RESPONSIVIDADE DE PLANTAS DE MILHO À INOCULAÇÃO COM FUNGOS MICORRÍZICOS ARBUSCULARES DA RIZOSFERA DE IPÊ AMARELO

ABSTRACT: Increasing corn productivity in a sustainable manner is the challenge of all farmers, and thus the objective was to isolate and select arbuscular mycorrhizal fungi (AMF) native to the rhizosphere of ipê amarelo (Tabebuia serratifolia (Vahl) Nichols) and to evaluate the effect of their inoculation in corn plants. The AMF extraction from the rhizosphere of ipê amarelo, the isolation and inoculation of the spores in corn plants were carried out in the Laboratory of Vegetal Fisiology and Growth of Plants of the Universidade Federal do Oeste do Pará (UFOPA) in Octuber 2017. The effect of symbiosis on initial plant growth was evaluated under laboratory conditions, under artificial lighting with photoperiod of 12 hours and daily watering for 15 days. 410 spores of AMF belonging to three species, Glomus clarum, G etunicatum and G. geosporum were isolated. AMF efficiently colonized the root system of corn plants and provided, in the first collection, increments greater than 100% in root dry mass and aerial parts, when compared to control plants. It is concluded that the inoculation with AMF, native to the rhizosphere of ipê amarelo, increases the dry mass of the plants, becoming a promising inoculant for corn cultivation.KEYWORD: Mycorrhizae, Productivity, Vegetative growth.El aumento de la productividad del maíz de una forma sostenible es el desafío de todos los agricultores, se ha objetivado aislar y seleccionar hongos micorrizas arbusculares (HMA) nativos de la rizosfera de ipê amarillo (Tabebuia serratifolia (Vahl) Nichols) y evaluar el efecto de su inoculación en las plantas de maíz. La extracción de los HMA de la rizosfera de ipê amarillo, el aislamiento y la inoculación de las esporas en plantas de maíz se realizaron en el Laboratorio de Fisiologia Vegetal e Crescimento de Plantas de la Universidade Federal do Oeste de Pará (UFOPA) en octubre de 2017. El efecto de la simbiosis en el crecimiento inicial de las plantas fue evaluado en condiciones de laboratorio, bajo iluminación artificial con fotoperíodo de 12 horas y riegos diarios por 15 días.Se aislaron 410 esporas de HMA pertenecientes a tres especies: Glomus clarum, G etunicatum y G. geosporum.Los HMA colonizaron de forma eficiente el sistema radicular de las plantas de maíz y proporcionaron, en la primera colecta, incrementos superiores al 100% en la masa seca de la raíz y de la parte aérea, cuando comparadas a las plantas control. Se concluye que la inoculación con los HMA, nativos de la rizosfera del ipê amarelo, aumenta la masa seca de las plantas, convirtiéndose, en un inoculante prometedor para el cultivo del maíz.PALABRA CLAVE: Crecimiento vegetativo, Micorrizas, Productividad.Aumentar a produtividade do milho de uma forma sustentável é o desafio de todos os agricultores, objetivou-se isolar e selecionar fungos micorrizicos arbusculares (FMAs) nativos da rizosfera de ipê amarelo (Tabebuia serratifolia (Vahl) Nichols) e avaliar o efeito de sua inoculação em plantas de milho. A extração dos FMAs da rizosfera de ipê amarelo, o isolamento e a inoculação dos esporos em plantas de milho foram realizados no Laboratório de Fisiologia Vegetal e Crescimento de Plantas da Universidade Federal do Oeste do Pará (UFOPA) em outubro de 2017. O efeito da simbiose no crescimento inicial das plantas foi avaliado em condições de laboratório, sob iluminação artificial com fotoperíodo de 12 horas e regas diárias por 15 dias. Foram isolados 410 esporos de FMAs pertencentes a três espécies: Glomus clarum, G etunicatum e G. geosporum. Os FMAs colonizaram de forma eficiente o sistema radicular das plantas de milho e proporcionaram, na primeira coleta, incrementos superiores a 100% na massa seca da raiz e da parte aérea, quando comparadas às plantas controle. Conclui-se que a inoculação com os FMAs, nativos da rizosfera do ipê amarelo, aumenta a massa seca das plantas, tornando-se, um inoculante promissor para o cultivo do milho.PALAVRA CHAVE: Crescimento vegetativo, Micorrizas, Produtividade

Arbuscular Mycorrhizal Fungi Promote Physiological and Biochemical Advantages in Handroanthus serratifolius Seedlings Submitted to Different Water Deficits

Climate change causes increasingly longer periods of drought, often causing the death of plants, especially when they are in the early stages of development. Studying the benefits provided by arbuscular mycorrhizal (AM) fungi to plants in different water regimes is an efficient and sustainable strategy to face climate change. Thus, this study investigated the influence of AM fungi on Handroanthus serratifolius seedlings under different water regimes, based on biochemical, and nutritional growth parameters. The experiment was carried out in H. serratifolius seedlings cultivated with mycorrhizas (+AMF) and without mycorrhizas (-AMF) in three water regimes; a severe water deficit (SD), a moderate water deficit (MD), and a well-watered (WW) condition. AM fungi provided greater osmoregulation under water deficit conditions through the accumulation of soluble sugars, total free amino acids, and proline, as well as by reducing sugar. The increase in the absorption of phosphorus and nitrate was observed only in the presence of fungi in the well-watered regimen. A higher percentage of colonization was found in plants submitted to the well-watered regimen. Ultimately, AM fungi promoted biochemical, nutritional, and growth benefits for H. serratifolius seedlings under the water deficit and well-hydrated conditions, proving that AMF can be used to increase the tolerance of H. serratifolius plants, and help them to survive climate change

<b>Morphological characterization of fruits, diaspores and germination of <i>Miconia ligustroides</i> (DC.) Naundim (Melastomataceae)</b> - doi: 10.4025/actascibiolsci.v35i1.12648

<p class="aresumo"><em>Miconia ligustroides</em> (DC.) Naudim, popularly known as “vassoura-preta” or “jacatirão-do-brejo” is widely distributed in Brazil. It is a recommended species for restoration of riparian areas and its fruits are attractive to wildlife. However, little is known about the morphology of its fruits and diaspores. Such morphological characterization studies are important for species identification, corroborating future studies of phenology and germination. Therefore, the fruits, diaspores and germination of <em>M. ligustroides</em> were morphologically characterized by observations through naked eye, stereoscopic microscopy and scanning electron microscopy. Analyses of chemical composition of seeds were also performed. The fruits are spherical and uniform within the analyzed sample, having a large number of tiny obtriangular yellowish-brown diaspores. The diaspores are considered ananfitropos, and have crystals in their external envelope. Concerning chemical composition, they are proteins. Germination is of phanerocotylar type and starts at 12 Days After Sowing (DAS); at 17 DAS each diaspore may produce up to three seedlings. The morphological characterization performed in this work was efficient to describe the fruits, seeds and germination of this species, thus providing the basis for future studies.</p> <p class="apalavrachave"> </p

Resistance Mechanisms of Peltophorum dubium (Sprengel) Taubert Submitted to Flood Conditions

ABSTRACT Peltophorum dubium (Sprengel) Taubert seedlings were submitted to 60 days of flooding, with and without Ca+. During this period, growth, root anatomy and chlorophyll content were analyzed. The relative growth rates (RGR) of roots and shoots were higher in non-flooded plants. The flooded treatments, with and without Ca+, have affected the roots growth but did not affect the shoot and the stem diameter. The anatomy analysis showed thickening of the sclerenchyma in 15 and 60 days in the flooded treatments with and without Ca+, and the vessel diameter was smaller at 45 days. The chlorophyll content differed, however it was not statistically significant. The results indicate that Peltophorum dubium as candidate specie for reforestation in areas subjected to continuous flooding for up to 60 days, since no mortality was observed

Prevalence of supranumerary teeth on pre-molars region and their association with third molars

O objetivo do presente estudo foi determinar a prevalência de supranumerários na região dos pré-molares nos estágios de dentadura decídua, mista e permanente, além de verificar sua associação com a presença de terceiros molares. Foram avaliadas radiografias panorâmicas de 1.976 pacientes matriculados no curso de Ortodontia Preventiva e Interceptiva da Profis (Sociedade de Promoção Social do Fissurado Lábio-Palatal), em Bauru-SP. As radiografias foram analisadas em negatoscópio, em ambiente escurecido, por um único examinador que determinou a presença de supranumerários na região dos pré-molares, bem como a presença de terceiros molares. A associação entre o aparecimento de supranumerários e a presença de terceiros molares foi verificada pelo Teste de McNemar. O Teste exato de Fisher foi aplicado para verificar o dimorfismo sexual. Constatou-se uma prevalência de 0,45% de supranumerários na região dos pré-molares na amostra estudada, sendo 11% na maxila e 89% na mandíbula, e não foi observado dimorfismo sexual em relação ao aparecimento dos supranumerários (p=0,32). Nas radiografias avaliadas, foi observado que os quatro terceiros molares estavam presentes sempre que verificada a presença dos supranumerários, detectando uma associação estatisticamente significante (p < 0,01) entre o aparecimento dos pré-molares supranumerários e a presença dos terceiros molares. Concluiu-se que a incidência de pré-molares supranumerários foi baixa na população estudada, e que existe associação entre o aparecimento destes supranumerários com a presença dos terceiros molares.The purpose of the present study was to determine the prevalence of supranumerary teeth on the pre-molar region during the deciduous, mixed and permanent dentition and also verify their association with the presence of third molars. 1.976 panoramic radiographic from patients of the Preventive and Interceptive Orthodontic Course from Profis (Sociedade de Promoção Social do Fissurado Lábio-Palatal), in Bauru-SP were evaluated the radiographies were analysed in viewing box in a dark room by one unique examiner who determined the presence of supranumerary teeth on pre-molars region and also the presence of third molars. The association between the supranumerary and the third molars was verified by the McNemar test. The Fischer's exact test was used to verify the sexual dimorphism. A prevalence of 0,45% of supranumerary teeth on the pre-molars region was found on the sample, 11% on the maxilla and 89% on the mandible. No sexual dimorphism was found (p=0,32). A statistically significant difference (p<0,01) association between supranumerary pre-molars and the presence of third molar was found. The conclusion is that the incidence of supranumerary pre-molar is low on the examined sample and there is an association between the supranumerary pre-molars and the presence of third molars

Agronomic biofortification of waterleaf (Talinum triangulare) with zinc applied via root

Abstract Zinc (Zn) deficiency affects one-third of the world’s population, and agronomic biofortification is a good way to fight against this problem. Biofortification of leafy vegetables has been driven by their consumption, and, in this scenario, the waterleaf (Talinum triangulare) demonstrates good potential. Thus, this work aimed to verify the efficiency of agronomic biofortification of waterleaf with Zn applied via root. For the experiment, seedlings obtained with vegetative propagation by cuttings were used and cultivated in a mixture of sand and commercial substrate, initially in the laboratory. After acclimatization, the seedlings were transferred to a plant nursery, where NPK and Zn were applied, in six treatments (source Zinc Sulphate Heptahydrate, ZnSO4.7H2O), T1: control; T2: 12.5 mg kg-1; T3: 25 mg kg-1; T4: 50 mg kg-1; T5: 100 mg kg-1; T6: 400 mg kg-1. The length, number of leaves, shoots, inflorescences, and diameter of the collection were measured. The leaf dry mass (LDM), stem (SDM), root (RDM), root-shoot ratio (R S-1), leaf weight ratio (LWR), Dickson’s Quality Index (DQI), leaf and soil Zn levels, total proteins and soluble sugars (TSS) were analyzed. The dose of 400 mg kg-1 provided toxicity to plants, and the dose of 100 mg kg-1 demonstrated better results in plant growth and development and contents of proteins and zinc, with an increase of 4081% of Zn, indicating which is the most effective dose to be used in the biofortification of this species

Selenium Application Provides Nutritional and Metabolic Benefits to Wheat Plants

Selenium is beneficial to plants and is essential for animals and humans, which justifies any efforts for producing Se-enriched wheat grains worldwide. This study aimed to (i) verify if wheat is an efficient species to be used for Se biofortification in tropical agroecosystems and (ii) assess the influence of Se on the physiological and biochemical parameters of wheat plants. Selenium was applied as sodium selenate (Na2SeO4) at different doses (12, 21, 38, 68, and 120 g ha−1) in soil. The dose of 120 g ha−1 of Se resulted in Se contents of 7.98 and 2.27 mg kg−1 in the leaves and grains, respectively. The supply of 38 g ha−1 of Se increased the total soluble sugar content by 50%, with reducing sugars increasing by 17% and sucrose augmenting 53%, compared with that in the control. The doses of 12, 68, and 120 g of Se ha−1 promoted a significant increase in catalase activity. In addition, Se application increased carbohydrate and nutrient contents. Our findings indicate that wheat is a good species for agronomic biofortification with Se via soil application in tropical agroecosystems. Selenium proved to be a valuable element for plants since it provides physiological and biochemical benefits