Vessel element morphology of Allagoptera campestris (Mart.) Kuntze (Arecaceae) belowground organs affected by growing conditions.

Allagoptera campestris is an acaulescent, rhizomatous palm tree that occurs in grassland and savanna areas (Cerrado). In the Santa Bárbara Ecological Station (Águas de Santa Bárbara, São Paulo, Brazil) the species is found growing in three distinct conditions: 1) in the understory of Pinus species plantations introduced in the 1970s in formerly open savanna, 2) in an area where Pinus species cultivated in the 1970s were later removed and the remaining material burned, and 3) in an open, undisturbed savanna area without the interference of pines. Anatomical studies carried out with A. campestris leaves collected in the same three areas indicated leaf plasticity in response to growth conditions. To verify whether there are differences in vessel element morphology in belowground organs, light, and scanning electron microscopy analyses were conducted on portions just below the crown, in the middle of the rhizome, and the median portions of three longer adventitious roots sampled from three plants in each area. The study reveals significant variations in vessel element characteristics of A. campestris, with roots consistently displaying longer and larger elements than rhizomes, and environmental conditions, especially in pine understory, influence vessel dimensions, and hydraulic conductivity in a negative manner.

Multi-trait association mapping for phosphorous efficiency reveals flexible root architectures in sorghum.

BACKGROUND: On tropical regions, phosphorus (P) fixation onto aluminum and iron oxides in soil clays restricts P diffusion from the soil to the root surface, limiting crop yields. While increased root surface area favors P uptake under low-P availability, the relationship between the three-dimensional arrangement of the root system and P efficiency remains elusive. Here, we simultaneously assessed allelic effects of loci associated with a variety of root and P efficiency traits, in addition to grain yield under low-P availability, using multi-trait genome-wide association. We also set out to establish the relationship between root architectural traits assessed in hydroponics and in a low-P soil. Our goal was to better understand the influence of root morphology and architecture in sorghum performance under low-P availability. RESULT: In general, the same alleles of associated SNPs increased root and P efficiency traits including grain yield in a low-P soil. We found that sorghum P efficiency relies on pleiotropic loci affecting root traits, which enhance grain yield under low-P availability. Root systems with enhanced surface area stemming from lateral root proliferation mostly up to 40 cm soil depth are important for sorghum adaptation to low-P soils, indicating that differences in root morphology leading to enhanced P uptake occur exactly in the soil layer where P is found at the highest concentration. CONCLUSION: Integrated QTLs detected in different mapping populations now provide a comprehensive molecular genetic framework for P efficiency studies in sorghum. This indicated extensive conservation of P efficiency QTL across populations and emphasized the terminal portion of chromosome 3 as an important region for P efficiency in sorghum. Increases in root surface area via enhancement of lateral root development is a relevant trait for sorghum low-P soil adaptation, impacting the overall architecture of the sorghum root system. In turn, particularly concerning the critical trait for water and nutrient uptake, root surface area, root system development in deeper soil layers does not occur at the expense of shallow rooting, which may be a key reason leading to the distinctive sorghum adaptation to tropical soils with multiple abiotic stresses including low P availability and drought.

Anatomical features of ecological importance and taxonomic value revealed by scanning electron microscopy and light microscopy in Camonea umbellata (L.) A.R. Simões & Staples (Convolvulaceae).

This article describes detailed and novel data on the anatomy and histochemistry of leaves, stems, and roots of Camonea umbellata (L.) A.R.Simões & Staples in different environments for the identification of characters with taxonomical value and of ecological importance, with provision of light and scanning electron microscopy images. To analyze the characters, we collected samples of the vegetative organs of three individuals in each of three populations, which were in a grazing area, an urban environment, and a biological reserve. The main diagnostic anatomical markers for the identification of C. umbellata include amphistomatic leaves, tetracytic and brachyparatetracytic stomata, peltate trichomes, long simple trichomes, epidermis with striated cuticle ornamentation, mesophyll with acute borders, presence of druses, secretory channels, angular collenchyma, fibrous pericycle in the stem, intraxylary phloem in the vegetative organs, oil bodies throughout the midrib, petiole, stem and root, and epicuticular waxes of the crust and coiled rodlet types. Since the characters above did not show variation in the environments evaluated, we consider these characters taxonomically useful for the identification of C. umbellata. RESEARCH HIGHLIGHTS: The anatomy of the aerial vegetative organs of Camonnea umbellata retains common Convolvulaceae characters. The sinuosity of the epidermal cell walls and the density of trichomes in the epidermis of the petiole were visually variable characters among the analyzed individuals. Amphistomatic leaves, tetracytic and brachyparatetracytic stomata, peltate trichomes, epidermis with striated cuticle ornamentation, dorsiventral mesophyll with border acute, presence of druses, secretory structures, angular collenchyma, fibrous pericycle in the stem, intraxillary phloem, presence of oil bodies in all organs, and epicuticular waxes of the crust type and coiled rods were considered important anatomical markers for the recognition and correct identification of Camonea umbellata.

Insights on Molecular Characteristics of Hydrochars by 13C-NMR and Off-Line TMAH-GC/MS and Assessment of Their Potential Use as Plant Growth Promoters.

Hydrochar is a carbon-based material that can be used as soil amendment. Since the physical-chemical properties of hydrochar are mainly assigned to process parameters, we aimed at evaluating the organic fraction of different hydrochars through 13C-NMR and off-line TMAH-GC/MS. Four hydrochars produced with sugarcane bagasse, vinasse and sulfuric or phosphoric acids were analyzed to elucidate the main molecular features. Germination and initial growth of maize seedlings were assessed using hydrochar water-soluble fraction to evaluate their potential use as growth promoters. The hydrochars prepared with phosphoric acid showed larger amounts of bioavailable lignin-derived structures. Although no differences were shown about the percentage of maize seeds germination, the hydrochar produced with phosphoric acid promoted a better seedling growth. For this sample, the greatest relative percentage of benzene derivatives and phenolic compounds were associated to hormone-like effects, responsible for stimulating shoot and root elongation. The reactions parameters proved to be determinant for the organic composition of hydrochar, exerting a strict influence on molecular features and plant growth response.

Anatomical changes in stem and root of soybean plants submitted to salt stress.

The soybean is a legume that is widely cultivated in many countries due to the high levels of protein and oil contained in its seed, and is used for human and animal nutrition. However, salinity affects more than 800 million hectares worldwide, limiting global agricultural production. The aim of this research was to evaluate the structural behaviour of the roots and stems under progressive salt stress, detailing the possible anatomical modifications to these organs in soybean plants during this stress. The plants were randomized into five treatments (0, 50, 100, 150 and 200 mm NaCl). All the root regions studied and exposed to 100 mm Na+ exhibited increases in the epidermis and endodermis and formation of lysogenic aerenchyma with increasing salinity, revealing the protective roles of these structures in reducing Na+ influx. In the stem, increases in the cortex and pith in the first internode subject to 100 mm Na+ suggest anatomical responses that aim to minimize oxidative stress. Soybean plants subjected to progressive salt stress (>50 mm Na+ ) avoided cavitation and loss of function linked to vessel elements, reducing the metaxylem in all the root and stem regions analysed. Finally, our results confirm anatomical changes to the roots and stems.

Competition at the soybean V6 stage affects root morphology and biochemical composition.

The experiment was conducted in the 2016/17 crop season in a greenhouse at Passo Fundo University, Brazil. We hypothesised that the morphological characteristics and biochemical and anatomical composition of soybean roots and shoots, when competing with weeds during different growth periods, are negatively affected, so current concepts of competition between plants should also consider changes in plant roots. The soybean cultivar P 95R51 and horseweed (Conyza bonariensis) were used. The treatments consisted of the presence or absence of weeds during different coexistence periods of soybean with horseweed. The periods were V0-V3, V0-V6, V0-R2, V3-R6, V6-R6 and R2-R6, where V0 was the date of soybean sowing and V3, V6, R2 and R6 were phenological stages of the crop. Two fresh roots were used to examine morphological traits. Four roots were used for quantification of dry matter and secondary metabolites. Root length was reduced by 21%, 14% and 20% when competing with a weed in the V0-V3, V0-V6 and R2-R6 coexistence periods, respectively. Total phenol content in the V0-V6 and V0-R2 periods was reduced when plants were in competition with weeds; a similar trend was found for flavonoids in the V0-V6 period. Soybean-horseweed competition from crop emergence to the V6 stage, in general, affects shoot and root morphological traits and the biochemical composition of the soybean roots. The presence of horseweed at the V3, V6 and R2 stages does not negatively alter the traits evaluated. Root anatomical composition is not modified during all coexistence periods with horseweed.

Anatomical Characterization of Nine Taxa of Genus Acmella Rich. (Toothache Plant) in India

Abstract The present study is aimed for anatomical characterization of nine taxa of Acmella to supplement data specifically for its current sectional classification and species circumscriptions. Anatomical characterization of this genus is little explored. This study focuses on internal structure of leaves, petioles, peduncles, stems, roots and cell inclusions to determine its taxonomic importance. In stem anatomy the number of hypodermal collenchymatous layers and the arrangement of parenchymatous cortex together place an important role in the identification of Acmella. Root anatomy was similar in all the examined taxa except in the arrangement of xylem vessels. In A. tetralobata xylem vessels arranged in pentarch fashion while rest of the species possess tetrarch arrangement. Several cellular inclusions such as calcium oxalate crystals and oil bodies were observed. The petioles were crescent shaped having bifacial surfaces with both surfaces pubescent. Peduncles possess ridges and furrows in its outline. The leaves are dorsi ventral and possess single layered epidermal cells covered with cuticle having anomocytic, anisocytic and diacytic types of stomata in both adaxial and abaxial surfaces. The present study provides a tool for the microscopic identification of the genus.

Anatomical and histochemical comparison of the primary and adventitious roots of Attalea microcarpa (Arecaceae) at the initial growth stage / Comparação anatômica e histoquímica entre raízes primária e adventícia de Attalea microcarpa (Arecaceae) em estádio inicial de crescimento

We describe the anatomical structure of roots originating from the apocole of Attalea microcarpa compared to the primary root, by means of usual methods for optical microscopy. The adventitious roots are differentiated in the apocole associated to vascular bundles, and can remain as a single structure or branch. They have the basic root structure characteristic of Arecoideae palms, without schizogenous spaces, which are observed in the primary root, in addition to few air spaces. Mucilages, starch and proteins were present in both types of roots. Adventitious roots of the apocole are described for the first time in Arecaceae.(AU)

Este estudo descreve a estrutura anatômica de raízes originárias do apocole de Attalea microcarpa, em comparação à raiz primária por meio de técnicas usuais para microscopia óptica. As raízes adventícias são diferenciadas no apocole, associadas a feixes vasculares, e podem se manter como uma estrutura única ou se ramificar. Possuem a estrutura básica das raízes de palmeiras Arecoideae, com ausência de dutos, que são observados na raiz primária, além de poucos espaços de ar. Mucilagens, amido e proteínas foram detectados em ambos os tipos de raízes. Raízes adventícias da região do apocole são descritas pela primeira vez em Arecaceae.(AU)

Initial shoot development and root architecture of citrus rootstocks / Desenvolvimento inicial de parte aérea e arquitetura de raiz de porta-enxertos de citros

A well-developed root system is a very important characteristic of rootstocks. Initial plant characterization is a potential technique to highlight cultivars with desirable root architecture for the diversification of rootstocks in the national citriculture. Thus, the aim of this study was to evaluate the initial shoot development and root architecture of citrus cultivars used as rootstocks. Seeds from five rootstocks, ‘Cleopatra’ mandarin, ‘Rangpur’ lime, ‘Rough’ lemon, ‘C13’ and ‘Troyer’ citranges, were sown in black polyethylene bags. A completely randomized block design with five replications and one plant per plot was applied. At 30 and 45 days after emergence, shoots and roots were collected for analysis. Shoot analysis measured the total number of leaves, leaf area, stem diameter, plant height, and fresh and dry matter weights. Root analysis evaluated fresh and dry matter weights and root architecture by image analysis, which recorded root traits including primary, secondary, and tertiary root numbers; length and total volume; and the percentage of secondary roots present in the upper third of the primary root. Shoot and root data of fresh and dry weights were submitted to variance analysis and compared using Tukey’s test (5%). The remaining root data were standardized for variance 1 and studied through principal component analysis. The ‘C13’ citrange showed good shoot development, with greater leaf area, plant height, stem diameter, and shoot fresh and dry matter weights during both evaluation periods, followed by the ‘Troyer’ citrange. The ‘Cleopatra’ mandarin had the smallest shoot and root development during both evaluation periods, presenting lower primary root, secondary root, and root volume than other cultivars evaluated at the same time. The ‘Troyer’ citrange had fewer roots in the upper third of the primary root and a higher root insertion angle.

Um sistema radicular bem desenvolvido é uma característica muito importante dos porta-enxertos. A caracterização inicial das plantas é uma técnica que apresenta potencial para detecção de cultivares com arquitetura desejável de raízes para uso na diversificação dos porta-enxertos da citricultura nacional. Com isso, o objetivo do estudo foi avaliar o desenvolvimento inicial da parte aérea e a arquitetura de raiz de cinco cultivares de citros usadas como porta-enxertos. Sementes de cinco porta-enxertos, tangerina ‘Cleópatra’, limão ‘Cravo’, limão ‘Rugoso’, citrange ‘C13’ e ‘Troyer’, foram semeadas em sacolas pretas de polietileno. Foi utilizado delineamento experimental de blocos inteiramente casualizados, com cinco repetições e uma planta por bloco. Aos 30 e 45 dias após emergência a parte aérea e as raízes foram coletadas para análise. As análises de parte aérea avaliaram número total de folhas, área foliar, diâmetro do caule, altura da planta, massa fresca e seca. Análises de raízes avaliaram massa fresca e seca e arquitetura de raízes por análise de imagem, que avaliou características como, número de raízes primárias, secundários e terciárias, comprimento e volume total de raízes e porcentagem de raízes secundárias presentes no primeiro terço da raiz principal. Os dados de parte aérea e massa fresca e seca de raiz foram submetidos à análise de variância e comparados usando teste de Tukey (5%). O restante dos dados de raiz foram padronizados para a variância 1 e estudados pela análise de componentes principais. O citrange ‘C13’ apresentou bom desenvolvimento de parte aérea, com maior área foliar, altura de planta, diâmetro de caule e massa fresca e seca de parte aérea em ambos períodos avaliados, seguido pelo citrange 'Troyer'...

Initial shoot development and root architecture of citrus rootstocks / Desenvolvimento inicial de parte aérea e arquitetura de raiz de porta-enxertos de citros

A well-developed root system is a very important characteristic of rootstocks. Initial plant characterization is a potential technique to highlight cultivars with desirable root architecture for the diversification of rootstocks in the national citriculture. Thus, the aim of this study was to evaluate the initial shoot development and root architecture of citrus cultivars used as rootstocks. Seeds from five rootstocks, ‘Cleopatra mandarin, ‘Rangpur lime, ‘Rough lemon, ‘C13 and ‘Troyer citranges, were sown in black polyethylene bags. A completely randomized block design with five replications and one plant per plot was applied. At 30 and 45 days after emergence, shoots and roots were collected for analysis. Shoot analysis measured the total number of leaves, leaf area, stem diameter, plant height, and fresh and dry matter weights. Root analysis evaluated fresh and dry matter weights and root architecture by image analysis, which recorded root traits including primary, secondary, and tertiary root numbers; length and total volume; and the percentage of secondary roots present in the upper third of the primary root. Shoot and root data of fresh and dry weights were submitted to variance analysis and compared using Tukeys test (5%). The remaining root data were standardized for variance 1 and studied through principal component analysis. The ‘C13 citrange showed good shoot development, with greater leaf area, plant height, stem diameter, and shoot fresh and dry matter weights during both evaluation periods, followed by the ‘Troyer citrange. The ‘Cleopatra mandarin had the smallest shoot and root development during both evaluation periods, presenting lower primary root, secondary root, and root volume than other cultivars evaluated at the same time. The ‘Troyer citrange had fewer roots in the upper third of the primary root and a higher root insertion angle.(AU)

Um sistema radicular bem desenvolvido é uma característica muito importante dos porta-enxertos. A caracterização inicial das plantas é uma técnica que apresenta potencial para detecção de cultivares com arquitetura desejável de raízes para uso na diversificação dos porta-enxertos da citricultura nacional. Com isso, o objetivo do estudo foi avaliar o desenvolvimento inicial da parte aérea e a arquitetura de raiz de cinco cultivares de citros usadas como porta-enxertos. Sementes de cinco porta-enxertos, tangerina ‘Cleópatra, limão ‘Cravo, limão ‘Rugoso, citrange ‘C13 e ‘Troyer, foram semeadas em sacolas pretas de polietileno. Foi utilizado delineamento experimental de blocos inteiramente casualizados, com cinco repetições e uma planta por bloco. Aos 30 e 45 dias após emergência a parte aérea e as raízes foram coletadas para análise. As análises de parte aérea avaliaram número total de folhas, área foliar, diâmetro do caule, altura da planta, massa fresca e seca. Análises de raízes avaliaram massa fresca e seca e arquitetura de raízes por análise de imagem, que avaliou características como, número de raízes primárias, secundários e terciárias, comprimento e volume total de raízes e porcentagem de raízes secundárias presentes no primeiro terço da raiz principal. Os dados de parte aérea e massa fresca e seca de raiz foram submetidos à análise de variância e comparados usando teste de Tukey (5%). O restante dos dados de raiz foram padronizados para a variância 1 e estudados pela análise de componentes principais. O citrange ‘C13 apresentou bom desenvolvimento de parte aérea, com maior área foliar, altura de planta, diâmetro de caule e massa fresca e seca de parte aérea em ambos períodos avaliados, seguido pelo citrange 'Troyer'...(AU)

Rice seeds vigor through image processing of seedlings / Determinação do vigor de sementes de arroz através do processamento de imagens de plântulas

The aim of this paper was to verify the viability of digital image processing in the measurement of rice seedling and its potential use as seed vigor test. The experiment took place at the Laboratório Didático de Análise de Sementes, located in Capão do Leão (RS), using seeds of eight rice cultivars: Irga 424, Puitá Inta CL, BRS Esmeralda, SCS 116, Guri Inta CL, BRS Pampa, BRSGO Serra Dourada and Olimar. An image processing system (IPS) was used to measure length and area of shoot and root as an index of seed vigor in rice seeds. The experiment design was completely randomized with five replications. The evaluated variables were root and shoot length in graded ruler and by image, root and shoot area, and field emergence. Results obtained with the IPS were correlated with other quality tests though the Pearson tests. Determination of shoot length and leaf area of the seedlings obtained through IPS is effective for assessing the vigor of rice seeds.(AU)

O objetivo neste trabalho foi verificar a viabilidade do processamento digital de imagens na mensuração de plântulas de arroz e sua potencial utilização como teste de vigor em sementes. O experimento foi realizado no Laboratório Didático de Análise de Sementes, localizado no Capão do Leão (RS), utilizando sementes de oito cultivares de arroz: Irga 424, Puitá Inta CL, BRS Esmeralda, SCS 116, Guri Inta CL, BRS Pampa, BRSGO Serra Dourada e Olimar. Uma ferramenta de processamento de imagens (FPI) foi utilizada para mensurar o comprimento e a área da parte aérea e de raízes de plântulas de arroz de modo a classificar as sementes em níveis de vigor. O delineamento experimental foi inteiramente casualizado com cinco repetições. As variáveis avaliadas foram comprimento de raiz e parte aérea em régua graduada e pela imagem, área de raiz e parte aérea e emergência a campo. Os resultados obtidos com o FPI foram correlacionados com outros testes de qualidade por correlação de Pearson. A determinação do comprimento de parte aérea e área foliar de plântulas obtidos através do FPI é efetivo para avaliar o vigor de sementes de arroz.(AU)

Multiplicação do sabugueiro por estaquia de acordo com o tipo de estaca e concentração de ácido indolbutírico / Multiplication of the sabugueiro by stacking according to the type of cutting and concentration of indolbutyric acid

O objetivo foi avaliar a multiplicação do sabugueiro (Sambucus australis) de acordo com o tipo de estaca e concentração de ácido indolbutírico (AIB) pela técnica de estaquia. O trabalho foi realizado na Unidade de Ensino e Pesquisa Horta de Plantas medicinais, da Universidade Tecnológica Federal do Paraná – Campus Dois Vizinhos (PR). O delineamento experimental foi inteiramente casualizado, em esquema fatorial 2 x 5 (tipo de estaca x concentração de AIB), com 4 repetições de 10 estacas por unidade experimental. Os ramos foram preparados em estacas de 8 cm, mantendo-se um par de folhas reduzido a 25% do tamanho original. As estacas foram preparadas de dois tipos de ramos (Herbácea e Semi-lenhosa). Posteriormente a base das estacas foram tratadas com solução de AIB, nas concentrações 0, 500, 1000, 1500 e 2000 mg L-1, durante 10 segundos e colocadas em tubetes redondos contendo substrato comercial. Aos 60 dias da implantação do experimento foram avaliados o enraizamento das estacas, número médio de raízes por estaca, comprimento médio de raiz, número médio de brotações por estaca, comprimento médio das brotações, massa de matéria fresca da parte aérea e radicular e massa de matéria seca da parte aérea e radicular. Das estacas enraizadas, foram escolhidas 5 aleatoriamente de cada tratamento, sendo replantadas em tubetes para avaliar a sobrevivência 30 dias após a avaliação. Para a multiplicação do sabugueiro (Sambucus australis) pela técnica de estaquia não é recomendada a aplicação exógena de AIB, de maneira que as estacas podem ser confeccionadas de material herbáceo e semi-lenhoso.

The objective of this study was to evaluate the multiplication of elderberry (Sambucus australis) according to the cutting type and indolbutyric acid concentration (IBA) by cutting technique. The work was carried out at the Horta Teaching and Research Unit of Medicinal Plants, Universidade Tecnológica Federal do Paraná - Campus Dois Vizinhos (PR). The experimental design was completely randomized, in a 2 x 5 factorial scheme (stake type x IBA concentration), with 4 replicates of 10 cuttings per experimental unit. The branches were prepared on 8 cm cuttings, keeping a pair of leaves reduced to 25% of the original size. The cuttings were prepared from two types of branches (Herbaceous and Semi-woody). Subsequently the base of the cuttings were treated with IBA solution at the concentrations 0, 500, 1000, 1500 and 2000 mg L-1, for 10 seconds and placed in round tubes containing commercial substrate. Sixty days after the implantation of the experiment were evaluated the rooting of the cuttings, average number of roots per cutting, average length of root, average number of shoots per shoot, average shoot length, fresh shoot and root mass and dry matter of shoot and root. From the rooted cuttings, 5 were chosen randomly from each treatment and were replanted in tubes to evaluate the survival 30 days after the evaluation. For the multiplication of the elderberry (Sambucus australis) by the cutting technique, the exogenous application of IBA is not recommended, so that the cuttings can be made of herbaceous and semi-woody material.

Multiplicação do sabugueiro por estaquia de acordo com o tipo de estaca e concentração de ácido indolbutírico / Multiplication of the sabugueiro by stacking according to the type of cutting and concentration of indolbutyric acid

O objetivo foi avaliar a multiplicação do sabugueiro (Sambucus australis) de acordo com o tipo de estaca e concentração de ácido indolbutírico (AIB) pela técnica de estaquia. O trabalho foi realizado na Unidade de Ensino e Pesquisa Horta de Plantas medicinais, da Universidade Tecnológica Federal do Paraná Campus Dois Vizinhos (PR). O delineamento experimental foi inteiramente casualizado, em esquema fatorial 2 x 5 (tipo de estaca x concentração de AIB), com 4 repetições de 10 estacas por unidade experimental. Os ramos foram preparados em estacas de 8 cm, mantendo-se um par de folhas reduzido a 25% do tamanho original. As estacas foram preparadas de dois tipos de ramos (Herbácea e Semi-lenhosa). Posteriormente a base das estacas foram tratadas com solução de AIB, nas concentrações 0, 500, 1000, 1500 e 2000 mg L-1, durante 10 segundos e colocadas em tubetes redondos contendo substrato comercial. Aos 60 dias da implantação do experimento foram avaliados o enraizamento das estacas, número médio de raízes por estaca, comprimento médio de raiz, número médio de brotações por estaca, comprimento médio das brotações, massa de matéria fresca da parte aérea e radicular e massa de matéria seca da parte aérea e radicular. Das estacas enraizadas, foram escolhidas 5 aleatoriamente de cada tratamento, sendo replantadas em tubetes para avaliar a sobrevivência 30 dias após a avaliação. Para a multiplicação do sabugueiro (Sambucus australis) pela técnica de estaquia não é recomendada a aplicação exógena de AIB, de maneira que as estacas podem ser confeccionadas de material herbáceo e semi-lenhoso.(AU)

The objective of this study was to evaluate the multiplication of elderberry (Sambucus australis) according to the cutting type and indolbutyric acid concentration (IBA) by cutting technique. The work was carried out at the Horta Teaching and Research Unit of Medicinal Plants, Universidade Tecnológica Federal do Paraná - Campus Dois Vizinhos (PR). The experimental design was completely randomized, in a 2 x 5 factorial scheme (stake type x IBA concentration), with 4 replicates of 10 cuttings per experimental unit. The branches were prepared on 8 cm cuttings, keeping a pair of leaves reduced to 25% of the original size. The cuttings were prepared from two types of branches (Herbaceous and Semi-woody). Subsequently the base of the cuttings were treated with IBA solution at the concentrations 0, 500, 1000, 1500 and 2000 mg L-1, for 10 seconds and placed in round tubes containing commercial substrate. Sixty days after the implantation of the experiment were evaluated the rooting of the cuttings, average number of roots per cutting, average length of root, average number of shoots per shoot, average shoot length, fresh shoot and root mass and dry matter of shoot and root. From the rooted cuttings, 5 were chosen randomly from each treatment and were replanted in tubes to evaluate the survival 30 days after the evaluation. For the multiplication of the elderberry (Sambucus australis) by the cutting technique, the exogenous application of IBA is not recommended, so that the cuttings can be made of herbaceous and semi-woody material.(AU)

Review: Phytostimulation and root architectural responses to quorum-sensing signals and related molecules from rhizobacteria.

Bacteria rely on chemical communication to sense the environment and to retrieve information on their population densities. Accordingly, a vast repertoire of molecules is released, which synchronizes expression of genes, coordinates behavior through a process termed quorum-sensing (QS), and determines the relationships with eukaryotic species. Already identified QS molecules from Gram negative bacteria can be grouped into two main classes, N-acyl-L-homoserine lactones (AHLs) and cyclodipeptides (CDPs), with roles in biofilm formation, bacterial virulence or symbiotic interactions. Noteworthy, plants detect each of these molecules, change their own gene expression programs, re-configurate root architecture, and activate defense responses, improving in this manner their adaptation to natural and agricultural ecosystems. AHLs may act as alarm signals, pathogen and/or microbe-associated molecular patterns, whereas CDPs function as hormonal mimics for plants via their putative interactions with the auxin receptor Transport Inhibitor Response1 (TIR1). A major challenge is to identify the molecular pathways of QS-mediated crosstalk and the plant receptors and interacting proteins for AHLs, CDPs and related signals.

Biochar in sugar beet production and nutrition / Biochar na produção e nutrição da beterraba

The biomass pyrolysis process may be an alternative for the agricultural use of sewage sludge. This study aimed to evaluate the use of of biochars from mixture of sewage sludge and sugarcane bagasse (BB, 1:1 relationship sewage sludge and sugarcane bagasse) on sugar beet (Beta vulgaris L.) production and nutrition. A greenhouse experiment was conducted with five application rates of BB: 0, 2.5, 5, 7.5, and 10% (v/v), and two additional treatments, biochar from sewage sludge (BS, application rate 5% (v/v)) and conventional treatment (CV) that received lime and mineral fertilizer. The treated soils were incubated for 45 days, after which, seedlings were cultivated for 55 days. Biochar produce from sewage sludge and sugarcane bagasse is an alternative technology to reduce the potential for contamination of sewage sludge and to incorporate more stable carbon forms in the soil. Although, biochar has increased soil fertility, fine roots and nutrient uptake efficiency by sugar beet plants, total dry matter yield was significantly lower than that obtained in conventional treatment.(AU)

O processo de pirólise da biomassa pode ser uma alternativa para o uso agrícola de lodo de esgoto. Este trabalho objetivou avaliar o uso de biochar produzido a partir da mistura de lodo de esgoto e bagaço de cana (BB, 1:1 relação lodo de esgoto e e bagaço de cana) na produção e nutrição de beterraba (Beta vulgaris L.). Conduziu-se um experimento em casa de vegetação com cinco dose de BB: 0, 2,5, 5, 7,5 e 10% v/v, e dois tratamentos adicionais, biochar de lodo de esgoto (BS, 5% v/v) e tratamento convencional (CV) com calagem e fertilizantes minerais. Após 45 dias de incubação dos solos tratados, cultivou-se as plantas por 55 dias. O biochar produzido a partir de lodo de esgoto e bagaço de cana-de-açúcar é uma tecnologia alternativa para reduzir o potencial de contaminação do lodo de esgoto e incorporar formas mais estáveis de carbono ao solo. Embora o biochar tenha aumentado à fertilidade do solo, as raízes finas e a eficiência de absorção de nutrientes pelas plantas de beterraba, a produção de matéria seca total foi significativamente menor que a obtida no tratamento convencional.(AU)

Selenium downregulates auxin and ethylene biosynthesis in rice seedlings to modify primary metabolism and root architecture.

MAIN CONCLUSION: Selenium modulates the formation of primary and lateral roots through alterations in auxin and ethylene, leading to new patterns of root architecture in rice seedlings. Selenium (Se) at low concentrations can control root growth through interaction with hormone biosynthesis. Auxin and ethylene have been shown to control the root architecture, with most of the information obtained from the eudicots such Arabidopsis and Nicotiana tabacum. Here, we presented the effects of Se on auxin and ethylene pathways and examined their impact on primary metabolism and root system architecture in rice (Oryza sativa L.) seedlings. Se treatment increased elongation of primary root, but decreased the number and length of lateral roots. Se led to decreased expression of genes associated with the biosynthesis of auxin and ethylene, concomitantly with reduced production of these hormones by the roots. Moreover, Se decreased the abundance of transcripts encoding auxin transport proteins. Indole-3-acetic acid (IAA) treatment overrode the repressive effect of Se on lateral root growth. The ethylene synthesis inhibitor L-α-(2-aminoethoxyvinyl)-glycine (AVG) increased elongation of primary root, whereas the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) resulted in the opposite effect. Soluble sugars accumulate in roots of rice seedlings under Se treatment. Thus, Se modulates the formation of primary and lateral roots through alterations in auxin and ethylene, leading to new patterns of root architecture in rice seedlings.

Structure and development of root gall induced by Meloidogyne javanica in Glycine max L / Estrutura e desenvolvimento da galha radicular induzida por Meloidogyne javanica em Glycine max L

Galls formed by root-knot nematodes have been studied in several cultivated species focusing on understanding the intimate relationship between parasite and the host plant. Species of Meloidogyne induce the development of a feeding site in the cortex or vascular cylinder of the host plant and are totally dependent on this site formation to complete their life cycle. Therefore, we focused on anatomical, cytological and histochemical changes during the establishment and development of galls and giant cells induced by Meloidogyne javanica in the roots of Glycine max. Seeds of soybean (susceptible cultivar M8372 IPRO) were sown in trays with coconut fibre substrate and the seedlings were removed ten days after the seeds emerged for nematode inoculation. The roots from inoculated and non-inoculated (control) were sampled at different stages of development until 55 days after inoculation. Histological, cytological, histochemical analysis were performed in light and electron microscopy in non-galled tissue and galls induced by M. javanica. The galls showed different shapes and abundance in the roots inoculated by M. javanica. The induction of galls occurs by hypertrophy of the root cortex shortly after the initial infection process. Giant cells were formed 18 days after nematode inoculation. These giant or nourishing cells are multinucleated, and have a dense cytoplasm, a thick wall with invaginations, many mitochondria and small vacuoles. The anatomical sections indicated a disorganisation of the cells of the cortex and vascular cylinder in relation to the control root.

Galhas radiculares induzidas por nematoides têm sido estudadas em diversas espécies cultivadas, fornecendo subsídios para a compreensão da íntima relação entre parasita e hospedeiro. O estabelecimento do nematoide das galhas passa, necessariamente, pelo processo de formação das células gigantes, que garantem a nutrição do nematoide. As espécies de Meloidogyne estabelecem um sitio de alimentação no córtex ou cilindro vascular da raiz, sendo esses organismos totalmente dependentes deste sítio de indução. Desta forma o objetivo deste trabalho foi avaliar as alterações anatômicas, citológicas e histoquímicas durante o desenvolvimento de galhas induzidas por Meloidogyne javanica em raízes de Glycine max. A variedade de soja utilizada foi a M8372 IPRO, susceptível ao nematoide M. javanica. As sementes foram semeadas em bandejas e depois colocadas em tubetes, onde foram realizadas coletas de amostras radiculares em diferentes estádios de desenvolvimento, tanto de plantas inoculadas com o nematoide quanto de plantas controle. As amostras de galhas e raízes não galhadas foram utilizadas para as análises histológicas, citológicas e histoquímicas, em microscopia óptica e eletrônica. Verificou-se a presença de galhas após a inoculação de M. javanica, com variação na quantidade e na forma. A indução das galhas ocorre pela hipertrofia do córtex da raiz, logo após o processo inicial de infecção. Aos18 dias após a inoculação do nematoide já é possível observar a formação de células gigantes. Estas células gigantes ou nutridoras são multinucleadas, possuem citoplasma denso, parede espessa com invaginações, muitas mitocôndrias e pequenos vacúolos. As secções anatômicas indicaram uma desorganização das células do córtex e cilindro vascular em relação à raiz não inoculada (controle).

Structure and development of root gall induced by Meloidogyne javanica in Glycine max L / Estrutura e desenvolvimento da galha radicular induzida por Meloidogyne javanica em Glycine max L

Galls formed by root-knot nematodes have been studied in several cultivated species focusing on understanding the intimate relationship between parasite and the host plant. Species of Meloidogyne induce the development of a feeding site in the cortex or vascular cylinder of the host plant and are totally dependent on this site formation to complete their life cycle. Therefore, we focused on anatomical, cytological and histochemical changes during the establishment and development of galls and giant cells induced by Meloidogyne javanica in the roots of Glycine max. Seeds of soybean (susceptible cultivar M8372 IPRO) were sown in trays with coconut fibre substrate and the seedlings were removed ten days after the seeds emerged for nematode inoculation. The roots from inoculated and non-inoculated (control) were sampled at different stages of development until 55 days after inoculation. Histological, cytological, histochemical analysis were performed in light and electron microscopy in non-galled tissue and galls induced by M. javanica. The galls showed different shapes and abundance in the roots inoculated by M. javanica. The induction of galls occurs by hypertrophy of the root cortex shortly after the initial infection process. Giant cells were formed 18 days after nematode inoculation. These giant or nourishing cells are multinucleated, and have a dense cytoplasm, a thick wall with invaginations, many mitochondria and small vacuoles. The anatomical sections indicated a disorganisation of the cells of the cortex and vascular cylinder in relation to the control root.(AU)

Galhas radiculares induzidas por nematoides têm sido estudadas em diversas espécies cultivadas, fornecendo subsídios para a compreensão da íntima relação entre parasita e hospedeiro. O estabelecimento do nematoide das galhas passa, necessariamente, pelo processo de formação das células gigantes, que garantem a nutrição do nematoide. As espécies de Meloidogyne estabelecem um sitio de alimentação no córtex ou cilindro vascular da raiz, sendo esses organismos totalmente dependentes deste sítio de indução. Desta forma o objetivo deste trabalho foi avaliar as alterações anatômicas, citológicas e histoquímicas durante o desenvolvimento de galhas induzidas por Meloidogyne javanica em raízes de Glycine max. A variedade de soja utilizada foi a M8372 IPRO, susceptível ao nematoide M. javanica. As sementes foram semeadas em bandejas e depois colocadas em tubetes, onde foram realizadas coletas de amostras radiculares em diferentes estádios de desenvolvimento, tanto de plantas inoculadas com o nematoide quanto de plantas controle. As amostras de galhas e raízes não galhadas foram utilizadas para as análises histológicas, citológicas e histoquímicas, em microscopia óptica e eletrônica. Verificou-se a presença de galhas após a inoculação de M. javanica, com variação na quantidade e na forma. A indução das galhas ocorre pela hipertrofia do córtex da raiz, logo após o processo inicial de infecção. Aos18 dias após a inoculação do nematoide já é possível observar a formação de células gigantes. Estas células gigantes ou nutridoras são multinucleadas, possuem citoplasma denso, parede espessa com invaginações, muitas mitocôndrias e pequenos vacúolos. As secções anatômicas indicaram uma desorganização das células do córtex e cilindro vascular em relação à raiz não inoculada (controle).(AU)

Associative bacteria influence maize (Zea mays L.) growth, physiology and root anatomy under different nitrogen levels.

Despite the great diversity of plant growth-promoting bacteria (PGPB) with potential to partially replace the use of N fertilisers in agriculture, few PGPB have been explored for the production of commercial inoculants, reinforcing the importance of identifying positive plant-bacteria interactions. Aiming to better understand the influence of PGPB inoculation in plant development, two PGPB species with distant phylogenetic relationship were inoculated in maize. Maize seeds were inoculated with Bacillus sp. or Azospirillum brasilense. After germination, the plants were subjected to two N treatments: full (N+) and limiting (N-) N supply. Then, anatomical, biometric and physiological analyses were performed. Both PGPB species modified the anatomical pattern of roots, as verified by the higher metaxylem vessel element (MVE) number. Bacillus sp. also increased the MVE area in maize roots. Under N+ conditions, both PGPB decreased leaf protein content and led to development of shorter roots; however, Bacillus sp. increased root and shoot dry weight, whereas A. brasilense increased photosynthesis rate and leaf nitrate content. In plants subjected to N limitation (N-), photosynthesis rate and photosystem II efficiency increased in maize inoculated with Bacillus sp., whilst A. brasilense contained higher ammonium, amino acids and total soluble sugars in leaves, compared to the control. Plant developmental and metabolical patterns were switched by the inoculation, regardless of the inoculant bacterium used, producing similar as well as distinct modifications to the parameters studied. These results indicate that even non-diazotrophic inoculant strains can improve the plant N status as result of the morpho-anatomical and physiological modifications produced by the PGPB.

Genetic and Phenotypic Analysis of Lateral Root Development in Arabidopsis thaliana.

Root system formation to a great extent depends on lateral root (LR) formation. In Arabidopsis thaliana, LRs are initiated within a parent root in pericycle that is an external tissue of the stele. LR initiation takes place in a strictly acropetal pattern, whereas posterior lateral root primordium (LRP) formation is asynchronous. In this chapter, we focus on methods of genetic and phenotypic analysis of LR initiation, LRP morphogenesis, and LR emergence in Arabidopsis. We provide details on how to make cleared root preparations and how to identify the LRP stages. We also pay attention to the categorization of the LRP developmental stages and their variations and to the normalization of the number of LRs and LRPs formed, per length of the primary root, and per number of cells produced within a root. Hormonal misbalances and mutations affect LRP morphogenesis significantly, and the evaluation of LRP abnormalities is addressed as well. Finally, we deal with various molecular markers that can be used for genetic and phenotypic analyses of LR development.