Escudero-Leyva Efraín, Granados-Montero María Del Milagro, Orozco-Ortiz Cristofer, Araya-Valverde Emmanuel, Alvarado-Picado Eduardo, Chaves-Fallas José Miguel, Aldrich-Wolfe Laura, Chaverri Priscila
Centro de Investigaciones en Productos Naturales (CIPRONA) and Escuela de Biología, Universidad de Costa Rica, San Pedro, San José 11801, Costa Rica.
Centro Nacional de Innovaciones Biotecnológicas (CENIBiot), CeNAT-CONARE, Pavas, San José 10109, Costa Rica.
J Appl Microbiol. 2023 May 2;134(5). doi: 10.1093/jambio/lxad090.
The American leaf spot, caused by Mycena citricolor, is an important disease of coffee (Coffea arabica), mostly in Central America. Currently, there are limited pathogen control alternatives that are environment friendly and economically accessible. The use of fungi isolated from the plant endomycobiota in their native habitats is on the rise because studies show their great potential for biological control. To begin to generate a green alternative to control M. citricolor, the objectives of the present study were to (i) collect, identify, screen (in vitro and in planta), and select endophytic fungi from wild Rubiaceae collected in old-growth forests of Costa Rica; (ii) confirm endophytic colonization in coffee plantlets; (iii) evaluate the effects of the endophytes on plantlet development; and (iv) corroborate the antagonistic ability in planta.
Through in vitro and in planta antagonism assays, we found that out of the selected isolates (i.e. Daldinia eschscholzii GU11N, Nectria pseudotrichia GUHN1, Purpureocillium aff. lilacinum CT24, Sarocladium aff. kiliense CT25, Trichoderma rifaii CT5, T. aff. crassum G1C, T. aff. atroviride G7T, T. aff. strigosellum GU12, and Xylaria multiplex GU14T), Trichoderma spp. produced the highest growth inhibition percentages in vitro. Trichoderma isolates CT5 and G1C were then tested in planta using Coffea arabica cv. caturra plantlets. Endophytic colonization was verified, followed by in planta growth promotion and antagonism assays.
Results show that Trichoderma isolates CT5 and G1C have potential for plant growth promotion and antagonism against Mycena citricolor, reducing incidence and severity, and preventing plant mortality.
由柠檬蜡蘑（Mycena citricolor）引起的美洲叶斑病是咖啡（Coffea arabica）的一种重要病害，主要发生在中美洲。目前，环境友好且经济可行的病原体控制方法有限。由于研究表明从植物内生真菌群落中分离的真菌在其原生栖息地具有巨大的生物防治潜力，因此对其的利用正在增加。为了开始开发一种绿色替代方法来控制柠檬蜡蘑，本研究的目标是：（i）从在哥斯达黎加原始森林中采集的野生茜草科植物中收集、鉴定、筛选（体外和体内）并选择内生真菌；（ii）确认咖啡幼苗中的内生定殖；（iii）评估内生菌对幼苗发育的影响；（iv）证实体内的拮抗能力。
通过体外和体内拮抗试验，我们发现在所选择的分离株（即埃氏炭团菌（Daldinia eschscholzii）GU11N、假毛壳菌（Nectria pseudotrichia）GUHN1、类淡紫拟青霉（Purpureocillium aff. lilacinum）CT24、类基利安帚梗柱孢（Sarocladium aff. kiliense）CT25、里氏木霉（Trichoderma rifaii）CT5、类厚垣木霉（T. aff. crassum）G1C、类绿色木霉（T. aff. atroviride）G7T、类细梗木霉（T. aff. strigosellum）GU12和多隔炭角菌（Xylaria multiplex）GU14T）中，木霉属在体外产生的生长抑制率最高。然后使用卡杜拉咖啡（Coffea arabica cv. caturra）幼苗在体内对木霉分离株CT5和G1C进行测试。验证了内生定殖，随后进行了体内生长促进和拮抗试验。
结果表明，木霉分离株CT5和G1C具有促进植物生长和拮抗柠檬蜡蘑的潜力，可降低发病率和严重程度，并防止植物死亡。
