Impact of arbuscular mycorrhizal fungi (AMF) and/or Baker's yeast on root rot/ wilt disease and growth parameters of date palm offshoots in New Valley Governorate, Egypt

Abstract

Root rot and wilt complex were the important diseases in offshoots and new orchards of date palm growing in different Oases in New Valley Governorate. The ability of arbuscular mycorrhizal fungi (AMF) and/or Baker's yeast (BY) individually and in combination used as soil drench to induce resistance against root rot / wilt disease complex and their effect on growth parameters, mineral and pigment contents in leaves was examined. The obtained data show that AMF and BY individually and/or in combination were able to protect offshoots against root rot /wilt disease complex compared with check treatment (control)in pots under artificial infection with Fusarium oxysporum , F. solani and F. moniliform and naturally infection under nursery conditions in both locations (El-Kharga and El-Dakhla Oasis). The combination between AMF and BY was better than used individually of them for controlling root rot /wilt disease severity. On the other hand, all treatments increased growth parameters viz. number of roots offshoot-1offshoot height (cm), number of leaves offshoot-1, leaflet number leaf-1, nick leaf thickness (cm) and leaf area (cm 2 in both The combination between AMF and BY significantly all growth parameters compared with used individually. all treatments increase leaf contents of nitrogen (N), phosphorus (P), potassium (K), sodium magnesium (Mg), calcium (Ca) and Chlorophyll a, b and carotenoid compared with control in both El-Dakhla). In biochemical studies, activity of defense-related enzymes, including peroxidase (PO), polyphenol oxidase (PPO), phenylalanine ammonia lyase (PAL) and catalase as well as total phenolic and flavonoids compounds were increased in offshoots treated with AMF and/or BY individually or in combination in both locations (El-Kharga and El-Dakhla). The combination between AMF and BY recorded the highest all oxidative enzymes, total phenolic and flavonoid compounds compared with AMF or BY alone. The present results showed that, the AMF and BY individually and/or in combination which tested as soil treatment as resistance inducer treatments increased activities of PO, PPO, PAL and CA enzymes and total phenolic and flavonoids compounds to different extents in leaves of date palm offshoots comparing to the untreated control. The combination between AMF and BY recorded the highest activities of all tested oxidative enzymes and total phenolic and flavonoid compounds.