Enhancement of alkalinity tolerance in two cucumber genotypes inoculated with an arbuscular mycorrhizal biofertilizer containing Glomus intraradices

Abstract

The aim of the present study was to determine whether arbuscular mycorrhizal (AM) inoculation with a biofertilizer containing clays as granular carriers, leek root pieces and Glomus intraradices spores could improve alkalinity tolerance of two cucumber genotypes, and to study the changes induced by AM at agronomical and physiological level. A greenhouse experiment was carried out to determine yield, growth, fruit quality, net photosynthesis (ACO2), electrolyte leakage, and mineral composition of two cucumber (Cucumis sativus L.) genotypes (hybrid “Ekron” or open-pollinated variety “Marketmore”) with inoculated and noninoculated arbuscular mycorrhizal biofertilizer. Plants were supplied with nutrient solutions at two pH values (6.0 or 8.1). The high pH nutrient solution had the same basic composition with an additional 10 mM NaHCO3 and 0.5 gl−1 CaCO3. The percentage root colonization was higher in “Marketmore” (21.8%) than “Ekron” (12.7%). Total and marketable yield and total biomass were significantly higher by 189%, 213%, and 77%, respectively, with Ekron in comparison to those recorded with Marketmore. The highest crop performance with Ekron in comparison to Marketmore was due to the improved nutritional status (higher N, P, K, Ca, Mg, Fe, Mn, and B), higher leaf area, and net photosynthesis. Increasing the concentration of NaHCO3 from 0 to 10 mM in the nutrient solution significantly decreased yield, plant growth, ACO2, N, P, Fe, Cu, Zn, Mn, and B concentration in leaf tissue, whereas the electrolyte leakage increased. The inoculated plants under alkaline conditions had higher total, marketable yield, and total biomass than noninoculated plant. Mycorrhizal cucumber plants grown under alkaline conditions had a higher macronutrient concentration in leaf tissue compared to noninoculated plants. The highest yield and biomass production in inoculated plants seems to be related to the capacity of maintaining higher net ACO2 and to a better nutritional status (high P, K, Mg, Fe, Zn, and Mn and low Na accumulation) in response to bicarbonate stress with respect to −AM plants

Co‐inoculation of Glomus intraradices and Trichoderma atroviride acts as a biostimulant to promote growth, yield and nutrient uptake of vegetable crops

“…The increase in root growth and the development of an external mycelium enhanced the nutrient uptake of the tested crops. Our results are in line with those of Rouphael et al and Cardarelli et al , who observed an improvement in nutrient uptake when plants were inoculated with G. intraradices BEG72. The better plant nutritional status due to greater absorption of nutrients in the greenhouse (e.g.…”

“…The association of AM fungi with plant roots alters plant–soil interactions and enhances plant growth under stressful edaphic conditions . AM fungi have been shown to enhance plant nutrient acquisition (P, N, K), overcome the detrimental effects of salinity and alkalinity, improve drought tolerance through greater effective root area and penetration of the substrate, and activate and excrete various enzymes of infected AM fungi roots and/or hyphae…”

“…7 The association of AM fungi with plant roots alters plant-soil interactions and enhances plant growth under stressful edaphic conditions. 8 AM fungi have been shown to enhance plant nutrient acquisition (P, N, K), 9 overcome the detrimental effects of salinity 10 and alkalinity, 11 improve drought tolerance 12 through greater effective root area and penetration of the substrate, and activate and excrete various enzymes of infected AM fungi roots and/or hyphae. 8 Trichoderma is a genus of saprotrophic fungi that have also been reported to promote plant growth, in addition to their biocontrol activities, acting by either the production of antimicrobial compounds or the parasitism of fungal plant pathogens.…”

Effects of Preconditioning Through Mycorrhizal Inoculation on the Control of Melon Root Rot and Vine Decline Caused by Monosporascus cannonballus

“…CaCO 3 (4 g/l) was added to peat to obtain a pH of 7.0. Prior to sowing, half of the pots were inoculated with R. irregularis (Aegis Irriga, Italpollina SpA., Verona, Italy) carrying 100 spores/ml by mixing 1 m 3 of the substrate with 15 l of inoculum mixture (Rouphael et al 2010). Three pregerminated seeds were planted in each pot and were thinned to one plant per pot after establishment.…”

Current Knowledge in Physiological and Genetic Mechanisms Underpinning Tolerances to Alkaline and Saline Subsoil Constraints of Broad Acre Cropping in Dryland Regions

“…Plants show minor to severe stunting of growth depending on HCO 3 − concentration in the soil solution. Growth of many commercial crops such as bean (Valdez-Aguilar & Reed, 2008;, cucumber (Rouphael et al, 2010), wheat (Yang et al, 2008c), sorghum, maize barley (Alhendawi et al, 1997;Yang et al, 2009), soybean (Rogovska et al ,2009), sunflower (Alcántara et al, 1988Shi & Sheng, 2005), tomato (Bailey & Hammer, 1986;Bialczyk & Lechowsk, 1995;Bialczyk et al, 2004;Navarro et al, 2000), pea (Zribi & Gharsalli, 2002), and rice (Hajiboland et al, 2005;Yang et al, 1994) are reported to be www.intechopen.com considerably affected by HCO 3 − . Toxic concentrations of bicarbonate can diminish leaf area, leaf length and leaf width, consequently shoot biomass is decreased.…”