High Night Temperature Stress Interferes with Yield and Seed Quality in Canola (Brassica napus L.).

Canola (Brassica napus L.) is a major commercial oilseed crop associated with high quality oil. Being a cool season crop, it is extremely sensitive to small variation in temperature. Effect of high day time temperature has been well studied but the impact of high night temperature (HNT), which is currently increasing and predicted to further increase has not been investigated in winter canola. Hence, the effect of HNT during flowering and pod filling stages were studied in growth chamber experiment following a split-plot design. Ten canola cultivars were grown under 23/15 °C day/night temperatures with photoperiod of 16/8 h light/dark. High night (23/20 °C; 10 hours per day from 8:00 PM to 6:00 AM) temperature stress was imposed on the 7^th day of first flowering and continued until physiological maturity. During stress imposition, specific flowers opening under control and those flowering under HNT stress were marked to obtained pods having undergone HNT exposure at different developmental stages which will allow for quantifying differential impact of stress on yield and quality parameters. Oil, protein and the percentages of saturated and unsaturated fatty acids at different pod developmental stages are currently being analyzed. Additionally, the trade-off between pod yield and quality (protein and quality) under control and HNT is documented. Appropriate donor/s that can maintain yield and quality under HNT will be recommended for introducing into ongoing canola breeding programs.