Antagonistic Effects of Trichoderma harzianum Isolates against Ceratocystis radicicola: pioneering a Biocontrol Strategy against Black Scorch Disease in Date Palm Trees

Abstract

Date palm is an important subsistence crop in arid regions due to its ability to grow under adverse environmental conditions such as high temperature, salinity and drought. Nevertheless, ideal conditions for its growth and production are also favourable to fungal diseases such as black scorch disease caused by Ceratocystis radicicola. The aim of this study was to develop a method of biological control through the isolation, identification and examination of the effectiveness of bioagents in controlling black scorch disease. Twenty-five isolates of Trichoderma spp. were isolated from the rhizosphere of healthy date palm trees and morphological, microscopic and molecular approaches confirmed the identity of 11 isolates as Trichoderma harzianum species complex (THSC). In vivo study, application of both spore suspension and culture filtrates of T. harzianum decreased the size of necroses caused by C. radicicola. Additionally, scanning electron microscopy (SEM) showed lysis of the hyphal pathogen and phialoconidia along with scattered aleurioconidia. Results from the volatile metabolic assay and SEM suggested potential roles of cell wall degradation enzymes and volatile substances produced by T. harzianum as two collective mechanisms leading to degrade the cell wall of the pathogen and inhibit fungal growth. Altogether, results from our study demonstrated the efficacy and utility of using bioagents to control black scorch disease which could improve date palm yield.

Streptomyces globosus UAE1, a Potential Effective Biocontrol Agent for Black Scorch Disease in Date Palm Plantations

“…This suggests that the Streptomyces strain isolated in this study can serve as a potential antifungal product against T. punctulata . Whilst a number of recent reports have focused on biological controls using species of Trichoderma or Chaetomium against T. punctulata or T. paradoxa growth ( Soytong et al, 2005 ; Chakrabarty et al, 2013 ; Al-Naemi et al, 2016 ), the current study demonstrates, for the first time, the feasibility of using a streptomycete actinomycete isolate as a BCA against black scorch disease caused by T. punctulata .…”

“…Biological control, also known as biocontrol, can limit the increases in pathogen populations, and often suppress the plant tissue destroying activities of pathogens by other organism(s) (AbuQamar et al, 2017). In vitro and in vivo experiments using species of Trichoderma , Chaetomium or their antagonistic products were applied to control black scorch pathogens (Soytong et al, 2005; Sánchez et al, 2007; Ammar, 2011; Al-Naemi et al, 2016). …”

Biological Management of Basal Rot of Onion by Trichoderma harzianum and Withania somnifera

“…are very beneficial fungi and have the ability to control many pathogens (Fontenelle et al, 2011;Tchameni et al, 2011). Application of culture filtrates and spore suspension of T. harzianum reduced the size of necrotic spots of black scorch disease of date palm caused by Ceratocystis radicicola (Al-Naemi et al, 2016). T. harzianum is also known to reduce severity of leaf blotch of wheat caused by Zymoseptoria tritici (Stocco et al, 2016).…”

“…Trichoderma is among the most commonly used biocontrol agents and is an effective antagonist against plant pathogenic fungi ( Kumar and Mukerji, 1996;Stocco et al, 2016). Recent studies have shown that Trichoderma spp., especially T. harzianum, can control diseases caused by Rhizoctonia solani, Macrophomina phaseolina and Ceratocystis radicicola (Al-Naemi et al, 2016;Javaid et al, 2017b;Youssef et al, 2016).…”

“…However, synthetic fungicides have adverse effects on the environment and also affect the beneficial microorganisms present in the field soil (Muñoz-Leoz et al, 2013;Mimbs et al, 2016). Management of plant pathogens by biological means is considered an alternative environment friendly strategy for sustainable agriculture (Al-Naemi et al, 2016;Youssef et al, 2016). Trichoderma is among the most commonly used biocontrol agents and is an effective antagonist against plant pathogenic fungi ( Kumar and Mukerji, 1996;Stocco et al, 2016).…”