Fungal Endophytes of Tahiti Lime (Citrus citrus × latifolia) and Their Potential for Control of Colletotrichum acutatum J. H. Simmonds Causing Anthracnose

Abstract

Colletotrichum acutatum is one of the causal agents of anthracnose in several crops, and of post-flowering fruit drop (PFD) in citrus and key lime anthracnose (KLA). The pathogen normally attacks flowers, causing lesions only in open flowers. Under very favorable conditions, however, it can also affect flower buds and small fruits, causing complete rotting of the fruit and a premature fall, resulting in major economic crop losses. We isolated endophytic fungi from Tahiti lime to evaluate its diversity, verify its antagonistic capacity against the phytopathogen Colletotrichum acutatum C-100 in dual tests, and evaluate the ability of various endophytic agents to control flowers with induced anthracnose. 138 fungal isolates were obtained from 486 fragments of branches, leaves, and fruit; from which 15 species were identified morphologically. A higher isolation frequency was found in branches and leaves, with a normal level of diversity compared to other citrus species. Of the 15 morphospecies, 5 were trialed against C. acutatum in antagonism tests, resulting in a finding of positive inhibition. 2 endophytic fungi from the antagonism tests demonstrated high inhibition of the phytopathogen, and were thus used in in vivo tests with Tahiti lime flowers, applied in a spore solution. Spore solutions of two molecularly identified species, Xylaria adscendens, and Trichoderma atroviride, reduced the lesions caused by the phytopathogen in these in vivo tests. The finding that these endophytes react antagonistically against C. acutatum may make them good candidates for further biological control research in an agroindustry that requires environmental sustainability.

Antofine Triggers the Resistance Against Penicillium italicum in Ponkan Fruit by Driving AsA-GSH Cycle and ROS-Scavenging System

“…Postharvest production of citrus fruits has been plagued by the fungal infection caused by various pathogens, such as Penicillium spp. (blue and green mold), Geotrichum citri-aurantii (sour rot), Colletotrichum acutatum (anthracnose), and Diaporthe citri ( Phomopsis stem-end rot) ( Kanashiro et al, 2020 ; Duan et al, 2021 ; Elsherbiny et al, 2021 ; Muñoz-Guerrero et al, 2021 ). As promising alternatives to conventional synthetic fungicides, PAAs have received increasing attention due to their great potential for controlling postharvest fungal decay and maintaining the nutritional quality of citrus fruits.…”

“Delaying Rot Emergence in Persian Lime (Citrus×latifolia) Through Antifungal Hybrid Films Containing Litsea glaucescens Essential Oil”

“…[4] Before exportation, Persian limes must be subjected to fruit quality screening which is unfortunately affected by fungal attack. [4][5] Fungal infections represent a significant challenge because of the high relative humidity and precipitation rate in which Persian lime trees grow. As is known, these factors facilitate the proliferation of opportunistic species under wild conditions.…”

“…[4] Remarkably, C. gloeosporioides and Penicillium digitatum cause severe economic losses during the postharvest period which are translated into substantial affectation of the production chain (Figure 1). [5][6] To reduce the incidence of both phytopathogens, several approaches have been performed. Synthetic fungicides such as prochloraz are regularly sprayed on fruit to delay fungal proliferation and represent the first choice to reduce rot occurrence during the postharvest period.…”

“…[5] However, this technique faces big challenges since the mechanisms and strategies to assure microbial viability under contrasting wild conditions, need to be considered and improved. [5] Based on the latter points, recent efforts have focused on applying fungistatic films made with chitosan and essential oils as biodegradable/edible coatings for controlling pathogens linked to fruit decay during the postharvest period. [10][11][12][13][14] Previous studies sustain that hybrid films containing chitosan impregnated with essential oils, efficiently regulate the standard growth of Fusarium verticillioides, F. solani, and Clonostachys rosea in avocado fruit.…”

Endophytic Fungi Associated with Coffee Leaves in China Exhibited In Vitro Antagonism against Fungal and Bacterial Pathogens

“…These are: (i) plant growth promotion, including nutrient uptake, photostimulation, and phosphate solubilization; (ii) plant health and protection (antimicrobial activities and pathogen displacement); (iii) pollution control and phytoremediation; and (iv) medical and industrial applications (anticancer and antiviral). Since endophytes can produce large amounts of biologically active substances, the use of endophytes to control plant diseases and to increase crop yields has become the focus of the agricultural industry [ 17 , 35 , 36 , 37 ].…”