Abstract
Considering the burning issue the present study was undertaken in pot culture at the Cholistan Institute of Desert Studies (CIDS), The Islamia University of Bahawalpur, Pakistan for enhancing drought tolerance in two oilseed crops (OC) crops camelina (Camelina sativa L.) and canola (Canola napus L.) through improving physiological, biochemical, and antioxidants activity by foliar application of selenium (Se) under drought stress. Two Camelina (i.e., 'Australian Camelina' and 'Canadian Camelina') and canola genotypes (i.e., `AARI Canola' and `UAF Canola') were used as plant materials during the growing season of 2016. Both Camelina and Canola genotypes were grown under normal (100% FC) and water deficit (drought stress) (40% FC) conditions. Four levels of Se: such as seeds priming with 75 mu M Se, foliar application of Se at 7.06 mu M and foliar Se in combination with seeds priming (7.06 mu M & 75 mu M) along with control were applied at the vegetative stage of both OC crops for screening drought tolerant genotypes. All treatments were arranged three times in a randomized complete block design. Both OC crops were grown upto the maturity and data on physiochemical, antioxidants and yield components were recorded during this study. Results of the present study indicated that the physio-biochemical parameters such as WP (water potential), OP (osmotic potential), TP (turgor pressure), proline, TSS (total soluble sugar), TFAA (total free amino acids), TPr (total proteins) and TS (total sugars); and total chlorophyll contents were improved by foliar application Se along with seed priming by Se in both OC crops in both drought stress and non -stress (control) conditions. Similarly, osmoprotectants such as GB (Glycinebetaine), anthocyanin, TPC (total phenolic contents) and flavonoids; as well as antioxidants such as APX (ascorbate peroxidase), SOD (superoxide dismutase), POD (peroxidase) and CAT (catalase) were also showed better enhancement in both OC crops through foliar application in combination with seed priming with Se (7.06 mu M & 75 mu M) under normal as well as water deficit (drought) conditions. Yield and its components i.e., branches plant(-1) (no.), 1000 -seed weight (g), seed and biological yield (t ha(-1)) of both OC crops were increased through foliar application in combination with seed priming by Se (7.06 mu M & 75 mu M) under drought and non-drought stress conditions. Both camelina and Canola genotypes categorized based on all the above-mentioned parameters under the water deficit (drought stress) condition and foliar application of Se, the genotype 'Canadian Camelina' maintained the highest values for all these attributes. Therefore, it is revealed that foliar application in combination with seed priming by Se helps to improve drought tolerance of OC crops and also leads to an increase in the productivity of crops under drought stress. Among the genotypes, 'Canadian Camelina' performed the best when seeds of the genotypes were primed with Se in combination with foliar application of Se at the vegetative stage.