Tropical peanut maturation scale for harvesting seeds with superior quality.

Determining the moment for harvesting the tropical peanut with a focus on superior seed quality is not an easy task. Particularities such as indeterminate flowering, underground fruiting and uneven maturation further increase this technical challenge. It is in this context that we aim to investigate harvest indicators based on the maturation and late maturation phases of tropical peanuts to obtain seeds with superior physiological and health quality. The plants were grown in field conditions and their development stages were carefully monitored until seed production. The water content, dry weight, germination capacity, desiccation tolerance, vigor, longevity, and seed pathogens were evaluated throughout these stages. We showed that seeds from early stages (R5 and R6) did not fully tolerate desiccation and were highly sensitive to pathogen contamination after storage (Aspergillus, Penicillium, and Bacteria). At late stages (R7, R8, and R9), the seeds had optimized vigor, longevity and bioprotection against fungi and thermal stress. The peanut maturation scale for tropical agriculture provides unique harvesting guidelines that make it possible to monitor the plants' development stages with a focus on producing superior quality seeds.

Experimental Comparison between Ethanol and Hexane as Solvents for Oil Extraction from Peanut Press Cake.

Ethanol (Et) has been suggested as a substitute for hexane (Hx) for use in the extraction of oils from different oleaginous matrices. In this study, Et and Hx were used to extract the residual oil present in a peanut press cake (PPC). Certain variables, such as temperature, solid/solvent ratio and the number of contact stages, in the sequential cross-current extraction process were evaluated; additionally, the effects of these variables on oils (POEt and POHx) and defatted solids (DSEt and DSHx) were explored. Hx exhibited an extraction yield of 86 ± 2% in two stages at 55 °C and a solid/solvent mass ratio of 1/4. Compared with Hx extraction, to achieve an Et extraction yield of 87 ± 4%, it was necessary to use a higher temperature (75 °C), a greater amount of solvent (solid/solvent ratio of 1/5) and a greater number of contact stages (3). POEt and POHx presented compositions in terms of fatty acids and triacylglycerols and physical properties similar to that of cold-pressed peanut oil (CPPO). POEt showed a more intense green/yellow hue and higher free acidity (1.47 ± 0.03%) than POHx and CPPO (0.82 ± 0.04 and 0.43 ± 0.02 free acidity mass %, respectively), indicating that the deacidification and bleaching steps in refining should be encumbered. DSEt and DSHx exhibited high protein contents (>45% by mass) and nitrogen solubilities (86 ± 6 and 98 ± 1%, respectively), indicating that they could be used to obtain proteins.

Fungal identification in peanuts seeds through multispectral images: Technological advances to enhance sanitary quality.

The sanitary quality of seed is essential in agriculture. This is because pathogenic fungi compromise seed physiological quality and prevent the formation of plants in the field, which causes losses to farmers. Multispectral images technologies coupled with machine learning algorithms can optimize the identification of healthy peanut seeds, greatly improving the sanitary quality. The objective was to verify whether multispectral images technologies and artificial intelligence tools are effective for discriminating pathogenic fungi in tropical peanut seeds. For this purpose, dry peanut seeds infected by fungi (A. flavus, A. niger, Penicillium sp., and Rhizopus sp.) were used to acquire images at different wavelengths (365 to 970 nm). Multispectral markers of peanut seed health quality were found. The incubation period of 216 h was the one that most contributed to discriminating healthy seeds from those containing fungi through multispectral images. Texture (Percent Run), color (CIELab L*) and reflectance (490 nm) were highly effective in discriminating the sanitary quality of peanut seeds. Machine learning algorithms (LDA, MLP, RF, and SVM) demonstrated high accuracy in autonomous detection of seed health status (90 to 100%). Thus, multispectral images coupled with machine learning algorithms are effective for screening peanut seeds with superior sanitary quality.

Population dynamics, vertical distribution and damage characterization of burrower bug in peanut

Although the burrower bug (Cyrtomenus mirabilis) is considered a vitalsoil pest in peanut crops, Arachis hypogaea L., in South America, there is little information on its occurrence and damage characterization. This study aimed to evaluate the vertical distribution and fluctuation of the burrower bug in the soil and the damage this species causes in peanuts. Two peanut cultivars (IAC OL3 and IAC 503) were evaluated in three locations in the state of São Paulo: Pindorama, Ribeirão Preto and Votuporanga, in the 2017/18 and 2018/19 harvests. Trenches were dug 0.5 m long, 0.3 m wide and 0.3 m deep, along plant lines at four spots on each sampling date, and stratified in layers 10 cm deep. Plant samples (0.5 m) were collected and evaluated for number of pods and percentage of kernels with symptoms of insect damage. More than 85 % of the C. mirabilis population was found in depths of up to 10 cm, especially after plant fructification, and an increase in nymphs from 100 days after sowing (DAS) was seen when an increased number of maturing pods was observed. The occurrence of nymphs and adults of C. mirabilis and their damage to peanut kernels was similar in both cultivars (IAC OL3 and IAC 503), when these were harvested according to their developmental cycles.

An Approach Using Emerging Optical Technologies and Artificial Intelligence Brings New Markers to Evaluate Peanut Seed Quality.

Seeds of high physiological quality are defined by their superior germination capacity and uniform seedling establishment. Here, it was investigated whether multispectral images combined with machine learning models can efficiently categorize the quality of peanut seedlots. The seed quality from seven lots was assessed traditionally (seed weight, water content, germination, and vigor) and by multispectral images (area, length, width, brightness, chlorophyll fluorescence, anthocyanin, and reflectance: 365 to 970 nm). Seedlings from the seeds of each lot were evaluated for their photosynthetic capacity (fluorescence and chlorophyll index, F0, Fm, and Fv/Fm) and stress indices (anthocyanin and NDVI). Artificial intelligence features (QDA method) applied to the data extracted from the seed images categorized lots with high and low quality. Higher levels of anthocyanin were found in the leaves of seedlings from low quality seeds. Therefore, this information is promising since the initial behavior of the seedlings reflected the quality of the seeds. The existence of new markers that effectively screen peanut seed quality was confirmed. The combination of physical properties (area, length, width, and coat brightness), pigments (chlorophyll fluorescence and anthocyanin), and light reflectance (660, 690, and 780 nm), is highly efficient to identify peanut seedlots with superior quality (98% accuracy).

Physiological potential and health of peanut seed treated with ozone / Potencial fisiológico e sanidade de sementes de amendoim submetidas a ozonização

Peanut seed can be infected by pathogen diseases that adversely affect the oil crop's value chain. Ozone gas (O3) can be an alternative for the control of fungal diseases due to its high oxidizing potential. In this study, we investigated the effects of O3 exposure time on physiological and health characteristics of seed from three peanut cultivars. Seed from peanut cultivars Granoleico, IAC OL3, and IAC 503 were analyzed for their health (blotter test) and physiological potential (germination, first count, and seedling length) after exposure to O3 for 0, 1, 8, and 16 h. Peanut seed physiological quality and health differed among cultivars. Exposure of seed from peanut cultivars IAC OL3, IAC 503, and Granoleico to O3 at a rate of 600 mg h-1 did not affect the development of normal seedlings as measured by the first count and germination, but seedling length increased, decreased, or was not affected in cultivars Granoleico, IAC 503, and IAC OL3, respectively. Also, O3 did not eradicate fungal infections in peanut seed treated with O3 at a rate of 600 mg h-1 for up to 16 h, but the incidence of the fungus Rhizopus sp. in seed from cultivars IAC OL3, Granoleico, and IAC 503 increased, decreased or was not affected, respectively, after 8 h.(AU)

Sementes de amendoim são alvos de patógenos e geram problemas à cadeia produtiva da espécie oleaginosa. Uma alternativa de controle de microrganismos é a aplicação da ozonização devido seu alto potencial de oxidação. Portanto, o objetivo deste ensaio foi avaliar a aplicação do gás ozônio, em três cultivares de amendoim, nos atributos fisiológicos e sanitários de acordo com diferentes períodos de exposição das sementes ao O3. Neste ensaio, sementes de amendoim dos cultivares Granoloeico, IAC OL3 e IAC 503 foram analisadas quanto a sanidade (blotter test) e potencial fisiológico (germinação, primeira contagem e comprimento de plântulas) após submissão ao gás ozônio por 0, 1, 8 e 16 horas. De acordo com os cultivares, sementes de amendoim apresentam diferentes desempenhos fisiológicos e sanitários de qualidade. A exposição de sementes dos cultivares de amendoim IAC OL3, IAC 503 e Granoleico ao gás ozônio até 16 horas na taxa de 600 mg/h não interfere na formação de plântulas normais avaliada na primeira contagem de germinação e na germinação, entretanto há efeitos de incremento, decréscimo ou nulo no comprimento de plântulas para os cultivares Granoleico, IAC 503 e IAC OL3, respectivamente. Não há erradicação de fungos presentes em sementes de amendoim expostas ao gás ozônio numa taxa de 600mg/h até 16 horas, porém a incidência do fungo Rhizopus sp. aumenta, diminui ou é indiferente no período de 8h para os cultivares IAC OL3, Granoleico e IAC 503, respectivamente.(AU)

Dynamics of Macronutrient Uptake and Removal by Modern Peanut Cultivars.

The productive potential of new peanut cultivars has increased over the years in relation to old cultivars, especially when compared with ones with upright growth habit. Thus, the requirement for macronutrients for these new cultivars may also have increased, making the existing fertilizer recommendation tables obsolete, thus increasing the need for further studies measuring the real macronutrient requirements of these new peanut cultivars. Our study aimed to evaluate the growth patterns and the macronutrient absorption rate throughout the biological cycle of three modern runner peanut cultivars, as well as the potential for producing dry matter, pods, and kernels, and their respective macronutrient accumulations. The experimental design was a randomized complete block with split-plots and nine replications. The experimental plots consisted of three peanut cultivars (IAC Runner 886, IAC 505, and IAC OL3), and subplots consisted of nine plant samplings (14, 28, 42, 56, 70, 84, 105, 126, and 147 days after emergence (DAE)). Our results showed that modern peanut cultivars presented nutrient accumulation around 30 to 40 days earlier than older cultivars, as well as increasing the uptake by K and Ca. IAC 505 absorbed higher amounts of macronutrients and resulted in greater dry matter production compared with IAC OL3 and IAC Runner 886. Our study demonstrated that the most appropriate time for plants to find greater availability of nutrients in the soil is 70 to 84 DAE, in addition to highlighting the need for updates on nutritional recommendations for higher yields of modern peanut cultivars.

Role of ethylene in effective establishment of the peanut-bradyrhizobia symbiotic interaction.

Ethylene has been implicated in nitrogen fixing symbioses in legumes, where rhizobial invasion occurs via infection threads (IT). In the symbiosis between peanut (Arachis hypogaea L.) and bradyrhizobia, the bacteria penetrate the root cortex intercellularly and IT are not formed. Little attention has been paid to the function of ethylene in the establishment of this symbiosis. The aim of this article is to evaluate whether ethylene plays a role in the development of this symbiotic interaction and the participation of Nod Factors (NF) in the regulation of ethylene signalling. Manipulation of ethylene in peanut was accomplished by application of 1-aminocyclopropane-1-carboxylic acid (ACC), which mimics applied ethylene, or AgNO3, which blocks ethylene responses. To elucidate the participation of NF in the regulation of ethylene signalling, we inoculated plants with a mutant isogenic rhizobial strain unable to produce NF and evaluated the effect of AgNO3 on gene expression of NF and ethylene responsive signalling pathways. Data revealed that ethylene perception is required for the formation of nitrogen-fixing nodules, while addition of ACC does not affect peanut symbiotic performance. This phenotypic evidence is in agreement with transcriptomic data from genes involved in symbiotic and ethylene signalling pathways. NF seem to modulate the expression of ethylene signalling genes. Unlike legumes infected through IT formation, ACC addition to peanut does not adversely affect nodulation, but ethylene perception is required for establishment of this symbiosis. Evidence for the contribution of NF to the modulation of ethylene-inducible defence gene expression is provided.

Evaluation of cellular safety and the chemical composition of the peanut (Arachis hypogaea L.) ethanolic extracts.

Arachis hypogaea L. (Leguminosae) is distributed in tropical and subtropical areas. Peanut has high nutritional and commercial value. Scientific research showed that peanut has biological properties such as anticancer, antioxidant, antiinflammatory. However, it is necessary to know if consumption of peanut, either as food or as a phytopharmaceutical implies a health risk. The aim was to evaluate cytotoxicity and genotoxicity of ethanolic extracts from A. hypogaea. Also, chemical characterization of these extracts was performed. Cytotoxicity was evaluated by MTT and Neutral Red Uptake (NRU) assays on Vero cells. Genotoxicity was studied by Micronuclei and comet assays on Balb/C mice. Qualitative and quantitative chemical analysis of extracts were performed. Results showed that extracts have low cytotoxicity. Tegument ethanolic extract (TEE) and Seed ethanolic extract (SEE) were not genotoxic. The treatments with TEE at 250 mg/kg and SEE at 2000 mg/kg revealed (highest concentrations evaluated) some toxicity on blood marrow cells of mice. Chemical characterization indicated that TEE had 74.33 ± 1.10 mg GAE/g of dried extract and SEE had 15.05 ± 0.06 mg GAE/g of dried extract of total phenolic content. Also, proanthocyanidins (O.D. at 550 nm 1.39 ± 0.15) and caffeic acid (2.46%) were identified in TEE. While, linoleic acid (58.84%) oleic acid (11.31%) and palmitic acid (8.37%) were major compounds of SEE. In conclusion, peanut consumption is safe at concentrations recommended for healthy uses, such as nutrition, and phytomedicine.

Desenvolvimento de amendoim submetido a adubação fosfatada e potássica e diferentes espaçamento entre plantas / Development of peanuts subjected to phosphate and potassium fertilization and different plant spacing

Objetivou-se avaliar o cultivo de amendoim em função da adubação fosfatada e potássica na semeadura e do espaçamento entre plantas, em regime de sequeiro e irrigação por gotejamento no Cariri-CE. Foi utilizado o delineamento experimental em bloco ao acaso, em esquema de parcela subdividida com quatro repetições. As parcelas foram constituídas pelas doses de adubação com K e P de semeadura (0, 50, 100 e 150% da dose recomendada) e as subparcelas por dois espaçamentos entre plantas (10 e 20 cm). As variáveis avaliadas foram população inicial, população final, altura da planta, massa de grãos por planta, número de vagens por planta, massa de vagens por planta, massa de grãos por vagens, massa de1000 grãos e massa de 100 vagens, produtividade de vagens, produtividade de grãos e porcentagem de grãos não comerciais. Os resultados demonstraram que o sistema sequeiro e irrigação influenciaram na produção do amendoim e a adubação no número vagens e a massa de vagens por planta foram significativas obtendo o ponto de máxima nas doses de 82,58 e 80,37%, respectivamente. O espaçamento de 20 cm ampliou a produtividade de grãos por plantas e a massa de 1000 grãos em 10,77% e 14,8% respectivamente.

The objective of this study was to evaluate the cultivation of peanuts as a function of phosphate and potassium fertilization in sowing and spacing between plants, in dry land and drip irrigation in Cariri-CE. A randomized block design was used in a split-plot scheme with four replications. The plots consisted of the fertilization doses with K and P of sowing (0,50, 100 and 150% of the recommended dose) and the subplots by two spacings between plants (10 and 20cm). The variables evaluated were initial population, final population, plant height, grain mass per plant, number of pods per plant, pod mass per plant, grain mass per pods, mass of 1000 grains and mass of 100 pods, pod yield, grain yield and percentage of non-commercial grains. The results showed that the dry sequeiro and irrigation system influenced the production of peanuts and fertilization in the number of pods and the mass of pods per plant were significant, obtaining the maximum point at doses of 82.58 and 80.37%, respectively. The spacing of 20 cm increased grain yield by plants and the mass of 1000 grains by 10.77% and 14.8%, respectively.

Desenvolvimento de amendoim submetido a adubação fosfatada e potássica e diferentes espaçamento entre plantas / Development of peanuts subjected to phosphate and potassium fertilization and different plant spacing

Objetivou-se avaliar o cultivo de amendoim em função da adubação fosfatada e potássica na semeadura e do espaçamento entre plantas, em regime de sequeiro e irrigação por gotejamento no Cariri-CE. Foi utilizado o delineamento experimental em bloco ao acaso, em esquema de parcela subdividida com quatro repetições. As parcelas foram constituídas pelas doses de adubação com K e P de semeadura (0, 50, 100 e 150% da dose recomendada) e as subparcelas por dois espaçamentos entre plantas (10 e 20 cm). As variáveis avaliadas foram população inicial, população final, altura da planta, massa de grãos por planta, número de vagens por planta, massa de vagens por planta, massa de grãos por vagens, massa de1000 grãos e massa de 100 vagens, produtividade de vagens, produtividade de grãos e porcentagem de grãos não comerciais. Os resultados demonstraram que o sistema sequeiro e irrigação influenciaram na produção do amendoim e a adubação no número vagens e a massa de vagens por planta foram significativas obtendo o ponto de máxima nas doses de 82,58 e 80,37%, respectivamente. O espaçamento de 20 cm ampliou a produtividade de grãos por plantas e a massa de 1000 grãos em 10,77% e 14,8% respectivamente.(AU)

The objective of this study was to evaluate the cultivation of peanuts as a function of phosphate and potassium fertilization in sowing and spacing between plants, in dry land and drip irrigation in Cariri-CE. A randomized block design was used in a split-plot scheme with four replications. The plots consisted of the fertilization doses with K and P of sowing (0,50, 100 and 150% of the recommended dose) and the subplots by two spacings between plants (10 and 20cm). The variables evaluated were initial population, final population, plant height, grain mass per plant, number of pods per plant, pod mass per plant, grain mass per pods, mass of 1000 grains and mass of 100 pods, pod yield, grain yield and percentage of non-commercial grains. The results showed that the dry sequeiro and irrigation system influenced the production of peanuts and fertilization in the number of pods and the mass of pods per plant were significant, obtaining the maximum point at doses of 82.58 and 80.37%, respectively. The spacing of 20 cm increased grain yield by plants and the mass of 1000 grains by 10.77% and 14.8%, respectively.(AU)

Genome-wide development of polymorphic microsatellite markers and their application in peanut breeding program

BACKGROUND: Cultivated peanut (Arachis hypogaea. L) represents one of the most important oil crops in the world. Although much effort has been expended to characterize microsatellites or Simple Sequence Repeats (SSRs) in peanut, the quantity and quality of the markers in breeding applications remain limited. Here, genome-wide SSR characterization and marker development were performed using the recently assembled genome of the cultivar Tifrunner. RESULTS: In total, 512,900 microsatellites were identified from 2556.9-Mb genomic sequences. Based on the flanking sequences of the identified microsatellites, 7757 primer pairs (markers) were designed, and further evaluated in the assembled genomic sequences of the tetraploid Arachis cultivars, Tifrunner and Shitouqi, and the diploid ancestral species, A. duranensis and A. ipaensis. In silico PCR analysis showed that the SSR markers had high amplification efficiency and polymorphism in four Arachis genotypes. Notably, nearly 60% of these markers were single-locus SSRs in tetraploid Arachis species, indicating they are more specific in distinguishing the alleles of the A and B sub-genomes of peanut. In addition, two markers closely related with purple testa color and 27 markers near to FAD2 genes were identified, which could be used for breeding varieties with purple testa and high-oleic acid content, respectively. Moreover, the potential application of these SSR markers in tracking introgressions from Arachis wild relatives was discussed. CONCLUSIONS: This study reported the development of genomic SSRs from assembled genomic sequences of the tetraploid Arachis Tifrunner, which will be useful for diversity analysis, genetic mapping and functional genomics studies in peanut

Polyphenol analysis using high-resolution mass spectrometry allows differentiation of drought tolerant peanut genotypes.

BACKGROUND: Peanut (Arachis hypogaea L.) is an important economic food crop highly appreciated worldwide. Although peanut cultivation has been expanding to dry regions, with water stress during growth stages, current genotypes are not adapted to drought. This study aimed to identify and quantify the full range of polyphenols in five peanut genotypes with different degrees of drought tolerance developed by Embrapa (Brazil) using ultra-high-definition accurate-mass liquid chromatography-electrospray ionization-LTQ-Orbitrap-mass spectrometry. RESULTS: Fifty-eight polyphenols of the classes hydroxybenzoic acids, hydroxycinnamic acids, flavanols, flavonols and flavanones were identified and quantified using high mass accuracy data and confirmed by tandem mass spectrometric experiments. High-definition mass spectrometric analyses revealed nine phenolic compounds that have never been reported in peanuts before. Polyphenol assessment using multivariate analysis allowed identification of the level of similarities among the five peanut genotypes studied. CONCLUSION: Higher drought-tolerant genotypes exhibited higher content of flavonoids, which suggests a relationship between these compounds and drought tolerance traits. © 2019 Society of Chemical Industry.

Bradyrhizobium sp. enhance ureide metabolism increasing peanuts yield.

This study aimed to evaluate the effects of seed inoculation with Bradyrhizobium sp. and co-inoculation with Azospirillum brasilense. The seed treatments were as follows: control (without inoculation); A. brasilense (2 mL per kg-1 of seed); A. brasilense (4 mL per kg-1 of seed); Bradyrhizobium sp. (2 mL per kg-1 of seed); Bradyrhizobium sp. (4 mL per kg-1 of seed); A. brasilense + Bradyrhizobium sp. (2 mL of each strain per kg-1 of seed); and A. brasilense + Bradyrhizobium sp. (4 mL of each strain per kg-1 of seed). Peanut plants from seeds inoculated with Bradyrhizobium sp. and A. brasilense exhibited highest leaf concentration of photosynthetic pigments, carotenoids, nitrate, ammonia and amino acids. The inoculation of seeds with Bradyrhizobium sp. resulted in plants with increased concentrations of total soluble sugars, and ureides compared to the untreated plants. In contrast, seeds treated with A. brasilense alone resulted in plants exhibiting highest concentration of amino acids, which represent the highest concentration of nitrogen compounds in peanut plants. Seed inoculation with Bradyrhizobium sp. at a rate of 2 mL kg-1 was identified as the best treatment to promote increased biological nitrogen fixation and generate higher peanut yields.

Methods of cultivation and technical coefficients of peanuts in the Bahian Recôncavo / Métodos de cultivo e coeficientes técnicos do amendoim no Recôncavo Baiano

The objective of this study was to collect information about peanut cultivation methods adopted by family farmers in the Bahian Recôncavo (region that surrounds the bay in the state of Bahia, Brazil), using a specific form and also direct information from farmers. An ethnobotanical survey was carried out in the mesoregion of the Bahian Recôncavo in the following municipalities: Conceição do Almeida, Cruz das Almas, Maragogipe, São Felipe, São Felix, Sapeaçú and Laje (Vale do Jequiriçá), where 60 local farmers answered a nonstructured questionnaire about peanut cultivation. The cultivation system was estimated based on technical coefficients related to peanut cultivation in the area evaluated. The peanut cultivation system is carried out by family farmers from the Bahian Recôncavo who employ outdated practices and do not use the required basic steps. The technical coefficients analyzed show that the cultivation of peanut is an unprofitable activity when considering the high cost of production in this region, even though productivity is higher than in the entire state as well as in the Northeast region. Farmers in the Bahian Recôncavo do not consider the actual production costs of peanuts since they use seeds from previous crops and do not account for the labor costs of family members. There is a lack of active and continuous technical assistance to family farmers, not only in relation to the cultivation system, but also the possibility of other destinations for peanuts produced in the region.(AU)

O objetivo deste estudo foi levantar informações sobre os métodos de cultivo da cultura do amendoim, adotados por agricultores familiares do Recôncavo Baiano, utilizando-se de um formulário específico e de informações diretas dos agricultores. Foi realizado um levantamento etnobotânico nos municípios da mesorregião do Recôncavo Baiano: Conceição do Almeida, Cruz das Almas, Maragogipe, São Felipe, São Félix, Sapeaçú e no município de Laje (Vale do Jequiriçá), onde 60 agricultores foram entrevistados, por meio de um questionário não estruturado, referente ao cultivo do amendoinzeiro no Recôncavo Baiano. A estimativa do sistema de cultivo foi realizada com base em coeficientes técnicos referentes ao cultivo do amendoinzeiro na área de estudo. O sistema de cultivo do amendoim é realizado por agricultores familiares do Recôncavo Baiano utilizando práticas ultrapassadas, destituídas das etapas básicas necessárias. Os coeficientes técnicos analisados demonstram que o cultivo do amendoinzeiro é uma atividade pouco lucrativa ao se levar em consideração o alto custo de produção nessa região, mesmo a produtividade sendo maior quando comparada com a do estado, assim como com a da região Nordeste. Os agricultores do Recôncavo Baiano não consideram os custos de produção real do amendoim, uma vez que utilizam sementes de cultivos anteriores e não contabilizam os custos de mão de obra dos familiares. Falta aos agricultores familiares assistência técnica atuante e continuada, não só com relação ao sistema de cultivo como também com a possibilidade de outras destinações para o amendoim produzido na região.(AU)

Methods of cultivation and technical coefficients of peanuts in the Bahian Recôncavo / Métodos de cultivo e coeficientes técnicos do amendoim no Recôncavo Baiano

The objective of this study was to collect information about peanut cultivation methods adopted by family farmers in the Bahian Recôncavo (region that surrounds the bay in the state of Bahia, Brazil), using a specific form and also direct information from farmers. An ethnobotanical survey was carried out in the mesoregion of the Bahian Recôncavo in the following municipalities: Conceição do Almeida, Cruz das Almas, Maragogipe, São Felipe, São Felix, Sapeaçú and Laje (Vale do Jequiriçá), where 60 local farmers answered a nonstructured questionnaire about peanut cultivation. The cultivation system was estimated based on technical coefficients related to peanut cultivation in the area evaluated. The peanut cultivation system is carried out by family farmers from the Bahian Recôncavo who employ outdated practices and do not use the required basic steps. The technical coefficients analyzed show that the cultivation of peanut is an unprofitable activity when considering the high cost of production in this region, even though productivity is higher than in the entire state as well as in the Northeast region. Farmers in the Bahian Recôncavo do not consider the actual production costs of peanuts since they use seeds from previous crops and do not account for the labor costs of family members. There is a lack of active and continuous technical assistance to family farmers, not only in relation to the cultivation system, but also the possibility of other destinations for peanuts produced in the region.(AU)

O objetivo deste estudo foi levantar informações sobre os métodos de cultivo da cultura do amendoim, adotados por agricultores familiares do Recôncavo Baiano, utilizando-se de um formulário específico e de informações diretas dos agricultores. Foi realizado um levantamento etnobotânico nos municípios da mesorregião do Recôncavo Baiano: Conceição do Almeida, Cruz das Almas, Maragogipe, São Felipe, São Félix, Sapeaçú e no município de Laje (Vale do Jequiriçá), onde 60 agricultores foram entrevistados, por meio de um questionário não estruturado, referente ao cultivo do amendoinzeiro no Recôncavo Baiano. A estimativa do sistema de cultivo foi realizada com base em coeficientes técnicos referentes ao cultivo do amendoinzeiro na área de estudo. O sistema de cultivo do amendoim é realizado por agricultores familiares do Recôncavo Baiano utilizando práticas ultrapassadas, destituídas das etapas básicas necessárias. Os coeficientes técnicos analisados demonstram que o cultivo do amendoinzeiro é uma atividade pouco lucrativa ao se levar em consideração o alto custo de produção nessa região, mesmo a produtividade sendo maior quando comparada com a do estado, assim como com a da região Nordeste. Os agricultores do Recôncavo Baiano não consideram os custos de produção real do amendoim, uma vez que utilizam sementes de cultivos anteriores e não contabilizam os custos de mão de obra dos familiares. Falta aos agricultores familiares assistência técnica atuante e continuada, não só com relação ao sistema de cultivo como também com a possibilidade de outras destinações para o amendoim produzido na região.(AU)

Physiological response of seeds of peanut genotypes to water deficiency / Resposta fisiológica de sementes de genótipos de amendoim submetidos a deficiência hídrica

Among the factors that may influence the germination process of seeds, water deficiency is considered the most important. The present study aims to evaluate the physiological response of peanut genotypes to water deficiency. The experiment was conducted in a completely randomized design with four replications in a 12 x 7 factorial scheme with 12 peanut genotypes and seven polyethylene glycol 6000 concentrations corresponding to osmotic potentials of 0.00; -0.10; -0.20; -0.40; -0.60; -0.80 and -1.00 MPa. The data were submitted to analysis of variance and Tukey's test at a 5% probability level and, when significant, to analysis of variance adjusted to a quadratic polynomial curve. The germination percentage, seed vigor evaluated by the speed germination index, mean germination time, root length and root dry matter of some genotypes were affected by the osmotic potentials. Among the genotypes, there is a differential response related to the water deficiency level. In relation to the physiological response of the seeds, the lineages 506, 599, and 870 and the cultivar IAC Tatu-ST have a higher tolerance of water deficit. The peanut genotypes begin to suffer the effects of water deficiency at the osmotic potential of -0.4 MPa

Entre os fatores externos que podem influenciar o processo germinativo das sementes, a deficiência hídrica é considerada o mais importante. Dessa forma, o objetivo do presente trabalho foi avaliar a resposta fisiológica de sementes de genótipos de amendoim submetidos à deficiência hídrica. O experimento foi conduzido em esquema fatorial 12 x 7, tendo como tratamentos sementes de 12 genótipos de amendoim submetidos a sete concentrações de polietilenoglicol 6000, nos potenciais osmóticos correspondentes a 0,00; -0,10; -0,20; -0,40; -0,60; -0,80; -1,00 MPa. Constatou-se que os genótipos são afetados pelos potenciais osmóticos e, entre os genótipos, há resposta diferenciada em relação ao nível de deficiência hídrica. Em relação à resposta fisiológica das sementes, as linhagens 506, 599, 870 e a cultivar IAC Tatu-ST possuem maiortolerância à deficiência hídrica. Todos os genótipos de amendoim começam a sofrerem os efeitos da deficiência hídrica a partir do potencial osmótico de -0,4 MPa para a maior parte das características avaliadas

Eficiência do uso da água pela cultura do amendoim sob diferentes lâminas de irrigação e formas de adubação / Efficiency of water use by peanut crop under different irrigation depths and forms of fertilization

Objetivou-se, com este trabalho avaliar a eficiência do uso da água pela cultura do amendoim submetido a diferentes níveis de irrigação e formas de adubação. O experimento foi conduzido em casa de vegetação no período de 20/03/2017 a 18/07/2017, no Campo Experimental do Centro de Ciências Agrárias, localizado no município de Rio Largo, AL. O delineamento experimental foi inteiramente ao acaso, no esquema fatorial 4 x 2, sendo quatro lâminas de irrigação (50, 75, 100, 125% da ETc) e duas formas de adubação (química e orgânica). Foram avaliadas as seguintes variáveis: número de folhas (NF), massa seca da raiz (MSR), massa seca da parte aérea (MSPA), número de grãos (NG), produção de grãos por planta (PGP), peso de grãos de em vagem (PGV) e a eficiência do uso de água (EUA). Constatou-se que a adubação orgânica, promoveu aumento no número de folhas e de grãos e que a máxima eficiência do uso da água pela cultura do amendoim, corresponde a 0,79 g L-1 de água consumida pela cultura, com a lâmina irrigação 62% da ETc, o que indica em elevada eficiência na transformação da água consumida em grãos.

The objective of this work was to evaluate the efficiency of water use by the peanut crop subjected to different irrigation levels and forms of fertilization. The experiment was carried out in a greenhouse in the period from 20/03/2017 to 18/07/2017, in the perimental field of the Agrarian Sciences Center, located in the municipality of Rio Largo, AL. The experimental design was completely randomized in the factorial scheme 4 x 2, four irrigation depths (50, 75, 100, 125% of ETc) and two forms of fertilization (chemical and organic). The following variables were evaluated: number of Leaves (NF), Root dry mass (MSR), shoot dry mass (MSPA), number of grains (NG), grain yield per plant (PGP), POD grain weight (PGV) and water use efficiency (US). It was found that the organic fertilization, promotes an increase in the number of leaves and grains and that the maximum efficiency of water use by the peanut crop, corresponds to 0.79 g L-1 of water consumed by the crop, with the irrigation depth 62% of ETc, which indicates in high efficiency in the transformation of the water consumed in grains.

Eficiência do uso da água pela cultura do amendoim sob diferentes lâminas de irrigação e formas de adubação / Efficiency of water use by peanut crop under different irrigation depths and forms of fertilization

Objetivou-se, com este trabalho avaliar a eficiência do uso da água pela cultura do amendoim submetido a diferentes níveis de irrigação e formas de adubação. O experimento foi conduzido em casa de vegetação no período de 20/03/2017 a 18/07/2017, no Campo Experimental do Centro de Ciências Agrárias, localizado no município de Rio Largo, AL. O delineamento experimental foi inteiramente ao acaso, no esquema fatorial 4 x 2, sendo quatro lâminas de irrigação (50, 75, 100, 125% da ETc) e duas formas de adubação (química e orgânica). Foram avaliadas as seguintes variáveis: número de folhas (NF), massa seca da raiz (MSR), massa seca da parte aérea (MSPA), número de grãos (NG), produção de grãos por planta (PGP), peso de grãos de em vagem (PGV) e a eficiência do uso de água (EUA). Constatou-se que a adubação orgânica, promoveu aumento no número de folhas e de grãos e que a máxima eficiência do uso da água pela cultura do amendoim, corresponde a 0,79 g L-1 de água consumida pela cultura, com a lâmina irrigação 62% da ETc, o que indica em elevada eficiência na transformação da água consumida em grãos.(AU)

The objective of this work was to evaluate the efficiency of water use by the peanut crop subjected to different irrigation levels and forms of fertilization. The experiment was carried out in a greenhouse in the period from 20/03/2017 to 18/07/2017, in the perimental field of the Agrarian Sciences Center, located in the municipality of Rio Largo, AL. The experimental design was completely randomized in the factorial scheme 4 x 2, four irrigation depths (50, 75, 100, 125% of ETc) and two forms of fertilization (chemical and organic). The following variables were evaluated: number of Leaves (NF), Root dry mass (MSR), shoot dry mass (MSPA), number of grains (NG), grain yield per plant (PGP), POD grain weight (PGV) and water use efficiency (US). It was found that the organic fertilization, promotes an increase in the number of leaves and grains and that the maximum efficiency of water use by the peanut crop, corresponds to 0.79 g L-1 of water consumed by the crop, with the irrigation depth 62% of ETc, which indicates in high efficiency in the transformation of the water consumed in grains.(AU)

Transcriptome profiling and digital gene expression analysis of genes associated with salinity resistance in peanut

Background: Soil salinity can significantly reduce crop production, but the molecular mechanism of salinity tolerance in peanut is poorly understood. A mutant (S1) with higher salinity resistance than its mutagenic parent HY22 (S3) was obtained. Transcriptome sequencing and digital gene expression (DGE) analysis were performed with leaves of S1 and S3 before and after plants were irrigated with 250 mM NaCl. Results: A total of 107,725 comprehensive transcripts were assembled into 67,738 unigenes using TIGR Gene Indices clustering tools (TGICL). All unigenes were searched against the euKaryotic Ortholog Groups (KOG), gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, and these unigenes were assigned to 26 functional KOG categories, 56 GO terms, 32 KEGG groups, respectively. In total 112 differentially expressed genes (DEGs) between S1 and S3 after salinity stress were screened, among them, 86 were responsive to salinity stress in S1 and/or S3. These 86 DEGs included genes that encoded the following kinds of proteins that are known to be involved in resistance to salinity stress: late embryogenesis abundant proteins (LEAs), major intrinsic proteins (MIPs) or aquaporins, metallothioneins (MTs), lipid transfer protein (LTP), calcineurin B-like protein-interacting protein kinases (CIPKs), 9-cis-epoxycarotenoid dioxygenase (NCED) and oleosins, etc. Of these 86 DEGs, 18 could not be matched with known proteins. Conclusion: The results from this study will be useful for further research on the mechanism of salinity resistance and will provide a useful gene resource for the variety breeding of salinity resistance in peanut.