Combined use of seaweed extract and arbuscular mycorrhizal fungi for alleviating salt stress in bell pepper (Capsicum annuum L.)

Abstract

Salinity is the most catastrophic abiotic stress that aggravating its detrimental effects on productivity of horticultural crop especially bell pepper that might be alleviated through judicious application of seaweed extract (SWE) and arbuscular mycorrhizal fungi (AMF). Therefore, the present study was focused on the interactive effects of SWE and AMF to improve growth, physiological responses and yield performance of bell pepper grown under salt stress. Factorial experiment consisted of three factors namely SWE dose (non-treated control, 2.5 g L–1, 5.0 g L–1 and 7.5 g L–1 designated as SWE0, SWE2.5, SWE5.0 and SWE7.5, respectively); water salinity levels (control- 0.54, 4, 8 and 12 dS m–1) and two levels of AMF inoculation (with AMF [+AMF] and without AMF [–AMF]). Factorial experiment was laid out where treatment combinations were assigned completely randomized design (CRD) with three replications. SWE treated plants upgraded leaf relative water content, leaf greenness and membrane stability index 16 %, 19 % and 13 %, respectively with lower electrolyte leakage (15 %) at 12 dS m–1 water salinity compared to non-treated plants. In addition, higher proline content (79 %) was observed at SWE5.0 in AMF inoculated plants over control (non-inoculated plants. Marketable fruit yields were higher (31 %) with the combined application of SWE and AMF at extreme salt stress conditions (12 dS m–1). Apart from that, SWE7.5 treated plants exhibited more accumulation of potassium (26 %) and phosphorous (32 %) while less accumulation of sodium (16 %) was displayed at higher salinity level (12 dS m–1) compared to control plants. Moreover, SWE and AMF treated plants showed better postharvest quality (pH, Brix) performance during storage condition compared with control. Taken together, it might be inferred that integrated application of SWE and AMF had boosted up morpho-physiological traits, yield and ion homeostasis to ameliorate the baleful effects of salt stress on bell pepper.