Unraveling the synergistic effects of microbes and selenium in alleviating drought stress in Camelina sativa L.

Abstract

Globally, drought has emerged as one of the most serious threats to oil seed crops including Camelina production, which necessitates screening of drought resistant cultivars that are more responsive to mitigation treatments. Effect of microbes and Selenium (Se) is associated with the upregulation of available nutrients. Therefore, present study was aimed to evaluate the effect of Se interactions with arbuscular mycorrhizal fungi Rhizophagus intraradices at four different treatments (T1: CK), T2: inoculation of R. intraradices), T3: Se-priming (2 mM), T4: inoculation of R. intraradices+ Se-priming (2 mM) on two Camelina genotypes (Australian and Canadian) under varied water levels (100%, 75%, 50%, and 25% field capacity, FC). Se with Seed priming and microbes were applied through inoculation of Camelina seed. The experiment was conducted in a Completely Randomized Design (CRD) with three replications at MNS- University of Agriculture Multan, Pakistan. The results exhibited that inoculation of R. intraradices + Se-priming (2 mM) application significantly improved the physiological and growth parameters of Camelina under water stress. The application of inoculation of R. intraradices + Se-priming (2 mM) increased crop growth, physiology, and antioxidants as compared to other treatments (T1: (Control), T2: Microbes (R. intraradices), T3: Se-priming (2 mM). The application of Microbes + Se-priming (2 mM) increased the total soluble sugars by 69.6%, 23.4%, and 10.8% as compared to other treatments (T1: (Control), T2: inoculation of R. intraradices), T3: Se-priming (2 mM)., respectively, irrespective of field capacity levels. Among varied water levels, 100% FC showed unmatched results regarding crop growth traits, physiological aspects, and antioxidants activities as compared to water stressed levels of 75%, 50%, and 25% FCs. Proline contents were also increased by 93.9%, 52.5%, and 10.2% at 100% FC as compared to 25%, 50%, and 75% FCs. The response of Canadian Camelina was found better than Australian Camelina in most of the growth, physiological, and antioxidant parameters. Canadian Camelina also showed a 2.14% increase in superoxide dismutase activity as compared to Australian Camelina. The combination of Canadian Camelina inoculation of R. intraradices + Se-priming (2 mM) is recommended to achieve higher productivity under water-stressed conditions. However, long-term studies must be conducted to screen out drought resistant and inoculation of R. intraradices + Se-priming responsive genotypes for increasing Camelina yield in low input farming systems. Further, Se-mediated physiological and biochemical associated with drought tolerance in Camelina plants and future research prospects have been elucidated.