increasing water use efficiency by up to 37%. Recent research has explored further intensifying this rotation by adding an oilseed crop into a wheat – spring crop – fallow rotation during the fallow period. Ideally, the oilseed crop acts as a cover crop for part of the season and leaves enough time at the end of the season to regenerate water in the soil profile before planting wheat in the fall. The oil from this crop can be used to produce on-farm biofuels, offsetting petroleum diesel costs without displacing high-value food crops. Additionally, the meal from this crop acts as a value-added byproduct by providing feed for livestock. Since traditional oilseeds such as soybean (Glycine max) and rapeseed (Brassica napus) do not perform well in Colorado, several alternative oilseeds have been tested to assess whether they can fill this niche. Camelina (Camelina sativa) has shown great potential, with high oil content and inherent resistance to many biotic and abiotic stressors. Other potential oilseeds include Brassica juncea and Brassica carinata, but both of these species have exhibited longer life cycles and lower yields than camelina. A major challenge to camelina production in Colorado is a susceptibility to heat stress during reproductive periods. Both short periods of intense heat stress and longer periods of mild heat stress can cause floral and seed abortion, resulting in reduced yield. In the current study, a quantitative trait locus (QTL) approach is used to identify heat and drought tolerance mechanisms and yield components, explore the extent of pleiotropy, ...