Selection of Trichoderma isolates for biological control of Sclerotinia minor and S. sclerotiorum in lettuce

Abstract

Lettuce drop is one of the most important and difficult-to-control diseases affecting lettuce in Brazil and worldwide. This study was carried out to select Trichoderma isolates antagonistic to Sclerotinia minor and S. sclerotiorum, aiming to develop biological control for this pathosystem in Brazil. Thirty-one Trichoderma isolates were obtained with the use of baits and were tested under laboratory conditions for their ability to control S. minor and S. sclerotiorum in seedlings of lettuce cultivar Tainá cultured in Petri dishes containing water-agar medium. Subsequently, four isolates effective for control and showing high sporulation under laboratory conditions were evaluated in greenhouse in two experiments carried out with both pathogens in lettuce seedlings of the same cultivar. Twenty-two isolates showed ability to control S. minor and S. sclerotiorum in the in vitro experiments. The isolates tested under greenhouse conditions, identified as T. asperellum (IBLF 897, IBLF 904 and IBLF 914) and T. asperelloides (IBLF 908), reduced lettuce drop of seedlings caused by both pathogens but were more effective against S. minor. Biological control is a promising technology for the management of lettuce drop, especially because S. minor is the predominant species in infested lettuce fields in Brazil.

Introductory Chapter: Identification and Isolation of Trichoderma spp. - Their Significance in Agriculture, Human Health, Industrial and Environmental Application

“…Various articles reported on the role of Trichoderma spp. as antagonist to plant pathogens such as T. harzianum, T. asperellum, and T. virens against Phytophthora capsici in red pepper [16]; Trichoderma isolates against Sclerotium rolfsii, Colletotrichum gloeosporioides, C. capsici [37], S. minor and S. sclerotiorum in the in vitro experiments [38]; T. atroviride SY3A and T. harzianum SYN were effective biological control agents of R. solani damping-off of cucumber [39]; Trichoderma isolates were antagonist to soil-borne phytopathogenic fungi (Fusarium graminearum, Rhizoctonia solani, Macrophomina phaseoli, and Phytophtora cactorum) [9]; Trichoderma species was antagonist to anthracnose of strawberry [5]; Trichoderma isolates inhibit and control the growth of Fusarium oxysporum with Trichoderma harzianum being the most effective [40]; T. viride, T. polysporum, and T. harzianum inhibit more than 60% growth of C. paradoxa [19]; T. hamatum LU593 and T. virens LU556 delayed aphids manifestation on cabbage [41]; Trichoderma isolates against Sclerotium rolfsii [6]; Trichoderma isolates against Fusarium sambucinum [42]; and Trichoderma spp. and Bacillus spp.…”

Functional Hyperspectral Imaging by High-Related Vegetation Indices to Track the Wide-Spectrum Trichoderma Biocontrol Activity Against Soil-Borne Diseases of Baby-Leaf Vegetables

“…On the other hand, the biological control of Sclerotinia species, in particular S. sclerotiorum , has received increasing attention on adult lettuce inasmuch as chemical control of this pathogen is usually difficult, because the ascospores can infect any part of the head and sclerotia resist in the soil and can occur after prolonged wet periods (Patterson and Grogan, 1985 ; Elias et al, 2016 ; Subbarao et al, 2017 ). Therefore, the antagonists play a crucial role in the lettuce drop management because of their ability to parasitize the sclerotia in deep soil layers (Subbarao, 1998 ).…”

“…Furthermore, against the compatible interaction between Sclerotinia spp . and adult lettuces, Trichoderma biocontrol agents have been reported to effectively reduce the seedlings drop (Elias et al, 2016 ), promote plant growth under infection (da Silva et al, 2019 ) and delay the symptoms appearance by emitting volatiles (da Silva et al, 2021 ). Accordingly, our results on baby lettuces demonstrated that Trichoderma strains Ta100, Ta104C, Ta117, Tl35, Ta56, TaIC12, Tat3C1, ThCB, and Th23, belonging to different species, can contain Sclerotinia drop disease, reaching a significant reduction of DSI (around 30%) compared to untreated control (DSI 100%).…”

Antagonism of saprobe fungi from semiarid areas of the Northeast of Brazil against Sclerotinia sclerotiorum and biocontrol of soybean white mold

“…include bacteria, mainly in the genus Bacillus (Zeng,Wang, Kirk, & Hao, 2012;Kamal, Lindbeck, Savocchia, & Ash, 2015;Vinodkumar, Nakkeeran, Renukadevi, & Malathi, 2017). Nevertheless, much research has been focused on species of antagonistic or mycoparasitic fungi, including Clonostachys rosea (Preuss) Mussat (Hypocreales: Bionectriaceae) (Rabeendran, Jones, Moot, & Stewart, 2006), Dictyosporium elegans (Corda) (Pleosporales: Dictyosporiaceae) (McCredie & Sivasithamparam, 1985), and several species of Gliocladium and Trichoderma (Geraldine et al, 2013;Zhang et al, 2016;Elias, Domingues, Moura, Harakava, & Patricio, 2016;Sumida et al, 2018), Paraphaeosphaeria minitans (Campb.) Verkley, Göker, Stielow (Pleosporales: Didymosphaeriaceae) (formerly Coniothyrium minitans) (Whipps, Sreenivasaprasad, Muthumeenakshi, Rogers, & Challen, 2008;Zeng et al, 2012;Nicot et al, 2019), and Paecilomyces lilacinus (Thom) Samson (Eurotiales: Aspergillaceae) (Yang, Abdelnabby, & Xiao, 2015).…”