Physio-Biochemical and Yield Responses of Two Contrasting Camelina sativa Breeding Lines under Drought Stress

As a major abiotic stress, drought seriously limits global crop productivity. Limited water resources, rising populations and an increased demand for edible oils, necessitates the evaluation and commercial-scale introduction of drought-resilient alternative oil seed crops like camelina (Camelina sativa L.). Therefore, this study was conducted in a rain-exclusion structure to evaluate the effects of drought stress on water relations, antioxidant activity, seed yield and fatty acid profile of a drought-tolerant (line 7126) and drought-sensitive camelina breeding (8046) lines. These were grown at 80, 60 and 40% water holding capacity (WHC) levels in sand-filled plastic pots, with a 100% WHC treatment serving as a control. The highest decrease in leaf water relations, photosynthetic pigments, yield, oil content, stearic acid, linolenic acid and erucic acid contents was observed at 40% WHC level for the drought-sensitive breeding line. However, significant (P <= 0.05) increases in antioxidant activity, seed protein, palmitic acid, oleic acid and linoleic acid content were noted under drought stress treatments, with a maximum increase at 40% WHC in for the drought-tolerant breeding line. With good tissue water retention, better photosynthetic performance and enhanced antioxidant activity, the drought-tolerant breeding line showed greater drought resilience than the drought-susceptible breeding line, and ultimately better yield and oil quality. In conclusion, the physiological and biochemical basis of drought tolerance in camelina breeding lines should be utilized to develop novel camelina cultivars with improved drought tolerance in future. Moreover, the drought tolerant camelina breeding line (7126) should be further investigated under different field conditions and ecological zones to evaluate its adaptation potential. (C) 2019 Friends Science Publishers