Matheus Alves Silva’s research while affiliated with Federal University of Espírito Santo and other places

Psidium guajava L., a fruit crop belonging to the Myrtaceae family, is highly valued for its nutritional and medicinal properties. The family exhibits a diverse chemical profile of essential oils and serves as a valuable resource due to its ecological interactions, adaptability, and dispersal capacity. The Myrtaceae family has been extensively studied for its terpenoids. Genetic studies have focused on foliar terpene yield in species from the Eucalypteae and Melaleucaceae tribes. To understand the evolutionary trends in guava breeding, this study predicted terpene synthase genes (TPS) from different cultivars. Through this analysis, 43 full-length TPS genes were identified, and approximately 77% of them exhibited relative expression in at least one of the five investigated plant tissues (root, leaf, bud, flower, and fruit) of two guava cultivars. We identified intra-species variation in the terpene profile and single nucleotide polymorphisms (SNPs) in twelve TPS genes, resulting in the clustering of 62 genotypes according to their essential oil chemotypes. The high concentration of sesquiterpenes is supported by the higher number of TPS-a genes and their expression. The expansion for TPS sub-families in P. guajava occurred after the expansion of other rosids species. Providing insight into the origin of structural diversification and expansion in each clade of the TPS gene family within Myrtaceae. This study can provide insights into the diversity of genes for specialized metabolites such as terpenes, and their regulation, which can lead to a diverse chemotype of essential oil in different tissues and genotypes. This suggests a mode of enzymatic evolution that could lead to high sesquiterpene production, act as a chemical defense and contribute to the adaptive capacity of this species to different habitats.

The search for bioherbicides has been encouraged, and plants used in food or with bioactivity have been studied. Therefore, this article aimed to investigate the bioherbicidal potential of essential oils from Psidium cauliflorum and P. acidum through a plant toxicity bioassay using Lactuca sativa and Sorghum bicolor. The seeds were treated with essential oils of both species, along with control groups treated with distilled water, dichloromethane, and glyphosate. Germination percentage (GP), germination speed index (GSI), root growth (RG), shoot length (SL), mitotic index (MI), chromosomal alterations (CA), and nuclear alterations (NA) were evaluated. The major compound of the essential oil of P. cauliflorum was α-pinene, and of P. acidum were trans-caryophyllene, β-elemene, germacrene A, and α-copaene. The essential oils from both species exhibited phytotoxic effects. P. acidum oil inhibited sorghum RG and lettuce SL, while P. cauliflorum oil reduced GP, GSI, RG, and SL in both plants, indicating higher phytotoxicity than P. acidum and non-selective behavior. Cytotoxic investigations showed that both oils inhibited the MI. CA analysis revealed that P. cauliflorum oil exhibited aneugenic and clastogenic action mechanisms. The results demonstrate the bioherbicidal potential of P. cauliflorum essential oil, in addition to being non-selective and displaying a similar inhibition rate to glyphosate. Key words bioherbicides; cytogenetics; plant bioassay; secondary metabolites

The present investigation aimed to develop inclusion complexes (ICs) from Psidium gaudichaudianum (GAU) essential oil (EO) and its major compound β-caryophyllene (β-CAR), and to evaluate their herbicidal (against Lolium multiflorum and Bidens pilosa) and cytogenotoxic (on Lactuca sativa) activities. The ICs were obtained using 2-hydroxypropyl-β-cyclodextrin (HPβCD) and they were prepared to avoid or reduce the volatility and degradation of GAU EO and β-CAR. The ICs obtained showed a complexation efficiency of 91.5 and 83.9% for GAU EO and β-CAR, respectively. The IC of GAU EO at a concentration of 3000 µg mL⁻¹ displayed a significant effect against weed species B. pilosa and L. multiflorum. However, the β-CAR IC at a concentration of 3000 µg mL⁻¹ was effective only on L. multiflorum. In addition, the cytogenotoxic activity evaluation revealed that there was a reduction in the mitotic index and an increase in chromosomal abnormalities. The produced ICs were able to protect the EO and β-CAR from volatility and degradation, with a high thermal stability, and they also enabled the solubilization of the EO and β-CAR in water without the addition of an organic solvent. Therefore, it is possible to indicate the obtained products as potential candidates for commercial exploration since the ICs allow the complexed EO to exhibit a more stable chemical constitution than pure EO under storage conditions.

Diploid and polyploid species derived from the euploid series x = 11 occur in the genus Psidium, as well as intraspecific cytotypes. Euploidy in the genus can alter the gene copy number, resulting in several “omics” variations. We revisited the euploidy, reported genomic (nuclear 2C value, GC%, and copy number of secondary metabolism genes) and epigenomic (5-mC%) differences in Psidium, and related them to essential oil yield and composition. Mean 2C values ranged from 0.90 pg (P. guajava) to 7.40 pg (P. gaudichaudianum). 2C value is intraspecifically varied in P. cattleyanum and P. gaudichaudianum, evidencing cytotypes that can be formed from euploid (non-reduced) and/or aneuploid reproductive cells. GC% ranged from 34.33% (P. guineense) to 48.95% (P. myrtoides), and intraspecific variations occurred even for species without 2C value intraspecific variation. Essential oil yield increased in relation to 2C value and to GC%. We showed that P. guajava (diploid) possesses two and P. guineense (tetraploid) four copies of the one specific TPS gene, as well as eight and sixteen copies respectively of the conserved regions that occur in eight TPS genes. We provide a wide “omics'' characterization of Psidium and show the outcome of the genome and epigenome variation in secondary metabolism.

The genetic diversity of Coffea canephora Pierre ex A. Froehner present in old seminal crops must be characterized because it represents a source of genetic variability for breeding programs. In this study, the genetic diversity of 388 half‐sib families of C. canephora, collected from Espírito Santo, Brazil, were assessed for their phenotypic traits. The data were obtained in a trial planted in April 2018 with five commercial clones as controls. Vegetative development was evaluated based on plant height, stem diameter, and average height and diameter growth rates. Abiotic (drought) and biotic (rust, leaf miner, and mealybug) stresses were evaluated by a rating scale. The phenotypic variability of the population was detected for all traits, and divergent clusters of families were identified. Negative correlations indicated that adverse conditions hampered the early development of the coffee plants. Groups of families should be investigated for breeding programs according to adequate development even under stressful conditions. These results show the importance of preserving the germplasm of old crops in the south of Espírito Santo as a source of genetic resources for coffee breeding programs. This valuable resource should be maintained and conserved as a strategy to guarantee the sustainability of coffee production.

The common bean (Phaseolus vulgaris L., Fabaceae) is the most important legume of the genus Phaseolus, and the most cultivated in family farming. This study aimed to characterize landrace beans by SSR markers and morphoagronomic variables, comparing them to commercial cultivars. A total of 185 accessions (158 landrace and 27 commercial) were evaluated using SSR, and later 50 accessions (37 landrace and 13 commercial cultivars) were evaluated by 12 morphoagronomic variables. The estimators of genetic diversity, expected heterozygosity, allelic number, private, and rare alleles showed greater magnitude in landrace accessions, indicating the potential of these accessions as a reservoir of rare and private alleles compared to commercial stocks. Ten groups were observed in the cluster analysis, of which one group had 89% of accessions (138 landrace and all commercial ones). For morphoagronomic characterization, three field experiments were carried out in randomized blocks with three replications, one in Alegre, ES and two in Mimoso do Sul, ES. The accessions Verde-111, Branco-110, Pérola-102, Preto-13-69, Feijão Rainha-18, and Branco-05 showed high productivity levels (above 3000 kg ha−1) and six groups were formed. Most landrace accessions and commercial cultivars were allocated into the same group, suggesting that landrace beans have characteristics of interest compared to the commercial ones. The variability detected in landrace beans is of strategic importance, given the selection carried out by farmers for materials adapted to their local conditions. Thus, the development of policies to support the conservation of bean trees on rural properties is indicated as a measure to preserve diversity.

O Complexo Juiz de Fora (CJF) compreende ortognaisses e ortogranulitos paleoproterozoicos com uma ampla variação composicional, interpretados como produto de um arco magmático edificado entre o Sideriano e o Orosiriano e retrabalhado durante o Neoproterozoico com desenvolvimento das orogenias Brasilianas/Pan-Africanas, aflorante como inliers em meio ao Sistema Orogênico Araçuaí-Ribeira (SOAR). Este trabalho apresenta dados inéditos de geocronologia U-Pb em zircão (LA-MC-ICP-MS) combinados com isótopos de Sm-Nd e Sr, litogeoquímica, petrografia e observações de campo do CJF na região de Pedra Dourada (MG). Os dados permitem o reconhecimento de dois litotipos: ortogranulitos félsicos e ortogranulitos máficos. O ortogranulito félsico possui composição diorítica a granodiorítica, conteúdos intermediários de SiO2, moderado a alto Ba, Sr, Mg#, moderada razão (La/Yb)N e baixa razão Na2O/K2O, estas características, além de compatíveis com granitoides de arco magmático, mostram afinidade com a série sanukitoide. Análises em núcleos de zircão com forte zoneamento oscilatório típico de zircões ígneos sugerem cristalização magmática em 2175 Ma, enquanto análises de Sm-Nd e Sr em rocha total informam εNd inicial entre -4,0 e +0,5, TDMs entre 2,57 e 2,12 Ga e razões iniciais de 87Sr/86Sr entre 0,6937 e 0,7137, informando assinaturas moderadamente juvenis a ligeiramente evoluídas e sugerindo uma origem em magmas oriundos de um manto híbrido extensivamente enriquecido pela assimilação de material crustal (fluídos, sedimentos, melt) por um longo período de subducção e/ou por eventos de subducção anteriores. O ortogranulito máfico, litotipo subordinado, apresenta composição gabroica, alto enriquecimento em elementos terras raras e forte anomalia negativa de Eu, sendo classificado como um OIB (Ocean Island Basalt). Análises em núcleos de zircão com zoneamento oscilatório, típico de zircões ígneos, sugerem cristalização magmática em 2102 Ma. Os dados isotópicos (com εNd inicial igual a -5,5, TDM de 2,61 Ga e razão inicial 87Sr/86Sr igual a 0,7020) sugerem uma significativa contribuição de fontes crustais e a origem desta rocha em um ambiente de arco por meio de um slab-window. Tanto o ortogranulito félsico como o ortogranulito máfico exibem paragêneses de pico metamórfico com Opx + Cpx + Pl estáveis, parcialmente substituídas por Hbl e Bt retrógradas. O alto grau metamórfico também é sugerido por bordas sobrecrescidas ao redor de núcleos ígneos parcialmente consumidos de zircão, sendo obtida para estas bordas idades entre 581 e 605 Ma, compatíveis com a colisão do que veio à constituir o Cráton São Francisco com o arco interno cordilheirano (o Arco Serra da Bolívia) na amalgamação do Supercontinente Gondwana. Por fim, em síntese, os dados obtidos corroboram o atual modelo de evolução do CJF, interpretado como inliers remanescentes de um arco magmático paleoproterozoico retrabalhado e metamorfisado em fácies granulito durante o Ediacarano no desenvolvimento do SOAR.

O Paleoproterozoico é reconhecido como um período de intensa atividade tectônica global com criação de crosta juvenil e retrabalhamento crustal, em processos orogênicos relacionados à formação do Supercontinente Colúmbia. No sudoeste do estado do Espírito Santo, estes processos são registrados em diferentes inliers paleoproterozoicos que foram retrabalhados durante o Neoproterozoico dentro do Sistema Orogênico Araçuaí-Ribeira, sendo exemplos destes inliers os complexos Juiz de Fora (CJF), Caparaó (CC) e Serra do Valentim (CSV). O entendimento da evolução geodinâmica destes complexos e o traçado de correlações entre os mesmos é essencial para o entendimento da evolução policíclica regional e constitui o problema abordado neste trabalho. São apresentados resultados parciais, com dados de campo e petrografia. Embora sejam descritos na literatura como unidades independentes, trabalhos de campo e de mapeamento geológico na escala de 1:50.000 atestam a continuidade cartográfica entre o CJF, o CC e o CSV, que afloram na forma de escamas tectônicas, intensamente dobradas, intercaladas com sequências supracrustais geradas durante o evento Brasiliano (paragnaisses do Grupo Raposos), sendo ambos intrudidos por granitoides anatéticos Brasilianos (Suíte Salvaterra). Em relação às litologias observadas, é possível a separação, dentro do que anteriormente era abordado como CC e CSV, de escamas com ortogranulitos correlatos ao CJF, granulitos e gnaisses paraderivados (quase sempre com granada) correlatos ao Grupo Raposos, e de charnokitos e granitoides foliados com ou sem granada da Suíte Salvaterra. As escamas paleoproterozoicas afloram, sobretudo, em núcleos de anticlinais arrasadas, e os contatos com as demais unidades são tectônicos. Nestas escamas paleoproterozoicas afloram, predominantemente, ortogranulitos félsicos e máficos. Os ortogranulitos félsicos têm coloração cinza médio, cinza azulado ou esverdeado, são foliados (por vezes miloníticos), de granulação média a fina, sendo comum a ocorrência de porfiroblastos de Opx, Cpx e Pl. É típica a textura granonematoblástica e associações minerais de pico metamórfico com Opx ± Cpx + Pl + Kfs + Qz ± Op, e, por vezes, associações retrógradas com Hbl ± Bt. Os ortogranulitos máficos, por sua vez, apresentam, coloração cinza escuro, granulação fina a média. São foliados, com textura granonematoblástica e as associações de pico metamórfico (Opx ± Cpx + Pl ± Qz ± Kfs + OP), são em sua maior parte substituídas por Hbl e Bt retrógradas. Por fim, como conclusões preliminares, tem-se que os dados de campo e petrografia atestam a continuidade litoestrutural entre o CJF, CC e CSV, inliers remanescentes de um arco magmático paleoproterozoico retrabalhado durante o Ediacarano, em fácies granulito. A continuidade do projeto prevê a obtenção de dados de litogeoquímica, geocronologia U-Pb em zircão e de isótopos de Lu-Hf e Sm-Nd e Sr para o traçado de comparações e correlações mais robustas entre estes três complexos.

In this study, we characterized DArTseq-derived SNPs for species of Psidium, an important Neotropical genus within the family Myrtaceae. Nine Psidium species were used for the identification and characterization of an interspecific set of SNPs. The samples chosen represented a wide range of variation regarding agronomic traits and geographical origin. The samples were genotyped using the DarTseq methodology. This approach, associated with annotation analysis, generated a set of conserved, polymorphic, and possibly functional SNPs. Most of the SNPs in coding regions of Psidium were annotated for the gene ontology classes. We observed high interspecific diversity among species and considerable intraspecific genetic diversity in native species (P. cattleyanum, P. myrtoides, P. acidum, and P. oblongatum). Psidium guajava, a cultivated species, shows low diversity and shares genetic similarities with the tetraploid P. guineense. The group of markers selected in this study will contribute to the development of a panel of interspecific SNPs for Psidium. Our investigation will support further studies regarding genetic variability, diversity, phylogeny, cytogenetics, and other relationships among Psidium species, constituting essential information for the creation, conservation, management, and use of genetic resources in breeding programs.