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    Biocontrol of Leucoagaricus gongylophorus by Trichoderma asperelloides with implications to ant mini-colony survival
    (2025) Santos, Tássia Tuane Moreira dos; Mascarin, Gabriel Moura; Dunlap, Christopher A.; Chaibub, Amanda Abdallah; Pereira, Jaqueline Magalhães; Mendes, Letícia de Maria Oliveira; Ribeiro, Danielle Santos; Araújo, Leila Garcês de; Fernandes, Paulo Marçal
    Leaf-cutting ants (LCAs) of the genera Atta and Acromyrmex are major agricultural pests in the Americas, relying on their mutualism with the fungus Leucoagaricus gongylophorus for colony survival. Mycoparasites such as Trichoderma spp. offer promising biocontrol tools by antagonizing this essential symbiont. This study aimed to identify the most antagonistic isolate of Trichoderma asperelloides, elucidate its mechanisms of action against the fungal garden-symbiont L. gongylophorus, and further evaluate its indirect biocontrol activity on the health and survival of Atta sexdens mini-colonies. Isolates of T. asperelloides namely Tricho 4, Tricho 5, Tricho 7, and Tricho 11 exhibited strong antagonism, reducing L. gongylophorus colony growth by more than 94 % in dual culture assays. Additionally, antibiosis mechanism and volatile compound release by T. asperelloides induced over an 80 % reduction in L. gongylophorus growth. Moreover, exposure to these isolates significantly disrupted ant mini-colonies, leading to mortality rates of up to 60 % and a concurrent reduction in waste production, likely linked to the antagonism effects of T. asperelloides on the garden-symbiont fungus. Overall, these T. asperelloides isolates demonstrate potent antifungal activities against L. gongylophorus and may serve as a sustainable biological strategy for managing LCA colonies.
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    SNP-based genetic diversity of a network of germplasm banks to establish a core collection for the tropical fruit Hancornia speciosa
    (2025) Souza, Juliana Lopes; Alcântara, Bianca de Sousa; Chaves, Lázaro José; Rocha, Fernando Souza; Silva Junior, Josue Francisco da; Muniz, Ana Veruska Cruz da Silva; Silva Junior, Orzenil Bonfim da
    Hancornia speciosa is a tropical fruit and an important food resource native to Brazil. Its fruits, commercialized in natura or as a frozen pulp or ice cream, are an outstanding source of vitamins C, E, folates, and carotenoids. Despite its economic relevance, the species is still exploited in an extractive manner by harvesting natural populations, and no commercial varieties are available. A network of germplasm banks has been established from seeds and vegetative material collected in different regions throughout the Brazilian Atlantic Forest and Cerrado biomes. Nonetheless, resources are limited to maintain and evaluate all germplasm accessions for plant breeding. We used SNP markers generated by DArTSeq to assess the genetic diversity and population structure of 508 individual plant accessions conserved across three germplasm banks of H. speciosa and proposed a core collection for the species to be targeted for phenotypic characterization efforts. Significant genetic differentiation was found among the germplasm banks (Fst 0.221), with moderate genetic diversity and substantial inbreeding within each one, likely resulting from a Wahlund effect due to within-bank substructure as genetic entries were sampled from disjunct populations. A structure analysis assigned most of the germplasm accessions to two genetic groups, although some admixed individuals were observed. A core collection of 138 accessions (27.11%) was proposed, covering 98% of the currently conserved genetic diversity in the germplasm network. Although the proposed core collection provides a solid representation of the currently conserved genetic diversity for breeding, our results indicate that additional sampling of natural populations not yet surveyed should be pursued.
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    A framework for building enviromics matrices in mixed models
    (2025) Trevisan, Bruno Achcar; Junqueira, Vinícius Silva; Florêncio, Bruna de Mello; Coelho, Alexandre Siqueira Guedes; Marcatti, Gustavo Eduardo; Resende, Rafael Tassinari
    This study unravels a framework for constructing enviromics matrices within mixed models to integrategenetic and envirotypic data, enhancing phenotypic predictions in plant breeding. Enviromics leveragesdiverse data sources, such as climate and soil, to characterize genotype-by-environment (G×E) interac-tions. The approach uses block-diagonal structures in the design matrixZto incorporate random effectsfrom genetic and envirotypic covariates across trials. The covariance structure is modeled through theKronecker product of the genetic relationship matrixAand an identity matrixIrepresenting envirotypiceffects, effectively capturing both genetic and environmental variability. This dual representation facili-tates more accurate predictions of crop performance (y) across environments, enabling improved selectionstrategies in breeding programs. The framework is compatible with widely used mixed model software,including rrBLUP and BGLR, and is adaptable to account for more complex interactions. By integrat-ing genetic relationships (A) and environmental influences (Z), this approach provides a robust tool foradvancing G×E studies and accelerating the development of superior crop varieties.
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    Harnessing fuzzy logic for adaptive and stable selection of upland rice lines
    (2025) Maciel, Douglas de Oliveira; Guimarães, Paulo Henrique Ramos; Melo, Patrícia Guimarães Santos
    Abstract: Fuzzy logic enables automated decision-making and classifies genotype suitability across environments. This study assessed the adaptability and stability of upland rice genotypes using fuzzy logic. To do so, eight lines from the Federal University of Goiás, 10 from the Federal University of Lavras, and two commercial cultivars were evaluated for grain yield, plant height, and flowering days in 13 environments in Goiás. The trials used a randomized complete block design with three replications. Adaptability and stability were analyzed using fuzzy controllers, which classified genotypes into four groups: general adaptability, poorly adapted, favorable, and unfavorable environments. The CSD 08004 line exhibited broad adaptability and stability for yield and plant height and was close to general adaptability for flowering days, making it suitable for cultivation in Goiás.
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    Nota técnica elaborada por grupo de trabalho de regulamentação científica da cannabis: propostas para a consolidação da pesquisa com cannabis no Brasil
    (2025) Emygdio, Beatriz Marti; Silva, Letícia da Costa e; Mazzola, Priscila Gava; Martim, Silvia Aparecida; Moura, Túlio Flávio Accioly de Lima e; Melo, Patrícia Guimarães Santos; Stein, Vanessa Cristina; Almeida, Joaquim Maurício Duarte; Fegadolli, Claudia; Mandelli, Dalmo