Role of mycorrhizal fungi in improving the tolerance of melon (Cucumus melo) under two water deficit partial root drying and regulated deficit irrigation

Abstract

The present study aims to elucidate the impact of arbuscular mycorrhizal fungi (AMF) inoculation and partial root drying (PRD), or regulated deficit irrigation (RDI) techniques on the growth, physiology and biochemistry of melon plants under three water regimes: control (100% of field capacity (FC) (C100%)), 75% of FC (PRD75%) and 50% of FC (PRD50% and RDI50%). The experiment was carried out under semi-controlled greenhouse conditions and the AMF inoculum used was a field-sourced native Aoufous consortium. Obtained results show an increase in shoot dry weight in inoculated plantss under PRD75% and PRD50% by 12 and 9% respectively, compared to C100%. Mycorrhizal plants under PRD75%, PRD50% and RDI50% maintained the highest relative water content, leaf water potential (Ψleaf) and stomatal conductance, as well as photosynthetic pigments, compared to their respective control plants. In addition, PRD75%+AMF and RDI50%+AMF recorded the highest values of evapotranspiration. AMF increased total soluble sugars, proteins, and proline contents in response to PRD and RDI. Our results demonstrate that PRD75%, PRD50% and RDI50% in combination with AMF were the most effective treatments for improving growth, physiological and biochemical traits of melon under water stress.