Increased Silicon Acquisition in Bananas Colonized by Rhizophagus irregularis MUCL 41833 Reduces the Incidence of Pseudocercospora fijiensis

Abstract

This work aimed to test the hypothesis that the combination of arbuscular mycorrhizal fungi (AMF) and accumulation of silicon (Si) in banana plants via its uptake and transport by the fungus reduces the incidence of Black Leaf Steak Disease (BLSD) caused by Pseudocercospora fijiensis.Methods: A pot experiment was conducted to compare BLSD symptoms on leaves of banana plants colonized or not by the AMF Rhizophagus irregularis MUCL 41833 and exposed or not to Si added to the growth substrate.Results: A marked increase in plant growth parameters (i.e., pseudostem diameter and height, leaf surface area, shoot, root and total dry weight) as well as accumulation of Si, P, and Ca were noticed in the AMF-colonized banana plants in presence as well as in absence of Si added to the growth substrate. Similarly Si addition to the substrate increased plant growth parameters. Leave symptoms caused by the pathogen were observed in all the treatments but were reduced in presence of AMF as well as in presence of Si added to the growth substrate. The more drastic reduction was noticed in the AMF-colonized plants with Si added to the growth substrate. The Severity Index as well as Area Under Disease Progress Curve were considerably decreased both at 21 (∼48% and 48%, respectively) and 35 days (∼21% and ∼32%, respectively) after inoculation of the pathogen as compared with non-AMF-colonized plants in absence of Si added to the substrate.Conclusion: Our findings revealed that AMF-colonized banana plants grown in a subs-trate supplemented with Si were less impacted by P. fijiensis than non-colonized plants grown without Si added to the growth substrate. The combination of AMF-colonized banana plants (during the weaning phase or in vitro) with the application of Si to soil seems thus a thoughtful option to mitigate the impact of BLSD in bananas, although such strategy needs first to be evaluated under field conditions to appraise its real potential.

Contribution of Arbuscular Mycorrhizal Fungi, Phosphate–Solubilizing Bacteria, and Silicon to P Uptake by Plant

“…The benefits of Si nutrition, although significant, are limited due to its restricted uptake by plant (Anda et al, 2016). However, AMF such as Glomus etunicatum, G. versiform, G. coronatum, Rhizophagus clarus (=Glomus clarum), Rhizophagus irregularis (=Glomus intraradices), and Funneliformis mosseae (= Glomus mosseae) were observed to increase Si uptake in the roots and shoots of mycorrhizal plants (i.e., Saccharum spp., Glycine max L., Zea mays L., Cajanus cajan L., Cicer arietinum L., strawberry, and banana) compared to non-mycorrhizal plants (Yost and Fox, 1982;Kothari et al, 1990;Clark and Zeto, 1996;Clark and Zeto, 2000;Nogueira et al, 2002;Hammer et al, 2011;Garg and Singla, 2015;Anda et al, 2016;Garg and Bhandari, 2016a,b;Frew et al, 2017;Garg and Singh, 2018;Hajiboland et al, 2018;Gbongue et al, 2019;Moradtalab et al, 2019). AMF play a substantial role in Si uptake, translocation from the external solution to the intraradical mycelium, and transfer from the fungal cells to the root cells.…”

Unraveling Arbuscular Mycorrhiza-Induced Changes in Plant Primary and Secondary Metabolome

“…AMF provides resistance against many biotic and abiotic stresses [ 108 , 158 , 159 , 160 , 161 , 162 , 163 , 164 , 165 , 166 , 167 , 168 ]. Phenolic compounds are important secondary metabolites in disease suppression or defense mechanisms against other stress.…”

Effective Methods Based on Distinct Learning Principles for the Analysis of Hyperspectral Images to Detect Black Sigatoka Disease

“…For this study, 3–4-month-old plants were kept in a greenhouse at 28 °C in 70% relative humidity and 12 h of natural light and were watered every 48 h. In total, 16 plants were randomly selected, of which 10 were inoculated with P. fijiensis , and 6 were mock-inoculated with distilled autoclaved water. The inoculation was carried out using a conidial suspension prepared as suggested by Gbongue [ 22 ] and banana leaves were spray-inoculated with the concentrated conidia suspension using an aerograph atomizer (Gerensa, Guayaquil, Ecuador). The disease symptoms were monitored using the severity scale shown in Table 1 , as suggested by Fouré [ 23 ].…”