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In Southeast Asia (SEA) fastidious fungi of the Ceratobasidium genus are associated with proliferation of sprouts and vascular necrosis in cacao and cassava, crops that were introduced from the tropical Americas to this region. Here, we report the isolation and in vitro culture of a Ceratobasidium sp. isolated from cassava with symptoms of witches' broom disease (CWBD), a devastating disease of this crop in SEA. The genome characterization using a hybrid assembly strategy identifies the fungus as an isolate of the species C. theobromae, the causal agent of vascular streak dieback of cacao in SEA. Both fungi have a genome size > 31 Mb (G+C content 49%), share > 98% nucleotide identity of the Internal Transcribed Spacer (ITS) and > 94% in genes used for species-level identification. Using RNAscope® we traced the pathogen and confirmed its irregular distribution in the xylem and epidermis along the cassava stem, which explains the obtention of healthy planting material from symptom-free parts of a diseased plant. These results are essential for understanding the epidemiology of CWBD, as a basis for disease management including measures to prevent further spread and minimize the risk of introducing C. theobromae via long-distance movement of cassava materials to Africa and the Americas.

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Cooking time is a crucial determinant of culinary quality of cassava roots and incorporating it into the early stages of breeding selection is vital for breeders. This study aimed to assess the potential of near-infrared spectroscopy (NIRS) in classifying cassava genotypes based on their cooking times. Five cooking times (15, 20, 25, 30, and 40 minutes) were assessed and 888 genotypes evaluated over three crop seasons (2019/2020, 2020/2021, and 2021/2022). Fifteen roots from five plants per plot, featuring diameters ranging from 4 to 7 cm, were randomly chosen for cooking analysis and spectral data collection. Two root samples (15 slices each) per genotype were collected, with the first set aside for spectral data collection, processed, and placed in two petri dishes, while the second set was utilized for cooking assessment. Cooking data were classified into binary and multiclass variables (CT4C and CT6C). Two NIRs devices, the portable QualitySpec® Trek (QST) and the benchtop NIRFlex N-500 were used to collect spectral data. Classification of genotypes was carried out using the K-nearest neighbor algorithm (KNN) and partial least squares (PLS) models. The spectral data were split into a training set (80%) and an external validation set (20%). For binary variables, the classification accuracy for cassava cooking time was notably high ( R C a l 2 ranging from 0.72 to 0.99). Regarding multiclass variables, accuracy remained consistent across classes, models, and NIR instruments (~0.63). However, the KNN model demonstrated slightly superior accuracy in classifying all cooking time classes, except for the CT4C variable (QST) in the NoCook and 25 min classes. Despite the increased complexity associated with binary classification, it remained more efficient, offering higher classification accuracy for samples and facilitating the selection of the most relevant time or variables, such as cooking time ≤ 30 minutes. The accuracy of the optimal scenario for classifying samples with a cooking time of 30 minutes reached R C a l 2   = 0.86 and R V a l 2 = 0.84, with a Kappa value of 0.53. Overall, the models exhibited a robust fit for all cooking times, showcasing the significant potential of NIRs as a high-throughput phenotyping tool for classifying cassava genotypes based on cooking time.

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There are few records for Telenomus dilophonotae Cameron, 1913 (Hymenoptera, Scelionidae) from South America. In Brazil, the first occurrence was reported in Bahia in rubber crops, Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell. - Arg., there parasitizing eggs of Erinnyis ello Linnaeus, 1758 (Lepidoptera, Sphingidae). It was also found parasitizing the same host in cassava, Manihot esculenta Crantz (Euphorbiaceae). This is the first record of occurrence of T. dilophonotae in the state of Paraná, parasitizing eggs of E. ello in areas of cassava production in the western region of Paraná, this being the southernmost record of the species. Here, photographs, the first sequence of DNA barcode of this species of parasitoid wasp, and a distribution map are provided.

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Cassava (Manihot esculenta Crantz) is a staple crop widely cultivated by small farmers in tropical countries. However, despite the low level of technology required for its management, it can be affected by several diseases, with anthracnose as the main threat. There is little information about the main species of Colletotrichum that infect cassava in Brazil. Thus, the objective of this work was to study the diversity, prevalence and virulence of Colletotrichum species that cause anthracnose in cassava leaves in northern Brazil. Twenty municipalities of the Pará and Tocantins states were selected, and leaves with symptoms were collected in those locations. Pure cultures were isolated in the laboratory. Species were identified using phylogenetic analyses of multiple loci, and their pathogenicity, aggressivity and virulence levels were assessed. Our results showed the greatest diversity of Colletotrichum associated with anthracnose in cassava plants of the "Formosa" cultivar in the Tocantins and Pará states. We determined the presence of Colletotrichum chrysophilum, C. truncatum, C. siamense, C. fructicola, C. plurivorum, C. musicola and C. karsti, with C. chrysophilum as the most aggressive and virulent. Our findings provide accurate identifications of species of Colletotrichum causing anthracnose in cassava crops, which are of great relevance for cassava breeding programs (e.g., the search for genotypes with polygenic resistance since the pathogen is so diverse) and for developing anthracnose management strategies that can work efficiently against species complexes of Colletotrichum.

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This work proposes the pyrolysis of the cassava plant shoot system biomass and a comprehensive chemical characterization of the resulting bio-oil. The highest yields of liquid products were obtained at 600 °C, with 12.6 % bio-oil (organic fraction), which presented the lowest total acid number of 65.7 mg KOH g-1. The bio-oil produced at 500 °C exhibited the highest total phenolic content of approximately 41 % GAE, confirmed by GC/MS analysis (33.8 % of the total area). FT-Orbitrap MS analysis found hundreds of oxygenated constituents in the bio-oils, belonging to the O2-7 classes, as well as nitrogen compounds from the Ny and OxNy classes. Higher pyrolysis temperatures resulted in more oxygenated phenolics (O4-7) undergoing secondary degradation and deoxygenation reactions, generating O2-3 compounds. Additional classes affected were O3-5N2-3, while O1-2N1 presented more stable compounds. These findings show that cassava bio-oils are promising sources of renewable chemicals.

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Cassava root-rot incited by soil-borne pathogens is one of the major diseases that reduces root yield. Although the use of resistant cultivars is the most effective method of management, the genetic basis for root-rot resistance remains poorly understood. Therefore, our work analyzed the transcriptome of two contrasting genotypes (BRS Kiriris/resistant and BGM-1345/susceptible) using RNA-Seq to understand the molecular response and identify candidate genes for resistance. Cassava seedlings (resistant and susceptible to root-rot) were both planted in infested and sterilized soil and samples from Initial-time and Final-time periods, pooled. Two controls were used: (i) seedlings collected before planting in infested soil (absolute control) and, (ii) plants grown in sterilized soil (mock treatments). For the differentially expressed genes (DEGs) analysis 23.912 were expressed in the resistant genotype, where 10.307 were differentially expressed in the control treatment, 15 DEGs in the Initial Time-period and 366 DEGs in the Final Time-period. Eighteen candidate genes from the resistant genotype were related to plant defense, such as the MLP-like protein 31 and the peroxidase A2-like gene. This is the first model of resistance at the transcriptional level proposed for the cassava × root-rot pathosystem. Gene validation will contribute to screening for resistance of germplasm, segregating populations and/or use in gene editing in the pursuit to develop most promising cassava clones with resistance to root-rot.

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Despite fungal diseases affecting the aerial parts of cassava (Manihot esculenta Crantz) and causing significant yield losses, there is a lack of comprehensive studies assessing resistance in the species' germplasm. This study aimed to evaluate the phenotypic diversity for resistance to anthracnose disease (CAD), blight leaf spot (BliLS), brown leaf spot (BLS), and white leaf spot (WLS) in cassava germplasm and to identify genotypes suitable for breeding purposes. A total of 837 genotypes were evaluated under field conditions across two production cycles (2021 and 2022). Artificial inoculations were carried out in the field, and data on yield and disease severity were collected using a standardized rating scale. The top 25 cassava genotypes were selected based on a selection index for disease resistance and agronomic traits. High environmental variability resulted in low heritabilities (h2) for CAD, WLS, and BLS (h2 = 0.42, 0.34, 0.29, respectively) and moderate heritability for BliLS (h2 = 0.51). While the range of data for disease resistance was narrow, it was considerably wider for yield traits. Cluster analysis revealed that increased yield traits and disease severity were associated with higher scores of the first and second discriminant functions, respectively. Thus, most clusters comprised genotypes with hybrid characteristics for both traits. Overall, there was a strong correlation among aerial diseases, particularly between BLS and BliLS (r = 0.96), while the correlation between CAD and other diseases ranged from r = 0.53 to 0.58. Yield traits showed no significant correlations with disease resistance. Although the mean selection differential for disease resistance was modest (between -2.31% and -3.61%), selection based on yield traits showed promising results, particularly for fresh root yield (82%), dry root yield (39%), shoot yield (49%), and plant vigor (26%). This study contributes to enhancing genetic gains for resistance to major aerial part diseases and improving yield traits in cassava breeding programs.

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The current study evaluated the effects of supplementing cassava root silage (CRS) to dairy cows grazing on Megathyrsus maximus cv Mombasa on nutrient intake and digestibility, as well as on milk production and composition. Ten primiparous Girolando cows with average body weight ± (SEM) of 373.45 ± (63.55) kg were used in a replicated 5 × 5 Latin square. Animals were subjected to five treatments: (I) grazing cows without supplementation (WCS); (II) grazing cows provided with 5 kg DM of supplement without CRS (0 g/kg DM of CRS) or including (III) 260, (IV) 520, and (V) 780 g/kg DM of CRS. Statistical analyses were performed using the PROC MIXED of SAS with significance at P < 0.05. Intake of neutral detergent fiber (NDF) and ether extract decreased (P < 0.01), while intake of non-fiber carbohydrates increased (P < 0.01), with increased CRS in the diets. Total DM intake and digestibility of DM, and digestibility of nutritional components were lower (P < 0.03) in WCS animals compared to supplemented animals, except for intake and digestibility of NDF, which was the opposite. Milk yield (MY) and fat corrected milk (FCM), as well as all milk components were unaffected (P > 0.05) by CRS inclusion. In contrast, MY, FCM, protein, lactose, casein, and non-fat milk solids (NFMS) were greater for animals that received supplementation (P < 0.05), compared to animals WCS. Milk fat and total dry extract (TMS) did not differ (P > 0.11) between two groups. In conclusion, CRS may be a potential corn meal replacer in the supplement of dairy cows under tropical conditions.

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OBJECTIVE: Determine the electrophoretic profiles of the extracts of Manihot esculenta, Actinidia Deliciosa and Persea Americana and their possible relationship with Latex-Fruit Syndrome. METHODS: Protein extracts of M. esculenta, P. Americana and A. Deliciosa were prepared through the processes of maceration and solvent extraction from plant samples. In the case of the avocado, a prior extraction by soxhlet was carried out to eliminate the fat. The extracts were vacuum filtered, dialyzed and finally lyophilized. Separation of proteins based on molecular weight was performed by SDS PAGE electrophoresis. The electrophoretic profiles obtained were compared with the allergenic proteins previously identified in the latex extract, in order to determine a possible relationship with Latex-Fruit Syndrome, depending on the molecular weight. RESULTS: The extracts of M. esculenta and P. Americana showed a wide range of protein fractions with molecular weights varying from 10 to 250 KD, finding that the region with the highest concentration of bands was between 20 and 89 KD, (60 and 65%), respectively. A 20-band profile was obtained for the M. esculenta extract (Figure 1), with seven bands sharing similar weights with the latex allergens (Hev b 1, Hev b 2, Hev b3, Hev b 4, Hev b 5, Hev b 6.03, Hev b 8 and Hev b 10) (3-5). For the P. Americana extract, 20 bands were also observed (Figure 2), seven of which presented approximate weights to the Latex allergens (Hev b 1, Hev b 2 Hev b 4 Hev b 6.01 Hev b 6.03 Hev b 8 , Hev b 10 Hev b 11 Hev b 14). The Kiwi extract showed two bands of 19.1 and 22.9 KD, with weights close to latex proteins (figure 3), (Hev b 3 and Hev b 6.01), and allergens (Act d 2 and Act d 6), reported in the literature for this fruit. CONCLUSIONS: When analyzing the relationship between the separated protein fractions and the latex allergens described in the literature, a possible association of 35% was found for the extracts of M. esculenta and P. Americana, and 10% for A. Delicious, with great relevance being the association found with the allergens Hev b 4, Hev b 2, Hev 8 and Hev b 11, which are involved in Latex-Fruit Syndrome. The electrophoretic profiles of the prepared extracts were determined and compared with the Latex allergens. This information generates a contribution for the development of new research and advances in the standardization of these extracts on a large scale and for their future use in diagnostic tests.

OBJETIVO: Determinar los perfiles electroforéticos de los extractos de Manihot esculenta, Actinidia deliciosa y Persea americana y su posible relación con el Síndrome de Látex ­ Fruta. MÉTODOS: Se prepararon extractos proteicos de M. esculenta, P. Americana y A. Deliciosa, a través de los procesos de macerado y extracción con solventes a partir muestras vegetales. En el caso del aguacate, se realizó una extracción previa por soxhlet, para eliminar la grasa. Los extractos se filtraron al vacío, se sometieron a diálisis y por último se liofilizaron. La separación de las proteínas en función del peso molecular se realizó mediante electroforesis SDS PAGE. Se compararon los perfiles electroforéticos obtenidos con las proteínas alergénicas previamente identificadas en el extracto de látex, con el fin de determinar una posible relación con el Síndrome de Látex-Fruta, en función del peso molecular. RESULTADOS: Los extractos de M. esculenta y P. americana mostraron una amplia gama de fracciones proteicas con pesos moleculares que varían desde 10 a 250 KD, encontrando que la región con mayor concentración de bandas se situó entre 20 y 89 KD, (60 y 65 %), respectivamente. Se obtuvo un perfil de 20 bandas para el extracto de M. esculenta (figura 1), con siete bandas que comparten pesos similares con los alérgenos del látex (Hev b 1, Hev b 2, Hev b3, Hev b 4, Hev b 5, Hev b 6.03, Hev b 8 y Hev b 10) (3-5). Para el extracto de P. americana, también se observaron 20 bandas (figura 2), siete de las cuales presentaron pesos aproximados a los alérgenos de Látex (Hev b 1, Hev b 2 Hev b 4 Hev b 6.01 Hev b 6.03 Hev b 8, Hev b 10 Hev b 11 Hev b 14). El extracto de Kiwi mostró dos bandas de 19,1 y 22,9 KD, con pesos cercanos a proteínas de látex (figura 3), (Hev b 3 y Hev b 6.01), y los alérgenos (Act d 2 y Act d 6), reportados en la literatura para esta fruta. CONCLUSIONES: Al analizar la relación existente entre las fracciones proteicas separadas y los alérgenos de los látex descritos en la literatura, se encontró una posible asociación del 35% para los extractos de M. esculenta y P. Americana, y del 10% para A. Deliciosa, siendo de gran relevancia la asociación encontrada con los alérgenos Hev b 4, Hev b 2, Hev 8 y Hev b 11, los cuales se encuentran implicados en el Síndrome de Látex-Fruto. Se lograron determinar los perfiles electroforéticos de los extractos elaborados y se compararon con los alérgenos del Látex. Está información genera un aporte para el desarrollo de nuevas investigaciones y avances en la estandarización de estos extractos a gran escala y para su uso futuro en pruebas diagnósticas.

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Background: Food allergy has considerably increased in recent years and this situation has been aggravated mainly by the consumption of more processed and complex foods, since minor or potentially allergenic foods are not required to be labeled. Manihot esculenta (cassava) is a widely consumed food in South America, Africa, and Asia and can be used in the production of flour and starch, as well as several other products. This root can cause allergic reactions with symptoms ranging from mild to severe. Methods: Thus, the aim of this study was the characterization of the immunogenic cassava proteins responsible for sensitizing patients allergic to it. Using a 2D-SDS-PAGE based proteomic approach, six proteins were identified, including Fructose Bisphosphate Aldolase (FBA). Recombinant FBA was produced in Expi293 cells and evaluated by immunoblotting with the serum of 10 individual study subjects. Results: Our results showed six cassava IgE-reactive proteins. From those, recombinant fructose bisphosphate aldolase (FBA) showed a positivity of 80% among tested sera, proving to be a highly sensitizing protein. Conclusion: The recombinant FBA molecule obtained in this study can be important for in vivo diagnostic assays, by producing more accurate results, and for desensitization protocols, in which the use of the isolated molecule produces more precise results by avoiding secondary sensitization. Trial registration: All patients signed a consent form approved by the internal ethics committee CAPPesq, Comissão de Ética para Análise de Projetos de Pesquisa do HC FMUSP (CAAE: 10420619.6.0000.0068).

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Several specialised insects can manipulate normal plant development to induce a highly organised structure known as a gall, which represents one of the most complex interactions between insects and plants. Thus far, the mechanism for insect-induced plant galls has remained elusive. To study the induction mechanism of insect galls, we selected the gall induced by Iatrophobia brasiliensis (Diptera: Cecidomyiidae) in cassava (Euphorbiaceae: Manihot esculenta Crantz) as our model. PCR-based molecular markers and deep metagenomic sequencing data were employed to analyse the gall microbiome and to test the hypothesis that gall cells are genetically transformed by insect vectored bacteria. A shotgun sequencing discrimination approach was implemented to selectively discriminate between foreign DNA and the reference host plant genome. Several known candidate insertion sequences were identified, the most significant being DNA sequences found in bacterial genes related to the transcription regulatory factor CadR, cadmium-transporting ATPase encoded by the cadA gene, nitrate transport permease protein (nrtB gene), and arsenical pump ATPase (arsA gene). In addition, a DNA fragment associated with ubiquitin-like gene E2 was identified as a potential accessory genetic element involved in gall induction mechanism. Furthermore, our results suggest that the increased quality and rapid development of gall tissue are mostly driven by microbiome enrichment and the acquisition of critical endophytes. An initial gall-like structure was experimentally obtained in M. esculenta cultured tissues through inoculation assays using a Rhodococcus bacterial strain that originated from the inducing insect, which we related to the gall induction process. We provide evidence that the modification of the endophytic microbiome and the genetic transformation of plant cells in M. esculenta are two essential requirements for insect-induced gall formation. Based on these findings and having observed the same potential DNA marker in galls from other plant species (ubiquitin-like gene E2), we speculate that bacterially mediated genetic transformation of plant cells may represent a more widespread gall induction mechanism found in nature.

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Genotype-environment interaction (GEI) presents challenges when aiming to select optimal cassava genotypes, often due to biased genetic estimates. Various strategies have been proposed to address the need for simultaneous improvements in multiple traits, while accounting for performance and yield stability. Among these methods are mean performance and stability (MPS) and the multi-trait mean performance and stability index (MTMPS), both utilizing linear mixed models. This study's objective was to assess genetic variation and GEI effects on fresh root yield (FRY), along with three primary and three secondary traits. A comprehensive evaluation of 22 genotypes was conducted using a randomized complete block design with three replicates across 47 distinct environments (year x location) in Brazil. The broad-sense heritability (H2) averaged 0.37 for primary traits and 0.44 for secondary traits, with plot-based heritability (hmÉ¡2) consistently exceeding 0.90 for all traits. The high extent of GEI variance (σÉ¡xe2) demonstrates the GEI effect on the expression of these traits. The dominant analytic factor (FA3) accounted for over 85% of the total variance, and the communality (ɧ) surpassed 87% for all traits. These values collectively suggest a substantial capacity for genetic variance explanation. In Cluster 1, composed of remarkably productive and stable genotypes for primary traits, genotypes BRS Novo Horizonte and BR11-34-69 emerged as prime candidates for FRY enhancement, while BRS Novo Horizonte and BR12-107-002 were indicated for optimizing dry matter content. Moreover, MTMPS, employing a selection intensity of 30%, identified seven genotypes distinguished by heightened stability. This selection encompassed innovative genotypes chosen based on regression variance index (Sdi2, R2, and RMSE) considerations for multiple traits. In essence, incorporating methodologies that account for stability and productive performance can significantly bolster the credibility of recommendations for novel cassava cultivars.

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Thematic collections (TCs), which are composed of genotypes with superior agronomic traits and reduced size, offer valuable opportunities for parental selection in plant breeding programs. Three TCs were created to focus on crucial attributes: root yield (CC_Yield), pest and disease resistance (CC_Disease), and root quality traits (CC_Root_quality). The genotypes were ranked using the best linear unbiased predictors (BLUP) method, and a truncated selection was implemented for each collection based on specific traits. The TCs exhibited minimal overlap, with each collection comprising 72 genotypes (CC_Disease), 63 genotypes (CC_Root_quality), and 64 genotypes (CC_Yield), representing 4%, 3.5%, and 3.5% of the total individuals in the entire collection, respectively. The Shannon-Weaver Diversity Index values generally varied but remained below 10% when compared to the entire collection. Most TCs exhibited observed heterozygosity, genetic diversity, and the inbreeding coefficient that closely resembled those of the entire collection, effectively retaining 90.76%, 88.10%, and 88.99% of the alleles present in the entire collection (CC_Disease, CC_Root_quality, and CC_Disease, respectively). A PCA of molecular and agro-morphological data revealed well-distributed and dispersed genotypes, while a discriminant analysis of principal components (DAPC) displayed a high discrimination capacity among the accessions within each collection. The strategies employed in this study hold significant potential for advancing crop improvement efforts.

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Cassava (Manihot esculenta Crantz) holds significant importance as one of the world's key starchy crop species. This study aimed to develop core collections by utilizing both phenotypic data (15 quantitative and 33 qualitative descriptors) and genotypic data (20,023 single-nucleotide polymorphisms) obtained from 1,486 cassava accessions. Six core collections were derived through two optimization strategies based on genetic distances: Average accession-to-nearest-entry and Average entry-to-nearest-entry, along with combinations of phenotypic and genotypic data. The quality of the core collections was evaluated by assessing genetic parameters such as genetic diversity Shannon-Weaver Index, inbreeding (Fis), observed (Ho), and expected (Hs) heterozygosity. While the selection of accessions varied among the six core collections, a seventh collection (consolidated collection) was developed, comprising accessions selected by at least two core collections. Most collections exhibited genetic parameters similar to the complete collection, except for those developed by the Average accession-to-nearest-entry algorithm. However, the variations in the maximum and minimum values of Ho, Hs, and Fis parameters closely resembled the complete collection. The consolidated collection and the collection constructed using genotypic data and the Average entry-to-nearest-entry algorithm (GenEN) retained the highest number of alleles (>97%). Although the differences were not statistically significant (above 5%), the consolidated collection demonstrated a distribution profile and mean trait values most similar to the complete collection, with a few exceptions. The Shannon-Weaver Index of qualitative traits exhibited variations exceeding ±10% when compared to the complete collection. Principal component analysis revealed that the consolidated collection selected cassava accessions with a more uniform dispersion in all four quadrants compared to the other core collections. These findings highlight the development of optimized and valuable core collections for efficient breeding programs and genomic association studies.

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Despite the economic and social importance, high-yielding cassava cultivars are only released after extensive research, mainly due to the low multiplication rate. This study aimed to assess the impact of using smaller-sized seed cuttings treated with agrochemicals (8MP) compared to the conventional planting size (16 cm) on genetic parameters, agronomic performance, and the ranking of cassava clones based on yield and growth attributes. The evaluation was carried out in clonal evaluation trial (CET), preliminary yield trial (PYT), and uniform yield trials (UYT). Additionally, a new selection scheme for cassava breeding programs was proposed. A total of 169 clones were evaluated, including 154 improved clones at different stages of selection and 15 local varieties used as checks. Field trials were conducted using both sizes of propagative material (8MP and 16 cm) in each phase of the breeding program. The data were analyzed using mixed models, considering the random effects of genotype and genotype-environment interaction (G×E) to determine variances and heritabilities. Bland-Altman concordance and correlation analysis of selection indices were employed to examine the consistency in the ranking of cassava clones using different seed cutting sizes. The distribution of variance components, heritabilities, means, and range of the 8MP and 16 cm trials in different phases of the cassava breeding program exhibited remarkable similarity, thereby enabling a comparative assessment of similar genetic effects. With a selection intensity of 30%, the concordance in clone ranking was 0.41, 0.57, and 0.85 in CET, PYT, and UYT trials, respectively, when comparing the selection based on 8MP and 16 cm trials. It is worth noting that the ranking of the top 15% remained largely unchanged. Based on the findings, proposed changes in the cassava selection scheme involve increasing the number of trials starting from the CET phase, early incorporation of G×E interaction, elimination of the PYT trial, reduction of the breeding cycle from 5 to 3 years, and a decrease in the time required for variety development from 11 to 9 years. These modifications are expected to lead to cost reduction and enhance the effectiveness of cassava breeding programs.

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Cassava is an essential tuber crop used to produce food, feed, and beverages. Whitefly pests, including Aleurothrixus aepim (Goeldi, 1886) (Hemiptera: Aleyrodidae), significantly affect cassava-based agroecosystems. Plant odours have been described as potential pest management tools, and the cassava clone M Ecuador 72 has been used by breeders as an essential source of resistance. In this study, we analysed and compared the volatile compounds released by this resistant clone and a susceptible genotype, BRS Jari. Constitutive odours were collected from young plants and analysed using gas chromatography-mass spectrometry combined with chemometric tools. The resistant genotype released numerous compounds with previously described biological activity and substantial amounts of the monoterpene (E)-ß-ocimene. Whiteflies showed non-preferential behaviour when exposed to volatiles from the resistant genotype but not the susceptible genotype. Furthermore, pure ocimene caused non-preferential behaviour in whiteflies, indicating a role for this compound in repellence. This report provides an example of the intraspecific variation in odour emissions from cassava plants alongside information on odorants that repel whiteflies; these data can be used to devise whitefly management strategies. A better understanding of the genetic variability in cassava odour constituents and emissions under field conditions may accelerate the development of more resistant cassava varieties.

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Introduction: In the French overseas department of French Guiana, in South America, nutrition therapy for the management of diabetes is based on French guidelines. However, this region is demographically diverse and includes several populations of Indigenous Peoples, Parikwene among others, also called Palikur. Due to socio-economical, cultural, and geographical differences, along with distinctions in the local food system, dietary recommendations, which many consider in the context of post-colonial power dynamics, are not well suited to local populations. In the absence of suitable recommendations, it is hypothesized that local populations will adapt their dietary practices considering diabetes as an emerging health problem. Methods: Seventy-five interviews were conducted with community members and Elders, as well as healthcare professionals and administrators providing services to the Parikwene population of Macouria and Saint-Georges de l'Oyapock communes. Data regarding the representation of cassava (Manihot esculenta Crantz) consumption and diabetes were collected via semi-structured interviews and participant observation (i.e., observation and participation in community activities), namely via participating in activities related to the transformation of cassava tubers at swidden and fallow fields. Results and Discussion: Parikwene have adapted the transformation of cassava tubers for their consumption in the management of diabetes.The importance of cassava tubers as a staple and core food to the Parikwene food system was established by identifying it as a cultural keystone species. Narratives illustrated conflicting perceptions regarding the implication of cassava consumption in the development of diabetes. Adaptations to the operational sequence involved in the transformation of cassava tubers led to the production of distinct cassava roasted semolina (i.e., couac), based on organoleptic properties (i.e., sweet, and acidic couac). Preferences for the consumption of acidic couac were grounded in the Parikwene knowledge system, as well as attention to diabetes related symptoms and glucometer readings. Conclusion: These results provide important insights related to knowledge, attitudes, and practices in developing locally and culturally adapted approaches to providing dietary recommendations in the treatment of diabetes.

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Phosphate fertilization of cassava cultivars leads to increased production costs that may be economically viable depending on the quantity used and the corresponding productivity. In this sense, the objective of the work was to analyse the economic viability of the irrigated cultivation of table cassava cultivars in response to the application of phosphorus doses in the Brazilian semiarid region. Two agricultural crops were conductedat the Experimental Farm Rafael Fernandes, Mossoró, RN, from June 2018 to April 2019 and from June 2019 to April 2020. The experimental design was in randomized blocks arranged in subdivided plots, with four replications. The doses of phosphorus (0, 60, 120, 180, and 240 kg ha-1of P2O5) were applied to the plots and the table cassava cultivars (Água Morna, BRS Gema de Ovo, Recife and Venâncio) arranged in the subplots. The total costs for one hectare of cultivation were estimated and the gross income, netincome, rate of return, and profitability index were calculated. The use of phosphatefertilizer was economically viable for the cassava cultivars studied in the two crops. The cultivars Água Morna, BRS Gema de Ovo, and Recife are the best cultivation options for the semiarid region of Rio Grande do Norteas they give high yields with the highest profitability. The Recife cultivar was the region's most profitable cultivation, with a profit ranging from R$ 40,331.07 ha-1to R$ 57,603.46 ha-1in both seasons,with an average recommendation of 120 kg ha-1of P2O5.(AU)

A adubação fosfatada de cultivares de mandioca leva ao aumento dos custos de produção que podem ser economicamente viáveis dependendo da quantidade utilizada e da respectiva produtividade. Nesse sentido, o objetivo dotrabalho foi analisar a viabilidade econômica do cultivo irrigado de cultivares de mandioca de mesa em resposta à aplicação de doses de fósforono semiárido brasileiro. Foram conduzidos duas safras agrícolas na Fazenda Experimental Rafael Fernandes, Mossoró, RN, nos meses de junho de 2018 a abril de 2019 e junho de 2019 a abril de 2020. O delineamento experimental foi em blocos casualizados dispostos em parcelas subdivididas, com quatro repetições. As doses de fósforo (0, 60, 120,180 e 240 kg ha-1de P2O5) foram aplicadas nas parcelas e as cultivares de mandioca de mesa (Água Morna, BRS Gema de Ovo, Recife e Venâncio) dispostas nas subparcelas. Estimaram-se os custos totais de um hectare de cultivo e calcularam-se a receita bruta,a receita líquida, a taxade retorno e o índice de lucratividade. O uso da adubação fosfatada mostrou-se economicamente viável para as cultivares de mandioca estudadas nas duas safras. As cultivares Água Morna, BRS Gema de Ovo e Recife são as melhores opções de cultivo para o semiárido do Rio Grande do Norte, pois apresentam altas produtividades com maior rentabilidade. A cultivar Recife foi o cultivo mais rentável da região, com rendimento variando de R$ 40.331,07 ha-1a R$ 57.603,46 ha-1nas duas safras,com recomendação média de120 kg ha-1de P2O5.(AU)

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Aim: The study evaluated the influence of tucupi on enamel surface roughness, microhardness, ultramorphology, and mass variation. Materials and Methods: Ninety healthy bovine incisors were divided into three experimental groups, according to the acidic challenge adopted, being: G1- tucupi, G2- cola-based soft drink, G3-distilled water. The enamel properties (surface roughness, microhardness, ultramorphology and mass variation) of all specimens were evaluated at times T0 (before any intervention), T10 (10 days after the proposed treatments), T20 (20 days after the proposed treatments) and T30 (30 days after the proposed treatments). After confirming the normality of the data (Shapiro-Wilk test), a two-way ANOVA (α = 5%) was performed, followed by Sidak post-test, with results described as mean and standard deviation. Results: The roughness means increased for all tested groups, with no statistical difference only in G3 for all evaluated times. Microhardness of all groups showed a significant decrease over the time, with the lowest average observed in G1 in T30. Considering enamel mass variation, the lowest average was in G2 at time T3, with no statistical difference only in G3 (distilled water) over the time. Regarding ultramorphology (scanning electron microscopy - SEM), only groups G1 and G2, that were exposed to acidic challenges, showed disorganization of the enamel surface layer. Conclusion: It was possible to conclude that tucupi has low pH and high titratable total acidity, being able to gradually decrease enamel microhardness, increasing surface roughness and causing loss of dental enamel.

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The knowledge of ruminal degradation kinetics of forage cactus-based diets associated with Euphorbiaceae species of the genus Manihot assist in understanding nutrient quality and use, contributing to the indication of combinations of these ingredients in ruminant diets. This study aimed to evaluate the in situ ruminal degradability of diets with increasing association of forage cactus Elephant Ear (MEE) and pornunça (Manihot sp.) silage, as well as to analyze and evaluate the indigestible neutral detergent fiber (FDNi) content of forage cactus MEE and pornunça silage. The treatments consisted of diets with cactus pear associated with pornunça silage in the roughage portion in the proportions of 375, 250, 125 and 0 g kg-1 of DM. The feed was composed of 50% roughage and 50% concentrate of dry matter. Incubation times of 0, 6, 12, 24, 48, 96, and 144 hours were evaluated for the ingredients and 0, 2, 4, 6, 8, 12, 24, 48, 72, and 96 hours for the diets. Incubation to obtain the iNDF was given for 288 hours. The experimental design consisted of randomized blocks, with three replications. Regarding roughage ingredients, MEE showed higher average disappearance, potential degradability (PD), and effective degradability (ED) in relation to pornunça silage, as well as lower NDFi content. The proportion of 375 g kg-1 MEE and 125 g kg-1 pornunça silage provided higher fractions a, b, and c, increasing ED considering the three passage rates, with higher PD. In conclusion, the association between MEE and pornunça silage at a proportion of 375 g kg-1 MEE and125g kg-1 pornunça silage of the roughage portion increases the in situ degradability of dry matter, crude protein, and neutral detergent fiber.

O conhecimento da cinética de degradação ruminal de dietas compostas por palma-forrageira associadas com espécies de Euphorbiaceae do gênero Manihot auxiliam na compreensão da qualidade e aproveitamento dos nutrientes, com contribuição para a indicação de combinações destes ingredientes em dietas para ruminantes. Objetivou-se avaliar a degradabilidade ruminal in situ de dietas com crescente associação de palma-forrageira Orelha de Elefante Mexicana (OEM) e silagem de pornunça (Manihot sp.), assim como, avaliar o teor de fibra em detergente neutro indigestível (FDNi) da palma OEM e da silagem de pornunça. Os tratamentos consistiram em dietas com palma forrageira associada à silagem de pornunça na porção volumosa nas proporções de 375, 250, 125 e 0 g kg-1 na MS. A dieta foi composta por 50% de volumoso e 50% de concentrado da matéria seca. Foram avaliados os tempos de incubação de 0, 6,12, 24, 48, 96 e 144 para os ingredientes e 0, 2, 4, 6, 8 ,12, 24, 48, 72 e 96 para as dietas. A incubação para a obtenção do FDNi foi realizada por 288 horas. O delineamento experimental utilizado foi em blocos casualizados, com três repetições. Quanto aos ingredientes volumosos, a palma OEM apresentou maior desaparecimento médio, degradabilidade potencial (DP) e degradabilidade efetiva (DE) em relação à silagem de pornunça, bem como menor teor de FDNi. A proporção de 375 g kg-1 OEM e 125 g kg-1 de silagem de pornunça propiciou maiores frações a, b e c, atuando no aumento da DE considerando as três taxas de passagem, com maior DP. Conclui-se que à associação de palma OEM e silagem de pornunça na proporção de 375 g kg-1 OEM e 125 g kg-1 da silagem de pornunça da porção volumosa aumenta a degradabilidade in situ da matéria seca, proteína bruta e fibra em detergente neutro.

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