Estimation of diffusion coefficients during carrots cooking in arsenious solution at different temperatures.

This study is based on an investigation of the transport phenomenon, specifically the quantification of arsenic diffusion in carrots within a temperature range of 89 °C-99 °C using a thin plate model. Studying the diffusion of arsenic in carrots is important due to its toxicity, as it can concentrate during cooking. The World Health Organization considers arsenic as one of the ten chemical substances of public health concern. In this study, biennial hybrid carrots of the Nantesa variety were cooked whole with their epidermis in an aqueous solution containing diarsenic trioxide with an As concentration of 5 mgL-1 at 89 °C, 94 °C, and 99 °C. The cooking times of the carrots at different temperatures were based on a specific degree of tenderness, with a value of ≤3 kg m-2. The evaluated data showed consistency with increasing temperature. The calculated effective diffusion coefficients at temperatures of 89 °C, 94 °C, and 99 °C were 5.84E-09 m2s-1, 1.08E-08 m2s-1, and 2.51E-08 m2s-1 for the flesh (DL), and 1.601E-11 m2s-1, 2.15E-11 m2s-1, and 4.39E-11 m2s-1 for the epidermis (DE), respectively. The activation energy for diffusion was determined to be 159.54 kJmol-1 for the and 110.68 kJmol-1 for the epidermis. Similar behaviours were observed in different radial positions of the carrot, where the arsenic content decreased from the periphery to the centre, consistent with studies on diffusion phenomena with other solutes in food. The novelty was the detailed quantification of arsenic diffusion in the Nantes-type hybrid carrot matrix. This study is limited to a specific concentration of 5 mgL-1 of arsenic solution. The findings of this study may have significant implications for public health and food safety.

Introgression and persistence of cultivar alleles in wild carrot (Daucus carota) populations in the United States.

PREMISE: Cultivated species and their wild relatives often hybridize in the wild, and the hybrids can survive and reproduce in some environments. However, it is unclear whether cultivar alleles are permanently incorporated into the wild genomes or whether they are purged by natural selection. This question is key to accurately assessing the risk of escape and spread of cultivar genes into wild populations. METHODS: We used genomic data and population genomic methods to study hybridization and introgression between cultivated and wild carrot (Daucus carota) in the United States. We used single nucleotide polymorphisms (SNPs) obtained via genotyping by sequencing for 450 wild individuals from 29 wild georeferenced populations in seven states and 144 cultivars from the United States, Europe, and Asia. RESULTS: Cultivated and wild carrot formed two genetically differentiated groups, and evidence of crop-wild admixture was detected in several but not all wild carrot populations in the United States. Two regions were identified where cultivar alleles were present in wild carrots: California and Nantucket Island (Massachusetts). Surprisingly, there was no evidence of introgression in some populations with a long-known history of sympatry with the crop, suggesting that post-hybridization barriers might prevent introgression in some areas. CONCLUSIONS: Our results provide support for the introgression and long-term persistence of cultivar alleles in wild carrots populations. We thus anticipate that the release of genetically engineered (GE) cultivars would lead to the introduction and spread of GE alleles in wild carrot populations.

Characterization of Purple Carrot Germplasm for Antioxidant Capacity and Root Concentration of Anthocyanins, Phenolics, and Carotenoids.

The present study characterized a genetically and phenotypically diverse collection of 27 purple and two non-purple (one orange and one yellow) carrot accessions for concentration of root anthocyanins, phenolics, and carotenoids, and antioxidant capacity estimated by four different methods (ORAC, DPPH, ABTS, FRAP), in a partially replicated experimental design comprising data from two growing seasons (2018 and 2019). Broad and significant (p < 0.0001) variation was found among the accessions for all the traits. Acylated anthocyanins (AA) predominated over non-acylated anthocyanins (NAA) in all the accessions and years analyzed, with AA accounting for 55.5-100% of the total anthocyanin content (TAC). Anthocyanins acylated with ferulic acid and coumaric acid were the most abundant carrot anthocyanins. In general, black or solid purple carrots had the greatest TAC and total phenolic content (TPC), and the strongest antioxidant capacities, measured by all methods. Antioxidant capacity, estimated by all methods, was significantly, positively, and moderately-to-strongly correlated with the content of all individual anthocyanins pigments, TAC, and TPC, in both years (r = 0.59-0.90, p < 0.0001), but not with the carotenoid pigments lutein and ß-carotene; suggesting that anthocyanins and other phenolics, but not carotenoids, are major contributors of the antioxidant capacity in purple carrots. We identified accessions with high concentration of chemically stable AA, with potential value for the production of food dyes, and accessions with relatively high content of bioavailable NAA that can be selected for increased nutraceutical value (e.g., for fresh consumption).

TPP-chitosomes as potential encapsulation system to protect carotenoid-rich extract obtained from carrot by-product: A comparison with liposomes and chitosomes.

The objectives of this study were to extract bioactive compounds from carrot by-products and evaluate their chemical stability after encapsulation in liposomes (L) coated either with chitosan (Ch) or using sodium tripolyphosphate for chitosan complexation (TPP-Ch). The main compounds quantified in this study were carotenoids and total phenolic compounds, which reached encapsulation efficiencies higher than 75%. The TPP-Ch charged with carrot extract showed greater particle size (90.5 nm) and zeta potential (+22 mV) than vesicles without coating (68.0 nm and -2 mV, respectively), indicating that liposomes were successfully coated with chitosan. Regarding results of the carotenoid's encapsulated stability, TPP-Ch particles were more efficient preventing their degradation in all the experimental conditions studied (40 and 70 °C). It is significant that loaded TPP-Ch particles demonstrated similar results for the stability of carotenoid-rich extracts in ethanol, which would therefore be suitable for application in food industry or any aqueous matrices.

Carrot protoplasts as a suitable method for protein subcellular localization.

Carrot (Daucus carota) is a useful plant model for the study of carotenoid biosynthesis, specifically in roots which are enriched in carotenoids. Carrot genome and transcriptome sequences, complemented by optimized methods for carrot transformation, contribute to a comprehensive toolbox for exploring pathway regulation. To expand the repertoire of tools available for the study of D. carota, we present protocols for the isolation of protoplasts from D. carota cell suspension cultures and polyethylene glycol (PEG)-mediated transformation. To obtain carrot protoplasts, in vitro somatic embryogenesis from epicotyls is induced. The somatic embryogenic tissue that develops is transferred to liquid medium to obtain a suspension of cells which are homogenized and incubated with cell-wall degrading enzymes to release protoplasts. For transfection, protoplasts are incubated with a plasmid encoding a protein of interest prior to examination of protein localization by light microscopy. As an example, we demonstrate nuclear localization of a carrot transcription factor, DcAREB3.

Vernalization Requirement, but Not Post-Vernalization Day Length, Conditions Flowering in Carrot (Daucus carota L.).

Carrots require a certain number of cold hours to become vernalized and proceed to the reproductive stage, and this phenomenon is genotype-dependent. Annual carrots require less cold than biennials to flower; however, quantitative variation within annuals and biennials also exists, defining a gradient for vernalization requirement (VR). The flowering response of carrots to day length, after vernalization has occurred, is controversial. This vegetable has been described both as a long-day and a neutral-day species. The objective of this study was to evaluate flowering time and frequency in response to different cold treatments and photoperiod regimes in various carrot genotypes. To this end, three annual genotypes from India, Brazil, and Pakistan, and a biennial carrot from Japan, were exposed to 7.5 °C during 30, 60, 90, or 120 days, and then transferred to either long day (LD) or short day (SD) conditions. Significant variation (p < 0.05) among the carrot genotypes and among cold treatments were found, with increased flowering rates and earlier onset of flowering being associated with longer cold exposures. No significant differences in response to photoperiod were found, suggesting that post-vernalization day length does not influence carrot flowering. These findings will likely impact carrot breeding and production of both root and seed, helping in the selection of adequate genotypes and sowing dates to manage cold exposure and day-length for different production purposes.

Treatment with Argovit® Silver Nanoparticles Induces Differentiated Postharvest Biosynthesis of Compounds with Pharmaceutical Interest in Carrot (Daucus carota L.).

The global market for plant-derived bioactive compounds is growing significantly. The use of plant secondary metabolites has been reported to be used for the prevention of chronic diseases. Silver nanoparticles were used to analyze the content of enhancement phenolic compounds in carrots. Carrot samples were immersed in different concentrations (0, 5, 10, 20, or 40 mg/L) of each of five types of silver nanoparticles (AgNPs) for 3 min. Spectrophotometric methods measured the total phenolic compounds and the antioxidant capacity. The individual phenolic compounds were quantified by High Performance Liquid Chromatography (HPLC) and identified by -mass spectrometry (HPLC-MS). The five types of AgNPs could significantly increase the antioxidant capacity of carrots' tissue in a dose-dependent manner. An amount of 20 mg/L of type 2 and 5 silver nanoparticle formulations increased the antioxidant capacity 3.3-fold and 4.1-fold, respectively. The phenolic compounds that significantly increased their content after the AgNP treatment were chlorogenic acid, 3-O-caffeoylquinic acid, and 5'-caffeoylquinic acid. The increment of each compound depended on the dose and the type of the used AgNPs. The exogenous application of Argovit® AgNPs works like controlled abiotic stress and produces high-value secondary bioactive compounds in carrot.

Genetic and Transcription Profile Analysis of Tissue-Specific Anthocyanin Pigmentation in Carrot Root Phloem.

In purple carrots, anthocyanin pigmentation can be expressed in the entire root, or it can display tissue specific-patterns. Within the phloem, purple pigmentation can be found in the outer phloem (OP) (also called the cortex) and inner phloem (IP), or it can be confined exclusively to the OP. In this work, the genetic control underlying tissue-specific anthocyanin pigmentation in the carrot root OP and IP tissues was investigated by means of linkage mapping and transcriptome (RNA-seq) and phylogenetic analyses; followed by gene expression (RT-qPCR) evaluations in two genetic backgrounds, an F2 population (3242) and the inbred B7262. Genetic mapping of 'root outer phloem anthocyanin pigmentation' (ROPAP) and inner phloem pigmentation (RIPAP) revealed colocalization of ROPAP with the P1 and P3 genomic regions previously known to condition pigmentation in different genetic stocks, whereas RIPAP co-localized with P3 only. Transcriptome analysis of purple OP (POP) vs. non-purple IP (NPIP) tissues, along with linkage and phylogenetic data, allowed an initial identification of 28 candidate genes, 19 of which were further evaluated by RT-qPCR in independent root samples of 3242 and B7262, revealing 15 genes consistently upregulated in the POP in both genetic backgrounds, and two genes upregulated in the POP in specific backgrounds. These include seven transcription factors, seven anthocyanin structural genes, and two genes involved in cellular transport. Altogether, our results point at DcMYB7, DcMYB113, and a MADS-box (DCAR_010757) as the main candidate genes conditioning ROPAP in 3242, whereas DcMYB7 and MADS-box condition RIPAP in this background. In 7262, DcMYB113 conditions ROPAP.

Daucus carota DcPSY2 and DcLCYB1 as Tools for Carotenoid Metabolic Engineering to Improve the Nutritional Value of Fruits.

Carotenoids are pigments with important nutritional value in the human diet. As antioxidant molecules, they act as scavengers of free radicals enhancing immunity and preventing cancer and cardiovascular diseases. Moreover, α-carotene and ß-carotene, the main carotenoids of carrots (Daucus carota) are precursors of vitamin A, whose deficiency in the diet can trigger night blindness and macular degeneration. With the aim of increasing the carotenoid content in fruit flesh, three key genes of the carotenoid pathway, phytoene synthase (DcPSY2) and lycopene cyclase (DcLCYB1) from carrots, and carotene desaturase (XdCrtI) from the yeast Xanthophyllomyces dendrorhous, were optimized for expression in apple and cloned under the Solanum chilense (tomatillo) polygalacturonase (PG) fruit specific promoter. A biotechnological platform was generated and functionally tested by subcellular localization, and single, double and triple combinations were both stably transformed in tomatoes (Solanum lycopersicum var. Microtom) and transiently transformed in Fuji apple fruit flesh (Malus domestica). We demonstrated the functionality of the S. chilense PG promoter by directing the expression of the transgenes specifically to fruits. Transgenic tomato fruits expressing DcPSY2, DcLCYB1, and DcPSY2-XdCRTI, produced 1.34, 2.0, and 1.99-fold more total carotenoids than wild-type fruits, respectively. Furthermore, transgenic tomatoes expressing DcLCYB1, DcPSY2-XdCRTI, and DcPSY2-XdCRTI-DcLCYB1 exhibited an increment in ß-carotene levels of 2.5, 3.0, and 2.57-fold in comparison with wild-type fruits, respectively. Additionally, Fuji apple flesh agroinfiltrated with DcPSY2 and DcLCYB1 constructs showed a significant increase of 2.75 and 3.11-fold in total carotenoids and 5.11 and 5.84-fold in ß-carotene, respectively whereas the expression of DcPSY2-XdCRTI and DcPSY2-XdCRTI-DcLCYB1 generated lower, but significant changes in the carotenoid profile of infiltrated apple flesh. The results in apple demonstrate that DcPSY2 and DcLCYB1 are suitable biotechnological genes to increase the carotenoid content in fruits of species with reduced amounts of these pigments.

Desarrollo de una carne de hamburguesa de pechuga de pollo con adición de fibra y reducción de grasa / The Development of Hamburger Meat Made with Chicken Breast, Added Fiber and Reduced Fat

Resumen Antecedentes: la asociación del alto consumo de carnes rojas procesadas con el cáncer colorrectal hace que los consumidores empiecen a demandar productos cárnicos con un perfil nutricional mejorado. Objetivo: diseñar una carne de hamburguesa comercializable, a base de pechuga de pollo, fuente de fibra y baja en grasa con buena aceptación por los consumidores. Materiales y métodos: con base en una formulación estándar de hamburguesa, se hicieron tres formulaciones con adición de fibra como reemplazante de grasa: F1 contenía fibra de cidra (Sechium edule); F2, de zanahoria (Daucus carota); y F3, de inulina. Se calculó la composición nutricional teórica y se realizó una prueba de aceptación por consumidores con una escala de nueve puntos. Resultados: la formulación más aceptada y con mayor contenido de fibra fue la que contenía inulina, con un puntaje de 7,7±1,4 y diferencias significativas, según la prueba T3 de Dunett, con las formulaciones F2 (p=0,001) y F1 (p=0,000), cuyos promedios de aceptación fueron similares: 6,0±2,5 puntos para F2 y 5,9±2,2 para F1 (p=0,931). Las formulaciones con fibra contenían menos grasa y calorías que la formulación control. Conclusión: es posible lograr derivados cárnicos con reducción del contenido de grasa y aporte de fibra sensorialmente aceptados.

Abstract Background: The association between increased consumption of processed red meat and colorectal cancer has driven the demand for meat products with improved nutritional profiles. Objective: To design commercialized hamburger meat that contains chicken breast as the base, fiber, reduced fat, and is accepted by consumers. Materials and Methods: Three formulations were created with a standard hamburger base and additional fiber as a fat replacement: F1 contained fiber from citron (Sechium edule); F2, from carrots (Daucus carota); and F3 from inulin. The theoretical nutritional composition was calculated and a consumer acceptance test was performed on a scale of nine points. Results: The most accepted formulation by consumers with the highest fiber content was the hamburger containing inulin, rated at 7.7±1.4 points. According to the Dunett T3 test, significant differences were reached by F1 (p=0.000) and F2 (p=0.001). They also had similar acceptance averages: F1 (5.9±2.2 points; p=0,000) and F2 (6.0±2.5 points; p=0.001) (p=0.931). The formulations containing added fiber were lowest in fat and calories when compared to the control formulation. Conclusion: It is possible to achieve meat derivatives with reduced fat and added fiber that are sensorily accepted by consumers.

Carotenoids from mamey (Pouteria sapota) and carrot (Daucus carota) increase the oxidative stress resistance of Caenorhabditis elegans.

Carotenoids are natural pigments and antioxidants found in fruits and vegetables such as carrot, tomato, orange, mango, yellow corn, pumpkin, and mamey. In this study, we evaluated the antioxidant potential of mamey (Pouteria sapota) carotenoids and compared them to carrot (Daucus carota) carotenoids. The carotenoids were extracted from mamey and carrot, and their antioxidant capacity were determined via in vitro (ABTS method) and in vivo assays (resistance against oxidative stress in Caenorhabditis elegans). The carotenoid contents in mamey and carrot were 4.42 ± 0.12 and 5.47 ± 0.04 mg ß-carotene/100 g, respectively. Despite the differences between the carotenoid contents in both products (p < 0.05), the in vitro antioxidant capacity results showed no significant differences between the extracts (p > 0.05). The mamey and carrot carotenoid extracts decreased the oxidative damage in C. elegans by 20-30% and 30-40%, respectively. Both extracts increased the resistance and enhanced the survival of the nematodes, and showed better effects than pure ß-carotene, probably owing to the complex mixture in the carotenoid extracts. These results suggest that mamey is a good alternative source of carotenoids and that it protects against oxidative stress in C. elegans. The protective effect of mamey carotenoids was similar to the effect of carrot carotenoids.

Vigor de sementes de cenoura recobertas com bioestimulante de Solieria filiformis / Vigor of carrot seeds covered with Solieria filiformis biostimulant

Para garantir sementes com alta qualidade fisiológica resultando em um estande de plantas uniforme, resiliente e tolerante a estresses abióticos, procedimentos que possam melhorar o potencial da semente, como a utilização de bioestimulantes, necessitam ser estudados. O objetivo deste trabalho foi verificar o efeito do recobrimento de sementes de diferentes cultivares de cenoura com bioestimulante a base da alga Solieria filiformis na germinação de sementes e desenvolvimento de plântulas em estresse térmico. O experimento foi conduzido em delineamento experimental inteiramente casualizado, com esquema fatorial 4 x 4 (cultivares e doses), com cinco repetições. Foram utilizadas sementes de cenoura das cultivares Brasília, Danvers, Esplanada e Planalto, e o recobrimento das sementes foi realizado com as doses de 0, 2, 4 e 8 mL.L-1 de bioestimulante. Após o recobrimento as sementes foram submetidas as seguintes avaliações: porcentagem e velocidade de germinação, comprimento de plântulas, massa seca de plântulas e envelhecimento acelerado. Os resultados obtidos foram submetidos à análise de variância e à análise de regressão (doses) e teste de Tukey (cultivares). Não houve melhorias na germinação e crescimento de plântulas de cenoura em condições adequadas de temperatura, contudo observou-se maior velocidade de germinação na temperatura de 30°C para a cultivar...

To guarantee seeds with high physiological quality, resulting in a uniform plant stand, resilient and tolerant to abiotic stresses, procedures that can improve the seed potential, such as the use of biostimulant, need to be studied. The objective of this work was to evaluate the effect of seed coating of different carrot cultivars with biostimulant based on the algae Solieria filiformis on seed germination and seedling development under thermal stress. The experiment was conducted in a completely randomized design, with a 4 x 4 factorial scheme (cultivars and doses), with five replications. Carrot seeds from the cultivars Brasília, Danvers, Esplanada and Planalto were used, and the seeds were covered with doses of 0, 2, 4 and 8 mL.L-1 of biostimulant. After covering and sterilizing, the seeds were submitted to evaluations of: percentage and germination speed, seedling length, seedling dry mass and accelerated aging. The results were submitted to analysis of variance and regression analysis (doses) and Tukey test (cultivars). There were no improvements in the germination and growth of carrot seedlings under adequate temperature conditions, however there was a higher germination speed at a temperature of 30°C for the Brasilia cultivar, an increase in the shoot and root growth at seed temperature 30 °C for Esplanada and Planalto cultivars and dry root mass for...

Vigor de sementes de cenoura recobertas com bioestimulante de Solieria filiformis / Vigor of carrot seeds covered with Solieria filiformis biostimulant

Para garantir sementes com alta qualidade fisiológica resultando em um estande de plantas uniforme, resiliente e tolerante a estresses abióticos, procedimentos que possam melhorar o potencial da semente, como a utilização de bioestimulantes, necessitam ser estudados. O objetivo deste trabalho foi verificar o efeito do recobrimento de sementes de diferentes cultivares de cenoura com bioestimulante a base da alga Solieria filiformis na germinação de sementes e desenvolvimento de plântulas em estresse térmico. O experimento foi conduzido em delineamento experimental inteiramente casualizado, com esquema fatorial 4 x 4 (cultivares e doses), com cinco repetições. Foram utilizadas sementes de cenoura das cultivares Brasília, Danvers, Esplanada e Planalto, e o recobrimento das sementes foi realizado com as doses de 0, 2, 4 e 8 mL.L-1 de bioestimulante. Após o recobrimento as sementes foram submetidas as seguintes avaliações: porcentagem e velocidade de germinação, comprimento de plântulas, massa seca de plântulas e envelhecimento acelerado. Os resultados obtidos foram submetidos à análise de variância e à análise de regressão (doses) e teste de Tukey (cultivares). Não houve melhorias na germinação e crescimento de plântulas de cenoura em condições adequadas de temperatura, contudo observou-se maior velocidade de germinação na temperatura de 30°C para a cultivar...(AU)

To guarantee seeds with high physiological quality, resulting in a uniform plant stand, resilient and tolerant to abiotic stresses, procedures that can improve the seed potential, such as the use of biostimulant, need to be studied. The objective of this work was to evaluate the effect of seed coating of different carrot cultivars with biostimulant based on the algae Solieria filiformis on seed germination and seedling development under thermal stress. The experiment was conducted in a completely randomized design, with a 4 x 4 factorial scheme (cultivars and doses), with five replications. Carrot seeds from the cultivars Brasília, Danvers, Esplanada and Planalto were used, and the seeds were covered with doses of 0, 2, 4 and 8 mL.L-1 of biostimulant. After covering and sterilizing, the seeds were submitted to evaluations of: percentage and germination speed, seedling length, seedling dry mass and accelerated aging. The results were submitted to analysis of variance and regression analysis (doses) and Tukey test (cultivars). There were no improvements in the germination and growth of carrot seedlings under adequate temperature conditions, however there was a higher germination speed at a temperature of 30°C for the Brasilia cultivar, an increase in the shoot and root growth at seed temperature 30 °C for Esplanada and Planalto cultivars and dry root mass for...(AU)

Yield and phosphorus use efficiency of carrot cultivars

Phosphate fertilization is indispensable for carrot cultivation, as it contributes to plant development, formation of marketable roots and higher yields. In this context, the objective of this study was to evaluate the production and nutritional efficiency of carrot cultivars under phosphate fertilization. The experiments were carried out from July to November 2016 and from June to October 2017, at the Rafael Fernandes experimental farm, District of Alagoinha, Mossoró, RN, Brazil. The experimental design was in randomized blocks, in a 4×4 factorial scheme with 4 replicates. The treatments consisted of the combination of carrot cultivars (Brasília, Planalto, Suprema and Nativa) with phosphorus (P) doses (0, 90, 180 and 270 kg ha-1 P2O5). The characteristics analyzed were: P content in the diagnostic leaf, plant dry matter, plant height, marketable and total yields, and the classification of cultivars for efficiency and response to phosphate fertilization. The increments promoted by phosphate fertilization were 64% in plant height, 444% in dry matter and 284% in marketable yield. The maximum marketable yield was obtained with doses from 186.8 to 243.5 kg ha-1, depending on the cultivar. The Native cultivar was classified as more efficient in the use of P.

Sustainability of carrot-cowpea intercropping systems through optimization of green manuring and spatial arrangements / Sustentabilidade de sistemas consorciados de cenoura e feijão-caupi por meio da otimização da adubação verde e arranjos espaciais

One of the biggest challenges in intercropping of two or more crops is to maintain their productivity as that of their sole counterparts. In order to obtain sustainable intercropping systems in a semi-arid environment, this study evaluated the agro-economic advantage and sustainability of intercropped systems of carrot and cowpea, optimizing the green manuring and spatial arrangements. Experiments were conducted in the period from July to October 2017 and 2018, using a randomized complete block design with the treatments arranged in a 4 x 3 factorial scheme, with four replications. Treatments included four amounts of M. aegyptia incorporated into the soil (20, 35, 50, and 65 t ha-1 on dry basis) with three spatial arrangements (2:2, 3:3, and 4:4) between the components cultures formed from cowpea rows alternated with carrot rows. The agro-economic advantage indices evaluated in the intercropping systems were: land equivalent ratio (LER), area-time equivalent ratio (ATER), score of the canonical variable (Z), actual yield loss (AYL), intercropping advantage (IA), gross income (GI), net income (NI), rate of return (RR), and profit margin (PM). The highest agro-economic advantages of the carrot and cowpea intercropping were obtained for LER, ATER, NI, and RR of 2.60, 4.16, US$ 8,720.99 ha-1, and US$ 2.21, respectively, for M. aegyptia biomass amounts of 46.42, 47.82, 32.60 and 31.51t ha-1 added to the soil. The 2: 2 spatial arrangement was the one with the best productive performance, with higher net income and rate of return in the intercropping of carrot-cowpea.(AU)

Um dos maiores desafios no consórcio de duas ou mais culturas é manter sua produtividade como a de suas únicas contrapartes. Com o objetivo de obter sistemas de consórcio sustentáveis ​​em ambiente semiárido, este estudo avaliou vantagem agroeconômica e a sustentabilidade de sistemas consorciados de cenoura e feijão-caupi, otimizando a adubação verde e os arranjos espaciais. Experimentos foram conduzidos no período de julho a outubro de 2017 e 2018, em delineamento de blocos ao acaso, com os tratamentos dispostos em esquema fatorial 4 x 3, com quatro repetições. Os tratamentos incluíram quatro quantidades de M. aegyptia incorporadas ao solo (20, 35, 50 e 65 t ha-1 em base seca) com três arranjos espaciais (2: 2, 3: 3 e 4: 4) entre as culturas componentes formadas a partir de fileiras de feijão-caupi alternadas com fileiras de cenoura. Os índices de vantagem agroeconômica avaliados nos sistemas de consorciação foram: índice de uso eficiente da terra (UET), razão de área equivalente no tempo (RAET), escore da variável canônica (Z), perda de rendimento real (PRR), vantagem do consórcio (VC), renda bruta (RB), renda líquida (RL), taxa de retorno (TR) e margem de lucro (ML). As maiores vantagens agroeconômicas do consórcio de cenoura e feijão-caupi foram obtidas para UET, RAET, RL e TR de 2,60, 4,16, US$ 8.720,99 ha-1 e US$ 2,21, respectivamente, para as quantidades de biomassa de M. aegyptia de 46,42, 47,82, 32,60 e 31,51 t ha-1, adicionadas ao solo. O arranjo espacial 2: 2 foi o de melhor desempenho produtivo, com maior receita líquida e taxa de retorno no consórcio entre feijão-caupi e cenoura.(AU)

Distribution of Meloidogyne species in carrot in Brazil / Distribuição de espécies de Meloidogyne em cenoura no Brasil

Root-knot nematodes (RKN - Meloidogyne spp.) are one of the most serious threats to carrot production worldwide. In Brazil, carrots are grown throughout the year, and economic losses due to RKN are reported. Since little is known on the distribution of RKN species in carrot fields in Brazil, we collected plant and soil samples from 35 fields across six states. Based on the morphology of perineal patterns, esterase phenotypes and species-specific PCR, three Meloidogyne species were identified: 60% of the fields were infested with Meloidogyne incognita, M. javanica was reported in 42.9% of the areas, whereas M. hapla was detected in 17.1% of carrot fields. Mixed populations were reported in 20% of the areas with a predominance of M. incognita + M. javanica. The combination of morphological, biochemical, and molecular techniques is a useful approach to identify RKN species.(AU)

Os nematoides-das-galhas (RKN - Meloidogyne spp.) são uma das mais sérias ameaças à produção de cenoura no mundo. No Brasil, as cenouras são cultivadas ao longo do ano, e as perdas econômicas devido à RKN são frequentemente relatadas. Como pouco se sabe sobre a distribuição de espécies RKN em campos de cenoura no Brasil, coletamos amostras de plantas e solo de 35 campos em seis estados. Baseado na morfologia do padrão perineal, fenótipos de esterase e/ou PCR espécie-específica, três espécies de Meloidogyne foram identificadas: 60% dos campos estavam infestados por Meloidogyne incognita, M. javanica foi encontrada em 42,9% das áreas, enquanto M. hapla foi detectada em 17,1% dos campos de cenoura. Populações mistas foram encontradas em 20% das áreas, com predominância de M. incognita + M. javanica. A combinação de técnicas morfológicas, bioquímicas e moleculares é uma abordagem útil para identificar espécies de RKN.(AU)

Sustainability of carrot-cowpea intercropping systems through optimization of green manuring and spatial arrangements / Sustentabilidade de sistemas consorciados de cenoura e feijão-caupi por meio da otimização da adubação verde e arranjos espaciais

ABSTRACT: One of the biggest challenges in intercropping of two or more crops is to maintain their productivity as that of their sole counterparts. In order to obtain sustainable intercropping systems in a semi-arid environment, this study evaluated the agro-economic advantage and sustainability of intercropped systems of carrot and cowpea, optimizing the green manuring and spatial arrangements. Experiments were conducted in the period from July to October 2017 and 2018, using a randomized complete block design with the treatments arranged in a 4 x 3 factorial scheme, with four replications. Treatments included four amounts of M. aegyptia incorporated into the soil (20, 35, 50, and 65 t ha-1 on dry basis) with three spatial arrangements (2:2, 3:3, and 4:4) between the components cultures formed from cowpea rows alternated with carrot rows. The agro-economic advantage indices evaluated in the intercropping systems were: land equivalent ratio (LER), area-time equivalent ratio (ATER), score of the canonical variable (Z), actual yield loss (AYL), intercropping advantage (IA), gross income (GI), net income (NI), rate of return (RR), and profit margin (PM). The highest agro-economic advantages of the carrot and cowpea intercropping were obtained for LER, ATER, NI, and RR of 2.60, 4.16, US$ 8,720.99 ha-1, and US$ 2.21, respectively, for M. aegyptia biomass amounts of 46.42, 47.82, 32.60 and 31.51t ha-1 added to the soil. The 2: 2 spatial arrangement was the one with the best productive performance, with higher net income and rate of return in the intercropping of carrot-cowpea.

RESUMO: Um dos maiores desafios no consórcio de duas ou mais culturas é manter sua produtividade como a de suas únicas contrapartes. Com o objetivo de obter sistemas de consórcio sustentáveis ​​em ambiente semiárido, este estudo avaliou vantagem agroeconômica e a sustentabilidade de sistemas consorciados de cenoura e feijão-caupi, otimizando a adubação verde e os arranjos espaciais. Experimentos foram conduzidos no período de julho a outubro de 2017 e 2018, em delineamento de blocos ao acaso, com os tratamentos dispostos em esquema fatorial 4 x 3, com quatro repetições. Os tratamentos incluíram quatro quantidades de M. aegyptia incorporadas ao solo (20, 35, 50 e 65 t ha-1 em base seca) com três arranjos espaciais (2: 2, 3: 3 e 4: 4) entre as culturas componentes formadas a partir de fileiras de feijão-caupi alternadas com fileiras de cenoura. Os índices de vantagem agroeconômica avaliados nos sistemas de consorciação foram: índice de uso eficiente da terra (UET), razão de área equivalente no tempo (RAET), escore da variável canônica (Z), perda de rendimento real (PRR), vantagem do consórcio (VC), renda bruta (RB), renda líquida (RL), taxa de retorno (TR) e margem de lucro (ML). As maiores vantagens agroeconômicas do consórcio de cenoura e feijão-caupi foram obtidas para UET, RAET, RL e TR de 2,60, 4,16, US$ 8.720,99 ha-1 e US$ 2,21, respectivamente, para as quantidades de biomassa de M. aegyptia de 46,42, 47,82, 32,60 e 31,51 t ha-1, adicionadas ao solo. O arranjo espacial 2: 2 foi o de melhor desempenho produtivo, com maior receita líquida e taxa de retorno no consórcio entre feijão-caupi e cenoura.

Distribution of Meloidogyne species in carrot in Brazil / Distribuição de espécies de Meloidogyne em cenoura no Brasil

ABSTRACT: Root-knot nematodes (RKN - Meloidogyne spp.) are one of the most serious threats to carrot production worldwide. In Brazil, carrots are grown throughout the year, and economic losses due to RKN are reported. Since little is known on the distribution of RKN species in carrot fields in Brazil, we collected plant and soil samples from 35 fields across six states. Based on the morphology of perineal patterns, esterase phenotypes and species-specific PCR, three Meloidogyne species were identified: 60% of the fields were infested with Meloidogyne incognita, M. javanica was reported in 42.9% of the areas, whereas M. hapla was detected in 17.1% of carrot fields. Mixed populations were reported in 20% of the areas with a predominance of M. incognita + M. javanica. The combination of morphological, biochemical, and molecular techniques is a useful approach to identify RKN species.

RESUMO: Os nematoides-das-galhas (RKN - Meloidogyne spp.) são uma das mais sérias ameaças à produção de cenoura no mundo. No Brasil, as cenouras são cultivadas ao longo do ano, e as perdas econômicas devido à RKN são frequentemente relatadas. Como pouco se sabe sobre a distribuição de espécies RKN em campos de cenoura no Brasil, coletamos amostras de plantas e solo de 35 campos em seis estados. Baseado na morfologia do padrão perineal, fenótipos de esterase e/ou PCR espécie-específica, três espécies de Meloidogyne foram identificadas: 60% dos campos estavam infestados por Meloidogyne incognita, M. javanica foi encontrada em 42,9% das áreas, enquanto M. hapla foi detectada em 17,1% dos campos de cenoura. Populações mistas foram encontradas em 20% das áreas, com predominância de M. incognita + M. javanica. A combinação de técnicas morfológicas, bioquímicas e moleculares é uma abordagem útil para identificar espécies de RKN.

Genetic parameters estimate for plant characters of a particular carrot population in two different agroecologic cultivation systems / Parâmetros genéticos estimados para caracteres de planta de uma população particular de cenoura em dois sistemas de cultivo agroecológico diferentes

Carrots are among the most planted vegetables in Brazil, which represents importance in the national market. This crop can be grown in conventional and agroecological systems, and studies to improve productivity, disease resistance and root quality in agroecological cropping systems are important. The aim of the present work was to estimate genetic parameters that provide a breeding strategy in the search for the development of new varieties of carrot adapted to the conditions of Distrito Federal's agroecology cultivation. Considering data from tests performed in areas of agroecology cultivation (Natural Agriculture-NA and Organic Agriculture-OA), the following characteristics were evaluated: incidence of leaf blight-LB, incidence of root cracking-CRACK, root length-COMP, format of root tip-TP, format of root shoulder-TO, measure of the color of the a* xylem parameter-a*X, measure of the color of the a* phloem parameter-a*F. Traits were evaluated in 100 half-sib progenies derived from Brasília cultivar, using a completely randomized block design. For the characters COMP, a*X, a*F, TP and TO, the treatment X environment interaction was significant according to the results from test F. The values of the individual variance analyses presented significant effect for the following characteristics: COMP, a*X, TP, TO, LB for NA system, and COMP, a*X, a*F, TP for OA system. In NA system, the values of heritability estimates-ha² for the plant characters fluctuated from 65.66 to 25.52% and, in the OA system, the ha² of the characters a*X, was 81.13%. Estimates of genetic gain per cycle for the characters a*X and a*F were lower in NA system than the estimates observed in OA system.

A cenoura está entre as hortaliças mais plantadas no Brasil, o que representa importância no mercado nacional. Essa cultura pode ser cultivada em sistemas convencionais e agroecológicos, sendo importante o desenvolvimento de estudos para melhorar características de produtividade, resistência a doenças e qualidade de raiz em sistemas com base agroecológica de cultivo. O objetivo do presente trabalho foi estimar parâmetros genéticos que fornecem uma estratégia de melhoramento na busca pelo desenvolvimento de novas variedades de cenoura adaptadas às condições do cultivo agroecológico do Distrito Federal. Considerando dados de testes realizados em áreas de cultivo agroecológico (Agricultura Natural - NA e Agricultura Orgânica - OA), foram avaliadas as seguintes características: incidência de queima das folhas - LB, incidência de rachadura radicular - RACH, comprimento de raiz - COMP, formato de raiz -TP, formato do ombro -TO, medida da cor do parâmetro a * do xilema ­ a*X, medida da cor do parâmetro a *do floema ­ a*F. As características foram avaliadas em 100 progênies de meios-irmãos derivadas da cultivar Brasília, usando um delineamento de blocos inteiramente casualizados. Para os caracteres COMP, a*X, a*F, TP e TO, a interação tratamento X ambiente foi significativa de acordo com os resultados do teste F. Os valores das análises de variância individuais apresentaram efeito significativo para as seguintes características: COMP, a*X, TP, TO, LB para o sistema NA e COMP, a*X, um a*F, TP para o sistema OA. No sistema NA, os valores de estimativa de herdabilidade - ha² para os caracteres da planta variaram de 65,66 a 25,52% e, no sistema OA, o ha² da característica a*X foi de 81,13%. As estimativas de ganho genético por ciclo para os caracteres a*X e a*F foram menores no sistema NA do que as estimativas observadas no sistema OA.

Identification and Quantification of a Phytotoxic Metabolite from Alternaria dauci.

Alternaria dauci is the causal agent of Alternaria leaf blight (ALB) in carrot (Daucus carota) crops around the world. However, to date, A. dauci has received limited attention in its production of phytotoxic metabolites. In this investigation, the bioassay-guided isolation of the extract from liquid cultures of A. dauci resulted in the isolation of two metabolites identified as α-acetylorcinol (1) and p-hydroxybenzoic acid (2), based on their spectroscopic data and results from chemical correlation reactions. Testing of both metabolites in different assays showed an important phytotoxic activity for p-hydroxybenzoic acid (2) when tested in the leaf-spot assay on parsley (Petroselinum crispum), in the leaf infiltration assay on tobacco (Nicotiana alata) and marigold (Tagetes erecta), and in the immersion assay on parsley and parsnip (Pastinaca sativa) leaves. Quantification of the two metabolites in the crude extract of A. dauci kept at different times showed that p-hydroxybenzoic acid (2) is one of the first metabolites to be synthesized by the pathogen, suggesting that this salicylic acid derivative could play an important role in the pathogenicity of the fungus.