Shoot Matter Research Articles

Tolerance of crambe (Crambe abyssinica Hochst) to salinity and water stress during seed germination and initial seedling growth

ABSTRACT Crambe is an oilseed plant whose oil is suitable for various industrial purposes, such as production of biodiesel, plastics, rubbers, and cosmetics. There are reports of the rusticity of this species and its potential for growth in arid and semi-arid environments, where water scarcity and soil salinity are common. However, studies regarding the tolerance of its seeds to these stresses and the physiological responses triggered during germination and seedling establishment under these conditions are incipient. The objective of this study was to evaluate the tolerance of crambe seeds to water deficit and salt stress during germination and early seedling development, as well as to investigate the role of antioxidant enzymes on tolerance to these conditions. The seeds were exposed to water and salt stresses and their performance was analyzed. Seed water content, imbibition rate, percentage and speed of germination, and the base water potential for seed germination were evaluated. In the seedlings, the following measurements were made: root and shoot length, fresh and dry matter of roots and shoots, moisture content, and activity of the enzymes superoxide dismutase (SOD), catalase (CAT), and peroxidase (POX). Water deficit and salt stress reduce the water uptake rate of the seeds, the germination and growth of seedlings. The crambe seeds had higher tolerance to salt stress than to water deficit. Absorption of salt and the action of the SOD and CAT antioxidant enzymes are part of the tolerance mechanisms of crambe seeds to salt stress.

Initial development of Combretum leprosum Mart. seedlings irrigated with saline water of different cationic natures

This study aimed to evaluate the tolerance of C. leprosum seedlings to salt stress during the emergence and early seedling development. The experiment was carried out between the months of August and September, in a greenhouse, and the substrate used was the commercial coconut fiber wetted with aqueous solutions of sodium chloride (NaCl), calcium chloride (CaCl2) and potassium chloride (KCl) with the electrical conductivities of 0.0, 1.5, 2.5, 3.5, 4.5, 5.5 and 6.5 dS m-1. We used a completely randomized design in a 3 x 7 factorial scheme (three salts x seven levels of electrical conductivity). We evaluated seedling emergence, emergence speed index, root length, shoot length, dry matter of roots and shoots. The results indicated significant interaction between both factors analyzed. The emergence and initial growth of C. leprosum plants decrease gradually due to the increase of the electrical conductivity levels, with root length being less affected by waters salinized with CaCl and KCl. C. leprosum seedlings show sensitivity to the three types of salts and are highly sensitive to KCl and NaCl.

Poultry Litter for the Production and Quality of Enterolobium contortisiliquum Vell. Seedlings

ABSTRACT The objective of this work was to determine the efficiency of poultry litter ratios added to the commercial substrate and to peat in the growth and quality of Enterolobium contortisiliquum seedlings. The design was completely randomized, with 10 replications, in a 2 × 5 factorial arrangement with two substrates (peat and commercial substrate) and five poultry litter ratios, added (v:v) to both substrates (0, 25%, 50%, 75% and 100%). The height, stem diameter, dry matter of shoot and roots, root specific surface area, Dickson quality index and NPK accumulated in dry matter of shoot and roots were evaluated. Poultry litter can be added up to a 35% ratio to the commercial substrate or to peat for the production of Enterolobium contortisiliquum seedlings; proportions above this, for both substrates, compromise the production. The treatments with peat provided lower growth and quality of Enterolobium contortisiliquum seedlings, compared to the commercial substrate.

Interference of Brassicaceae and Poaceae on Canola Hybrids

ABSTRACT: The objective of this study was to evaluate the initial competitive ability of canola hybrids against Brassicaceae and Poaceae species in terms of root and shoot resources. Two experiments were conducted in greenhouse, in a completely randomized design with four replications. The treatments consisted of interference conditions by root + shoot interference (root+shoot) and shoot interference (Light); and Brassicaceae and Poaceae weeds competing with hybrid of canola (Hyola 61 and Diamond) with different traits for competitiveness. The plant height, root length, dry matter of shoot and root, number of leaves and leaf area were evaluated. Data were compared using orthogonal contrasts. The turnip and volunteer canola reduced root development of the Hyola 61 in root + shoot interference, and among the Brassicaceas weeds, turnip caused greater losses. Brassicaceas weeds caused largest reductions in Diamond’s hybrid growth compared to Poaceae, mainly under light interference. Brassicaceas and Poaceae weeds cause similar damage to Hyola 61 hybrid, and the injury is higher for root +shoot interference. The black oat induce shoot growth in the Diamond hybrid under shoot interference, while among the Brassicaceae weed species, there were no differences.

Brood parasitism of rosefinches by cuckoos: suitable host or accidental parasitism?

The arms race between avian brood parasites and their hosts is a classic model of co-evolution. Parasitic breeding by the common cuckoo (Cuculus canorus) in the nests of the Chinese beautiful rosefinch (Carpodacus davidianus) was found from May to July 2017 in Saihanba National Forest Park, Heibei, China. To understand whether the rosefinch is a suitable host species for the common cuckoo, egg recognition, chick recognition, brood rearing, and brood diets were studied. The results showed that rosefinches fully accepted non-mimetic white model eggs and parakeet (Melopsittacus undulatus) eggs, and also did not reject the similar-looking eggs of cinereous tits (Parus cinereus). Chinese beautiful rosefinches did not demonstrate any ability to recognize or discriminate between parasitic eggs or nestlings, and provisioned nestlings of cinereous tit, coal tit (Periparus ater), dusky warbler (Phylloscopus fuscatus), and common cuckoo within their nests. However, Chinese beautiful rosefinches were unable to rear the parasitic nestlings; dissections of deceased nestlings revealed that the food provided by Chinese beautiful rosefinch parents was largely composed of plant seeds and young plant shoot materials. This suggested that the high cross-fostered nestling mortality was due to unsuitable food provisioning from the host parents to the parasitic chicks. Therefore, we concluded that the Chinese beautiful rosefinch is not a suitable host for the common cuckoo, and this parasitic breeding system does not represent a co-evolutionary relationship.

RATES OF APPLICATION OF Azospirillum brasilense IN TOMATO CROP

The use of plant growth-promoting bacteria (PGPB) may be a promising agronomic practice to improve the growth and productivity of vegetables. The objective of this work was to evaluate the effect of inoculation of Azospirillum brasilense on plant growth and tomato fruit production. Two experiments were carried out: the first one evaluating the growth of the plants in a greenhouse and the second one evaluating the production of fruits under field conditions. The experimental design used in two experiments was the completely randomized 2 x 5 factorial scheme, with four replications. The treatments resulted from the combination of two tomato cultivars (Gaúcho Melhorado and San Marzano) and four inoculant doses (0; 2; 4; 6 e 8 mL kg-1 of seed) containing the Ab-V5 and Ab-V6 strains of A. Brasilense. The application of inoculant containing A. brasilense improved the growth and dry matter production of tomato cultivars Gaúcho Melhorado and San Marzano. The highest values of plant height, stem diameter, root length, root volume, relative chlorophyll content and dry matter of shoots and roots are obtained with the dose of 4 to 6 mL kg-1 of inoculant, allowing to infer that the maximization of plant growth and the production of tomato fruits with the application of inoculant containing Azospirillum brasilense can be obtained with the use of approximately 5.0 mL kg-1 of seeds for tomato cultivars.

GROWTH AND YIELD OF WHEAT IN RESPONSE TO SEED VIGOR AND SOWING DENSITIES

ABSTRACT In wheat crops, it is often observed that the number of plants per area is lower than that of viable seeds used, which may be related to both environmental conditions and seed vigor. The aim of this study was to assess the effect of seed vigor level at different sowing densities on growth, development, and grain yield in wheat cultivars. The experiments were conducted in Londrina and Ponta Grossa, PR, Brazil, under a randomized block design in a 2 × 2 × 3 factorial scheme, with four replications. Two seed vigor levels (high and low), two sowing densities (200 and 400 viable seeds per m2), and three wheat cultivars (BRS Sabiá, BRS Gaivota, and BRS Gralha Azul) were assessed. In order to assess growth and development, plant samples were collected at the phenological stages of seedling growth, stem elongation, booting, and ear emergence. We assessed the emergence of seedlings, height and dry matter of plant shoot, and grain yield. The sowing density of 200 seeds per m2 led to a higher shoot dry matter production per plant at the stages booting and ear emergence. The cultivar BRS Sabiá presented the highest grain yield in Londrina, while BRS Sabiá and BRS Gralha Azul presented the highest grain yield in Ponta Grossa. High vigor seeds favor stand establishment, growth and development of plants at early phenological stages, and grain yield of wheat.

Resíduos agrícolas incorporados a substrato comercial na produção de mudas de repolho

Na produção de hortaliças de qualidade a formação de mudas é uma das fases mais importantes para o ciclo da cultura, influenciando diretamente no desempenho final da planta, tanto do ponto de vista nutricional como produtivo. Um dos fatores decisivos para obtenção de mudas com qualidade e consequente aumento de produtividade é o tipo de substrato utilizado. O estudo objetivou avaliar o efeito de proporções crescentes de resíduos da secagem de grãos de café (moinha) em substratos alternativos compostos de fibra de coco, casca de ovo e substrato comercial, nas variáveis de crescimento de mudas de repolho. O delineamento experimental foi o inteiramente casualizado, com cinco tratamentos e dez repetições, sendo os tratamentos: T0: substrato comercial (testemunha); T1: 10% de moinha (MO) + 15% fibra de coco (FC) + 5% casca de ovo (CO) + 70% substrato comercial (SC); T2: 20% de MO + 15% FC + 5% CO + 60% SC; T3: 30% de MO + 15% FC + 5% CO + 50% SC; T4: 40% de MO + 15% FC + 5% CO + 40% SC. As variáveis avaliadas foram condutividade elétrica do substrato, diâmetro de coleto, número de folhas, altura de plantas e matérias secas da parte aérea, raiz e total de planta. Os maiores valores obtidos das variáveis analisadas foram obtidos no tratamento 4, no qual se utilizou-se 40% de moinha + 15% fibra de coco + 5% casca de ovo + 40% substrato comercial.

Desenvolvimento de angelônia em vaso, sob doses de adubo de liberação lenta

Angelonia integerrima is a native species that has ornamental potential, being cultivated in flowerbeds, flowerpots, pots, or even used as a complement in floral arrangements. Knowledge of mineral nutrition is required for the cultivation of the species, and slow release fertilization have become widespread in recent years, with a lower risk of toxicity to crops, an economy in relation to complementary fertilizers and may be an alternative to cultivation of potted plants. The aim of this study was to evaluate the development of Angelonia integerrima Sprengel in pot under slow release fertilization doses. Acclimatized seedlings with approximately 1 cm height, from in vitro germinated seeds were transplanted into 1 L pots containing substrate composted Pinus bark. Five doses of Basacote ® 9M slow release fertilizer, formulation 16-8-12 (N - P2O5 - K2O), 9 months: control - 0 g L-1, 2.5 g L-1, 5.0 g L-1, 7.5 g L-1 and 10.0 g L-1. The plants were grown in a greenhouse under drip irrigation. The shoot length, length of the largest inflorescence, number of stems, diameter of the largest stem, mean length of the stems, number of open flowers, fruits and senescent flowers, chlorophyll a, b and total, mass of dry matter of shoot and root system were evaluated after 286 days. The experimental design was completely randomized, with four replicates of six pots per plot. Data were submitted to analysis of variance (ANOVA) followed by polynomial regression by SigmaPlot 11.0. It was possible to adjust a quadratic equation for the variables: shoot length (with maximum response point in 7.2 g L-1), mean length of stems (6.7 g L-1), diameter of the largest stem and the root system (5.9 g L-1), number of open flowers, buds, senescent flowers and total flowers (7.7 g L-1). For the variables, number of stems, number of fruits, chlorophyll a, b and total did not differ between treatments. The slow releaser fertilizer indicated dose for the cultivation of the potted species is 7.2 g L-1.

Effect of Glyphosate on Guineagrass Submitted to Different Soil Water Potential

ABSTRACT: The action of herbicides on weeds that develop under water deficit can be compromised, because the routes of penetration of hydrophilic herbicides are reduced due to the lower hydration of the cuticle in these plants. Moreover, hydrophobic compounds found in the epicuticular wax coating of plants under water stress, hinder the penetration of hydrophilic compounds. This study evaluated the control efficiency of glyphosate on guineagrass plants when submitted to different water deficits. The study was conducted in a greenhouse, and treatments were composed of guineagrass plants submitted to three soil water conditions [low water deficit (13%), intermediate water deficit (10%) and high water restriction (8%)], three doses of glyphosate (0.0, 270.0 and 540.0 g ha-1) and two phenological stages of plant development (4-6 leaves and 1-3 tillers). The water management started when plants presented two developed leaves. Visual evaluations were performed 7, 14, 21 and 35 days after the application of the herbicide; the morpho-physiological parameters of the specific leaf area, stomatal conductance and the difference between the environment temperature and the leaf temperature on the day of the herbicide application were also analyzed at the end of the study, as well as the dry matter of shoot and root. With the increase of the water restriction, there was a decrease in the analyzed morpho-physiological parameters, as well as in the dry matter accumulation of the shoot and roots of the studied plants. Plant control was more efficient when a 540 g ha-1 dose of glyphosate was applied, and when they were controlled at their vegetative stage of 1-3 tiller, and with a water management of 13%. It is possible to state that guineagrass under water restriction have less control efficacy when treated with glyphosate.

SUPERAÇÃO DA DORMÊNCIA DE SEMENTES DE <i>Sapindus saponaria</i> L.

Sapindus saponaria L. (Sapindaceae) é uma espécie nativa do Brasil utilizada na recuperação de áreas degradadas e detém propriedades medicinais, mas a dormência das suas sementes dificulta a germinação e a obtenção de plântulas de forma rápida. O presente estudo teve por objetivo avaliar a eficiência de diferentes métodos na superação da dormência de sementes de Sapindus saponaria. Os tratamentos para a superação da dormência das sementes foram: testemunha - sementes intactas; imersão em ácido sulfúrico concentrado (H2SO4 96% P.A) por 60, 70, 80 e 90 minutos; imersão em ácido sulfúrico concentrado por 60, 70, 80 e 90 minutos seguido de embebição em água destilada à temperatura ambiente por 12, 24 e 36 horas; imersão em água a 70°C por 10 e 15 minutos seguida de exposição em geladeira (6°C) por 30 minutos; imersão em água a 70°C por 10 e 15 minutos seguida de exposição em freezer (-18°C) por 30 minutos; choque térmico mediante a exposição das sementes em estufa de circulação forçada de ar regulada a 70°C por 5, 10 e 15 minutos seguida de transferência para geladeira e freezer durante 30 minutos. Para fins de comparação entre os tratamentos foram avaliados a porcentagem de emergência, velocidade e primeira contagem de emergência, comprimento de parte aérea e raiz primária, massa seca de parte aérea e raízes. A imersão das sementes em ácido sulfúrico por 80 minutos seguida de embebição em água por 24 horas é eficiente para superar a dormência, acelerar e promover a emergência e crescimento das plântulas de Sapindus saponaria.

Earthworms and Fusarium oxysporum: effect on strawberry plant growth and production

Earthworms are soil invertebrates that play an important environmental role and are often referred to as “ecosystem engineers”. These invertebrates can influence several organisms, from microscopic life forms to plants. Although many works had reported positive effects of earthworms on plant growth, studies combining these invertebrates and soil pathogens showed numerous positive interactions. Fusarium wilt is a global disease that can cause severe damage to strawberry fields. The aim of this study was to evaluate the effects of inoculation of earthworms (Lumbricus terrestris) and Fusarium wilt (Fusarium oxysporum f. sp. fragariae) in strawberry plants. This greenhouse experiment was carried out in the University of Seville School of Agricultural Engineering, Utrera City, Spain. Strawberries (Rooted cuttings) were planted in plastic pots and administered the following treatments: Control (absence of F. oxysporum f. sp. fragariae and earthworms), T1 (absence of F. oxysporum f. sp. fragariae, two L. terrestris per pot), T2 (inoculum of F. oxysporum f. sp. fragariae, absence of L. terrestris), and T3 (inoculum of F. oxysporum f. sp. fragariae and two L. terrestris). Weekly fruit production was measured for seven months. After this period the shoot fresh weight and the leaf nutrient content was measured. The results obtained showed no interaction between L. terrestris and F. oxysporum f. sp. fragariae on strawberry production. T1 treatment resulted in fruit production superior to other treatments, including the control. An absence of differences in dry shoot matter was observed with earthworm treatment, and small differences were found in the leaf nutrient content. The earthworm inoculation was unable to suppress the negative effects of Fusarium wilt in strawberry production. However, positive effects such as a reduction in the disease severity were found in the earthworm treated plants. In treatments without F. oxysporum f. sp. fragariae inoculation, the presence of earthworms increased plant productivity by 44.21 g per pot, compared with the control.

Tripartite Relationships in Legume Crops Are Plant-Microorganism-Specific and Strongly Influenced by Salinity

This study investigated the effects of specific strains of two arbuscular mycorrhizae fungi (AMF) (Rhizophagus irregularis and Claroideoglomus claroideum) and of two plant growth-promoting bacteria (PGPB) (Rhizobium leguminosarum and Burkholderia spp.), supplied either individually or as combination of a mixture of both arbuscular mycorrhizae fungi with each bacteria on root morphology, growth and fresh grain yield in pea (Pisum sativum L.) plants. Inoculated and non-inoculated pea plants were subjected to two levels of salinity (0 and 50 mM) by the addition of sodium chloride into tap water. Prior to fresh grain harvesting the morphology of root system was analyzed and the dry matter of roots and shoots were individually measured in randomly selected plants. Fresh pods were individually harvested per each plant; fresh (green) grains were separately counted and weighted per each pod at each individual plant, and the average grain weight was calculated by dividing total grain weight of plant with the respective number of green grains. The raise of salinity in the irrigation water strongly diminished the growth of pea plants by significantly reducing weight, length, surface area and root volume of pea plants. The relationships of pea plants with beneficiary fungi and bacteria were specific to each microorganism and highly depended on the environment. We found that under saline conditions, Rhizophagus irregularis provided a better vegetative growth and a higher yield than Claroideoglomus claroideum. Although, single application of Burkolderia spp. provides a better vegetative growth than single application of Rhizobium leguminosarum the best results, in terms of growth and harvested yield, were still obtained by combined application of AM fungi with Rhizobium leguminosarum. This combination was able to sustain the average grain weight at the level of non-saline plants and provided a significantly higher yield than the control plants.

RESÍDUO AGROINDUSTRIAL E LODO DE ESGOTO COMO SUBSTRATO PARA A PRODUÇÃO DE MUDAS DE <i>Eucalyptus urograndis</i>

Os objetivos desse trabalho foram avaliar o uso de substratos à base de resíduos da agroindústria do palmito e lodo de esgoto compostados, na produção de mudas de Eucalyptus urograndis, com diferentes níveis de fertilizante, e compará-los a um substrato comercial. Foram utilizados 3 substratos à base de lodo de esgoto e casca de pupunha nas proporções: 50/50; 33/66 e 25/75 v:v, quatro doses de fertilizante granulado (0; 2,0; 4,0 e 6,0 g dm-3) e um substrato comercial. Foram avaliados o diâmetro de colo, altura das plantas, H/D, matéria seca da parte aérea e raiz e qualidade do torrão. O uso de lodo de esgoto e casca de pupunha tem viabilidade como substrato na produção de mudas de Eucalyptus urograndis, com desempenhos iguais ou superiores ao substrato comercial. O aumento das doses do fertilizante granulado proporcionou efeitos significativos na qualidade das mudas, sendo recomendado o uso de doses acima de 4,0 g dm-3.

Substrate and seed sowing position on the production of Plukenetia volubilis L. seedlings

ABSTRACT Plukenetia volubilis is a species native to the Amazonia and has economic potential due to the high contents of polyunsaturated fatty acids and vitamins of the seeds; however, information about production of seedlings in nursery is scarce. Factors that contribute to fast emergence and generation of vigorous seedlings are desirable for plant production in the nursery. Therefore, this study aimed to identify the most favorable substrate and seed position for the production of P. volubilis seedlings. The seeds were sown in the following four positions: hilum facing up, hilum facing down, seed lying on its cotyledon suture, and seed lying flat on one of its cotyledon faces. The substrates were sand, vermiculite and commercial substrate. Treatments were distributed according to a completely randomized design in a 4 × 3 factorial arrangement (seed position and substrate) with three replicates of 25 seeds each. The following variables were evaluated: emergence percentage; first count of seedlings; number, width and length of leaves; plant height; stem diameter; dry matter of shoots and roots. It was concluded that the production of P. volubilis seedlings is not affected by either substrate or seed position at sowing. The substrates most favorable to the quality of P. volubilis seedlings were the commercial substrate and vermiculite, always for the positions of seed lying on its cotyledon suture, with faces parallel to tube walls, and seed lying flat on one of its faces.

Regional Substrates of the Brazilian Northeast on Acclimatization and Development Morphological of Minirose

The transition from heterotrophism to autotrophism in acclimatization is a delicate process for most species. The objective of this work was to evaluate combinations of regional substrates of the Brazilian Northeast in the acclimatization and morphological development of minirose (Rosa chinensis ‘Minima’) seedlings. The experiment was carried out in a greenhouse using seedlings with 30 days of in vitro culture. The treatments were constituted by: 1) dry coconut powder; 2) 75% dry coconut powder + 25% rice husk; 3) 50% dry coconut powder + 50% rice husk; 4) 75% dry coconut powder + 25% charcoal rice husk; 5) 50% dry coconut powder + 50% carbonized rice husk; 6) 100% vermiculite; 7) 50% vermiculite + 50% dry coconut powder; 8) commercial substrate; 9) 75% sand + 25% dry coconut powder and 10) 50% sand + 50% dry coconut powder. After 21 days, the following characteristics were evaluated: survival percentage, leaf number, shoot height, dry matter of shoot and root and total dry matter. The regional materials tested showed a good choice of substrates to be used in the acclimatization of minirose seedlings. The vermiculite presented the worst results in the characteristics evaluated. Dry coconut powder as substrate should be used in mixtures with other materials to provide better acclimatization conditions. The use of 50% dry coconut powder + 50% rice husk provided a best development and growth of minirose seedlings (Rosa chinensis ‘Minima’) than other tested substrates

Hydropriming as inducer of salinity tolerance in sunflower seeds

ABSTRACT Sunflower is a species with multiple potentialities and its yield can be affected by the presence of soluble salts in the soil, which is common in arid, semi-arid and irrigated regions. The objective of this study was to evaluate the effect of hydropriming as inducer of salinity tolerance in seeds and seedlings of sunflower, hybrid MG305CP. The germination tests were set with four replicates of 50 seeds per treatment, maintained in germinator at 30 ºC for ten days. To simulate salinity, sodium chloride diluted in distilled water was used at electrical conductivities of 0 (control), 4, 8, 12 and 16 dS m-1. On the tenth day, the number of normal seedlings was counted and the length and dry matter of shoots and roots were determined. Seedling fresh matter was used to determine the contents of total chlorophyll, total soluble sugars and proline. The experimental design was completely randomized, in a 2 x 5 factorial scheme (with and without hydropriming and five levels of salinity). Hydroprimed sunflower seeds showed greater vigor expression, with higher number of normal seedlings and faster germination.

Crescimento inicial de cana-de-açúcar inoculada com fungos micorrízicos arbusculares e fósforo

The objective of this study was to evaluate the effect of inoculation with different arbuscular mycorrhizal fungi (AMF) species and P levels (KH2PO4) on growth and nitrogen (N) and P contents in plants of sugarcane. The experiment was conducted in a greenhouse using a completely randomized design in a factorial 6×5+1, with 4 replicates, the factors being evaluated: levels of P (0, 50, 100, 200, 400 and 800 mg kg-1), inoculation with AMF (Claroideoglomus etunicatum, Gigaspora albida, Gigaspora margarita, Rhizophagus clarus and indigenous AMF in the area of sugarcane cultivation) and a control without inoculation. At 60 and 90 days after planting at a level 50 mg kg-1 of P plants inoculated with G. albida had greater height. Plants inoculated with G. albida, in level 0 mg kg-1 of P, had 300 % increase in shoot dry matter compared to the absence of inoculation. The maximum production of dry matter of shoots of plants inoculated with G. albida was 149 g associated with 424 mg kg-1 of P. The inoculation with G. albida favors the initial growth and N content of the sugarcane plants, whose dependence and mycorrhizal efficiency was 13.6% and 254%, respectively, at the dose 0 mg kg-1 of P.

Silicon affects seed development and leaf macrohair formation in Brachypodium distachyon.

Silicon (Si) has many beneficial effects in plants, especially for the survival from biotic and abiotic stresses. However, Si may negatively affect the quality of lignocellulosic biomass for bioenergy purposes. Despite many studies, the regulation of Si distribution and deposition in plants remains to be fully understood. Here, we have identified the Brachypodium distachyon mutant low-silicon 1 (Bdlsi1-1), with impaired channeling function of the Si influx transporter BdLSI1, resulting in a substantial reduction of Si in shoots. Bioimaging by laser ablation-inductively coupled plasma-mass spectrometry showed that the wild-type plants deposited Si mainly in the bracts, awns and leaf macrohairs. The Bdlsi1-1 mutants showed substantial (>90%) reduction of Si in the mature shoots. The Bdlsi1-1 leaves had fewer, shorter macrohairs, but the overall pattern of Si distribution in bracts and leaf tissues was similar to that in the wild-type. The Bdlsi1-1 plants supplied with Si had significantly lower seed weights, compared to the wild-type. In low-Si media, the seed weight of wild-type plants was similar to that of Bdlsi1-1 mutants supplied with Si, while the Bdlsi1-1 seed weight decreased further. We conclude that Si deficiency results in widespread alterations in leaf surface morphology and seed formation in Brachypodium, showing the importance of Si for successful development in grasses.

Initial Growth of Eremanthus incanus (Less.) Less in Soil with Manganese

ABSTRACT The objective of this study was to evaluate the initial growth of Eremanthus incanus (Less.) Less (candeia) in soil with manganese doses. Additionally, it sought to assess manganese concentration, and accumulation in the organs of the plant as well as quantify the appropriate concentration of this element in the soil. The experiment was installed in a greenhouse and used manganese doses of 0, 50, 150 and 450 mg kg-1 soil. The experimental design used randomized blocks with five replications. Stem diameter and plant height; dry matter of root, shoot and total, and concentration and accumulation of manganese in the leaf, stem and root were evaluated. The manganese concentration in the soil was quantified using the Mehlich-1 and DTPA pH 7.3 extractors. A reduction in growth and high manganese concentrations in all parts of the plant were observed. For Melich-1 extraction the appropriate manganese concentration is 15.90 mg kg-1 and for DTPA it is 3.02 mg kg-1. The use of the candeia for phytoremediation is not recommended due to sensitivity to manganese.