de Oliveira Jaqueline Aparecida, Custódio Fábio Alex, Pereira Olinto Liparini
Departamento de Microbiologia, Universidade Federal de Viçosa, Viçosa, 36570-900, Minas Gerais, Brazil.
Departamento de Fitopatologia, Universidade Federal de Viçosa, Viçosa, 36570-900, Minas Gerais, Brazil.
Braz J Microbiol. 2024 Dec;55(4):4077-4090. doi: 10.1007/s42770-024-01482-z. Epub 2024 Aug 27.
Macaw palm (Acrocomia aculeata Jacq.) is a palm, native to Brazilian territory that stands out due to the amount of oil produced with applications in the biodiesel industry, cosmetics, and food. Its commercial exploitation in Brazil, including phytosanitary management is based on concepts and practices of regenerative agriculture, which has the responsibility of sustainable cultivation by avoiding, for example, the use of chemical pesticides. Recently, root and stem rot disease were reported in macaw palm seedlings caused by Phytophthora palmivora. Managing this plant pathogen is complex, and the chemical control of this soil-borne oomycete is not viable, in addition to the negative impact on the environment. Many microorganisms are studied and used as biological control agents (BCAs) against pathogens, among them the community of endophytic fungi associated with plants. This is a sustainable biotechnological alternative for plant disease control. The community of cultivable endophytic fungi associated with healthy roots of macaw palm was explored using the extinction cultivation technique and a screening was carried out to select potential antagonists against oomycetes through the dual culture test. Specific gene regions from the best isolates were amplified for identification. A total of 250 isolates were obtained, and 46 were selected for in vitro tests against representatives of phytopathogenic oomycetes. After tests against Phytophthora heterospora, Phytophthora palmivora, Pythium aphanidermatum, and Pythium deliense, two isolates were selected as potential antagonists. The phylogenetic analysis of selected isolates showed that they belong to two different species: Talaromyces sayulitensis COAD 3605 and Epicoccum italicum COAD 3608. The percentage of inhibition of phytopathogenic oomycetes testedwas until 82% in the antagonism tests conducted. From the 46 isolates selected, only 2 were selected which showed great antagonistic activity towards all oomycetes tested. These fungi will be used in upcoming studies that aim to determine the effectiveness of endophytes in controlling diseases caused by oomycetes in the field.
金刚鹦鹉棕榈（Acrocomia aculeata Jacq.）是一种棕榈树，原产于巴西境内，因其产油量高而备受关注，其油可应用于生物柴油行业、化妆品和食品领域。在巴西，其商业开发，包括植物检疫管理，都基于再生农业的理念和实践，再生农业负责可持续种植，例如避免使用化学农药。最近，有报道称棕榈疫霉导致金刚鹦鹉棕榈幼苗出现根腐病和茎腐病。管理这种植物病原体很复杂，而且对这种土壤传播的卵菌进行化学防治不可行，此外还会对环境产生负面影响。许多微生物被研究并用作对抗病原体的生物防治剂（BCAs），其中包括与植物相关的内生真菌群落。这是一种用于植物病害防治的可持续生物技术替代方法。采用灭绝培养技术探索了与金刚鹦鹉棕榈健康根系相关的可培养内生真菌群落，并通过双培养试验进行筛选，以选择针对卵菌的潜在拮抗剂。对最佳分离株的特定基因区域进行扩增以进行鉴定。共获得250个分离株，其中46个被选用于针对植物病原卵菌代表的体外试验。在针对异孢疫霉、棕榈疫霉、瓜果腐霉和德氏腐霉进行试验后，选择了两个分离株作为潜在拮抗剂。对所选分离株的系统发育分析表明，它们属于两个不同的物种：萨尤利特青霉COAD 3605和意大利附球菌COAD 3608。在进行的拮抗试验中，受试植物病原卵菌的抑制率高达82%。从所选的46个分离株中，仅选出2个对所有受试卵菌表现出强大拮抗活性的分离株。这些真菌将用于后续研究，旨在确定内生菌在田间控制由卵菌引起的病害的有效性。
