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This study aimed to evaluate the biometric characteristics of fruits and seeds of Diospyros inconstans Jacq., germination and formation of seedlings obtained from fruits at three maturity stages, subjected to different temperatures. Biometric data were obtained from 100 fruits and 100 seeds. The determining parameters in the biometry of the fruits were: length, width, mass and number of seeds/fruit and for the seeds: length, width, thickness and mass. In the germination test, a factorial scheme (3x4), three maturity stages (green, intermediate and reddish), and four temperatures (20, 25, 30 and 35 °C) were used. The analyzed variables were: germination, germination speed index (GSI), mean germination time (MGT), time to obtain 50% germination (t50), percentage of seedlings, length and dry mass of shoots and roots, and collar diameter. Fruits and seeds showed greater variation in the parameters fresh mass and number of seeds per fruit. The germination speed index was higher in seeds from reddish fruits, and seeds from green fruits originated betterdeveloped seedlings. Temperatures of 25 and 30 °C are recommended for conducting the seed germination test at the three maturity stages. [ABSTRACT FROM AUTHOR]

A comparative study for evaluating the influence of metal oxide nanoparticles (MONPs) (Al2O3, TiO2, and SiO2) on seed germination and seedling growth in okra was implemented under water deficit stress stimulated by PEG-6000. The results revealed that additive of SiO2 nanoparticles (SNPs) and Al2O3 (ANPs) have significant positive effect on seeds germination, while a reduction of that were observed by using TiO2 nanoparticles (TNPs) at 50 mg.L-1 concentration under 5% PEG-6000 stimulated drought stress as compared to that without MONPs. Further, relative to non-MONPs treatment, all the tested MONPs dramatically enhanced the drought stress tolerance in okra seedlings due to the improvement of morphological growth despite a few traits were inhibited under certain water deficiency to some degree. Improvement of drought resistance induced by TNPs and ANPs were found to be higher than that by SNPs. Our finding provides a promising approach to cope with water scarcity, as application of metal oxide nanoparticles to be a potential option to protect okra plants against drought stress. [ABSTRACT FROM AUTHOR]

The optimal combination between sowing density and nitrogen (N) fertilization rate is a challenge for the production of high-quality seeds, considering the diversity of genotypes and environments. This study aimed to evaluate the yield and physiological quality of wheat seeds as a function of sowing density and N rate, under different edaphoclimatic conditions. The experiment was carried out in three environments (Londrina, Cascavel, and Ponta Grossa) in a randomized block design with four replications, considering a 2 × 3 × 4 factorial arrangement composed of two genotypes (BRS Anambé and WT 15-025), three sowing densities (250, 350, and 450 seeds.m-2), and four N rates (0, 40, 80, and 120 kg.ha-1). The following seed features were evaluated: yield, first germination count, final seed germination, seedling emergence, emergence speed index, seedling length, and seedling dry matter. Seed yield varied as a function of environment and genotype. BRS Anambé produced seeds with higher physiological quality. The optimal combination between sowing density and N rate that provided the more suitable economic yield, without affecting the physiological quality of wheat seeds, varied with the environment and was estimated in 250 seeds.m-2 × 0 kg.ha-1 N for Londrina and Cascavel, and 350 seeds.m-2 × 18 kg.ha-1 N for Ponta Grossa. [ABSTRACT FROM AUTHOR]

This may be attributed to the facts that nanotechnology has shown an excellent ability to control the release pattern of active ingredients of pesticides, so that it can achieve long-term functions more effectively, thus overcoming the problems of agricultural runoff and residual pesticide accumulation. In addition, Nanopesticides have shown greater solubility and stability of active ingredients, which can effectively control pests (Akhtar et al.,2020). In this study, the insecticidal relative toxicity of carbon nanotubes (CNTs) synthesized from seeds of Iraqi date palm Phoenix dactylifera L. using a chemical vapor deposition (CVD) method was investigated. These Nanoparticles were evaluated against adult and larvae of the Khapra beetle, Trogoderma granarium. The results indicated that CNTs (25, 50 and 100 ppm) caused mortality of the Khapra beetle under laboratory conditions. Additionally, the germination percentage of wheat, Triticum aestivum L. grains, has not been affected by the carbon nanotube treatments at 25-100 ppm. This study demonstrates the potential of CNTs as a technology for population control of T. granarium because of their toxicity to larvae and adults. [ABSTRACT FROM AUTHOR]

Background: Productivity is increased with breeding techniques and modes for obtaining highly productive cultivars, various agricultural activities, and the use of new technologies for growing planting material. Some of modes to increase productivity are simple. They use different growth stimulants. Many methods were developed to synthesize organic compounds that have stimulating biological activity and can be used as growth stimulants for agricultural crop. Aim: The purpose of this research was to study the effect of synthesized organic compounds of the general formula: 1-alkyl-2,2,4-trimethyl-6-aminocarbothioyl-1,2- dihydroquinoline and 1-alkyl-2,2,4-trimethyl-6-aminocarbothioyl-1,2,3,4-tetrahydroquinoline on growth indicators (by which we meant seed germination and plant height, length, width, and the number of leaves) and the yield of the agricultural crop. Methods: To identify the biological effects of the synthesized organic compounds, morphometric parameters of an annual vegetable crop (Solanum melongena L.) were selected. It is investigated seed germination, growth processes, and yield. Growth processes were studied by biometric indicators. Biometric indicators included the plant height, length, width, and the number of leaves. Results and Discussion: The most effective growth stimulators from compounds of the series 1-alkyl-2,2,4-trimethyl-6- aminocarbothioyl-1,2-dihydroquinoline and 1-alkyl-2,2,4-trimethyl-6-aminocarbothioyl-1,2,3,4- tetrahydroquinoline for common eggplant were revealed. The most effective substances for Solanum melongena are 1,2,2,4-tetramethyl-6-(1-piperidinylcarbothioyl)-1,2,3,4-tetrahydroquinoline hydrochloride and 4- [(1,2,2,4-tetramethyl-1,2-dihydro-6-quinolinyl)carbothioyl]-1-piperazinylcarbaldehyde hydrochloride in tested concentrations (0,01 %; 0,05 % and 0,1 %), as well as the compounds of the general formula: 1-alkyl-2,2,4- trimethyl-6-aminocarbothioyl-1,2,3,4-tetrahydroquinoline in concentrations of 0,05 % and 0,1 %. It was established that the synthesized chemical substances cause stimulation of the eggplant growth compared with existing commercial preparation. Compounds of the series 1-alkyl-2,2,4-trimethyl-6-aminocarbothioyl-1,2- dihydroquinoline and 1-alkyl-2,2,4-trimethyl-6-aminocarbothioil-1,2,3,4-tetrahydroquinoline increase the seed germination of Solanum melongena from 30 to 80 %, the vegetative mass - from 10 to 40 %, yield - from 28 to 46 %. Conclusions: Tetrahydroquinolines are most effective as stimulants of growth processes (and productivity) for common eggplant. Compounds containing a dihydro-6-quinolinyl substituent stimulate the growth and also increase the yield of Solanum melongena. The expediency of quinoline series compounds for the production of vegetable growing is shown. Used growth stimulators increase the adaptive potential of Solanum melongena. [ABSTRACT FROM AUTHOR]

Contextualization: Lupinus bracteolaris is a heliophile species that vegetates lowlands, open slopes and sandstone hills. Knowledge gap: Despite this great rusticity, there is little information about the species and its propagation, especially regarding the germination of its seeds. Purpose: Evaluate the seeds of Lupinus bracteolaris, through pre-germinative treatments, substrate, temperature, luminosity, and water absorption, to understand the initial germination processes of the species. Methodology: Fruits were collected from 20 matrix plants, then the seeds were processed and submitted to the following tests: Pregerminative methods (six treatments at 25 °C; substrates and temperatures (sand and paper at 20, 25 and 30 °C); photoblast test (white light, diffuse-green light and continuous dark under 20 °C) and the imbibition curve (control and scarification between sandpaper under 20 °C). Evaluations: Percentage of germination and formed seedlings, germination speed index, average germination time and seedling formation, using a completely randomized design. Results and conclusions: The results of the analyzed variables showed relevance for the pre-germinative treatment between sandpapers for 20 seconds, in addition, the substrate paper Germibox and the temperature of 20 °C were the most suitable during the germination of the seeds of Lupinus bracteolaris, which were classified as neutral photoblastics and without dormancy. [ABSTRACT FROM AUTHOR]

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Este trabalho teve por objetivo analisar a germinação de sementes de Senegalia polyphylla (DC.) Britton & Rose (Fabaceae) atacadas por bruquíneos (Coleoptera: Chrysomelidae: Bruchinae). Frutos dessa espécie foram coletados em São Gonçalo do Rio Preto, MG. As sementes indenes e as danificadas por bruquíneos foram submetidas aos testes de germinação em cinco tratamentos, com 100 sementes cada. O melhor percentual de germinação foi obtido nas sementes sadias e lixadas. As sementes sadias embebidas em água apresentaram baixo percentual de germinação. O ataque de bruquíneos proporcionou redução na taxa de germinação, mas não impediu que esse processo ocorresse nas sementes danificadas.

RESUMO O pau-brasil, Paubrasilia echinata E.Gagnon, H.C.Lima & G.P.Lewis, é uma das mais importantes espécies vegetais do Brasil. Muitos fatores podem interferir na manutenção da viabilidade e na conservação das sementes, principalmente sua qualidade fisiológica inicial. Entre outros fatores, esta qualidade depende do grau de maturação, sendo importante identificar a maturidade fisiológica com vistas a determinar o melhor momento para a colheita das sementes. O presente trabalho descreve as modificações que ocorrem durante o processo de maturação das sementes de pau-brasil em três diferentes locais no Estado de São Paulo. Flores foram etiquetadas no dia de sua antese e os frutos foram colhidos diretamente dos ramos até os 65 dias após a antese (DAA). Os resultados sugerem que a maturidade fisiológica das sementes de pau-brasil ocorreu por volta de 60-65 DAA, imediatamente antes da deiscência da vagem, quando as sementes tinham 30-40% de água e quando há eficiente controle do fluxo de água entre sementes e frutos durante a maturação.

Garcinia brasiliensis is a tropical tree species of economic importance to local populations in the Amazon and Atlantic forests. The plant propagation of this species occurs mostly through seeds and despite that very little information about seedling emergence and growth is currently available. Here we assessed basic information on the seed and seedling ecophysiology of G. brasiliensis aiming at providing key details for seed propagation. Seeds are large and contain high levels of water when recently collected (c. 50%). Seed storage, especially under low temperature, resulted in very low seedling emergence. Fruit storage at c. 25 °C, on the other hand, was demonstrated to be the best option for maintaining seed viability in the short term. Removal of the seed coat considerably hastened and increased the percentage emergence of seedlings, despite the light condition. Similarly, a higher percentage and index of seedling emergence was observed under 35 °C over 25 °C, despite the substrate. Amongst all the substrates tested, sand resulted in lower seedling emergence. Cultivating seedlings in vermiculate and at 25 °C provided the best condition for root and shoot growth. Ideal conditions of light and temperature for seedling emergence and development mirror the environmental conditions under which plants of G. brasiliensis establish in nature. [ABSTRACT FROM AUTHOR]

Mimosa tenuiflora Willd., popularly known as jurema-preta, is an arboreal species of great importance for the brazilian Northeast due to its uses as a medicinal plant and in the restoration of degraded soils. No information is available in the Rules for Seed Analysis and the Instructions for Seed Analysis of Forest Species regarding ideal conditions for of this species. Thus, this study aimed at evaluating the influence of pre-germination treatments, in addition to verifying the germination performance at different temperatures and in different substrates. In both experiments, four replicates of 25 seeds were used for each treatment. In experiment I, seeds were submitted to the following methods for overcoming dormancy: witness - Intact seeds (T1) immersion in water at 100 °C for 1 (T2), 2 (T3), 3 (T4), 4 (T5), 5 (T6) and 6 min (T7), immersion in concentrated sulfuric acid for 1 (T8), 4 (T9), 7 (T10), 10 (T11) and 13 min (T12), scarification on sandpaper n° 80 (T13) and lopping in the region opposite the micropyle (T14). In experiment II, seed germination was evaluated in four types of substrates: between sand, paper on, paper roll and between vermiculite and at six different temperatures: 20, 25, 30, 35, 40 °C and alternating between 20 and 30 °C. Immersion in hot water for 1, 2, 3, 4, 5 and 6 min, sulfuric acid treatment for 10 and 13 min, sand paper and lopping were the most appropriate treatments to overcome seed dormancy. The seed germination of M. Tenuiflora should be carried out at 25 °C on paper roll substrate.

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Copyright of Journal of Exact Sciences is the property of Master Editora and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Passion fruits species presents a larger economic importance for in natura consumption and industry. The main way to propagate these species is by seeds; however, the aril presence and environmental conditions may inhibit the seeds germination. In this sense, the objective of this study was to evaluate the effect of aril removal methods and light conditions on P. edulis var. flavicarpa seeds quality and germination. There were used five methods to remove the seeds aril: (1) friction on steel mesh sieve for 5 minutes; (2) friction with coarse sand on steel mesh sieve for 5 minutes; (3) immersion in lime solution at 10% (w/v), for 30 minutes; (4) fermentation in sugar solution at 10% (w/v), during 48 hours; and (5) natural pulp fermentation, during five days. The seeds were submitted to germination test at darkness and lightness, as well as, to length seedlings and emergence test. Regardless the aril removal method, the germination percentage was lower at lightness than darkness highlighting the natural pulp fermentation treatment, which presented 86% of seeds germinated. On the other hand, the aril removal methods did not affect the seedlings emergence, with emergence percentages ranged from 88 to 94%.

Os objetivos neste estudo foram avaliar os efeitos da radiação γ sobre a sobrevivência e desenvolvimento de gemas de segmentos caulinares e germinação de sementes de maracujazeiro-amarelo (Passiflora edulis f. flavicarpa) in vitro. Os explantes de segmentos caulinares (2cm) contendo uma gema axilar, obtidos a partir de plântulas provenientes da germinação in vitro de sementes de maracujá, foram tratados com raios γ em dosagens variando de 10 a 60Gy e subsequentemente transferidos para meio Murashige e Skoog (MS), suplementado com 4,0mg L-1BAP. Para a irradiação das sementes, foram testadas doses que variaram de 75-200Gy e a germinação e sobrevivência das plântulas foram avaliadas após 30 e 60 dias da inoculação em meio MS, respectivamente. Após 30 dias da irradiação de segmentos caulinares, observou-se redução de 50% na sobrevivência dos explantes e no número de brotações formadas in vitro nas doses de 21,31 e 12,20Gy, respectivamente. A DL50 para a germinação de sementes é 160Gy, enquanto que, para sobrevivência das plântulas, é de 125Gy.

Avaliou-se a fitotoxicidade do extrato etanólico (CETOH), da fase orgânica (CEA) e do composto majoritário, o ácido (E)-cinâmico (AC), obtidos da polpa dos frutos da espécie popularmente conhecida como cujuba, cuieira e/ou cabaça (Crescentia cujete L.) sobre a inibição da germinação de sementes, desenvolvimento do hipocótilo e radícula das plantas invasoras Senna obtusifolia (L.) Irwin & Barneby (mata-pasto) e Mimosa pudica Mill. (malícia). A fase orgânica na concentração de 0,5% inibiu em 100% a germinação das sementes das duas plantas invasoras. O AC que foi obtido da fase orgânica inibiu a germinação das sementes de S. obtusifolia em 95% e de M. pudica em 99% na concentração de 0,1%, com concentração (%) tóxica para inibição de 50% (CI50) da germinação das sementes iguais a 0,063 e 0,037%, respectivamente; e nos bioensaios de crescimento de plântula, o AC foi mais eficiente sobre a radícula da planta S. obtusifolia (com CI50 igual a 0,009%) e para a planta M. pudica os valores de CI50 foram de 0,097% e 0,117% para a radícula e hipocótilo, respectivamente. Essa pesquisa reforça o potencial fitotóxico do ácido (E)-cinâmico, verificado inicialmente na fase orgânica em acetato de etila (CEA) rica nesse fenilpropanoide.

Guava (Psidium guajava L.) is a plant often employed in popular medicine. Recently several studies have alerted about the toxicity of substances present in medicinal plants, which can pose risks to the human health. In this sense, the present work aimed to investigate the phytotoxic, cytotoxic and genotoxic action of three guava varieties - Paluma, Pedro Sato and Roxa ("purple") - on the plant test system Lactuca sativa L. Thus, macro- and microscopic evaluations were carried out for five infusion concentrations (2.5, 5.0, 10.0, 20.0 and 40.0 g.L-1) prepared from each variety. Distilled water was used as negative control. Chromatographic and spectroscopic analysis by HPLC-PAD indicated that the chemical composition of the infusion of Roxa is different than that of the infusions of the varieties Paluma and Pedro Sato. It was observed that seed germination and root growth in L. sativa exposed to infusions decreased with increasing infusion concentration, regardless of the tested cultivar. For the mitotic index, no statistical differences were observed. On the other hand, a significant increase in the frequency of cell cycle alterations was verified, especially for the highest concentrations tested. The cytogenotoxic effect was significant. Therefore, guava should not be used indiscriminately in popular medicine.

The purpose of this study was to evaluate the chemical, physiological and genetic differences in seeds of cactus of the Cereus genus (mandacaru) cultivated in the Northeast (Picos, State of Piauí) and Southern (Maringá, State of Paraná) regions of Brazil. Over a period of eight days, temperatures of 25°C and 30°C were equally efficient for the germination of all the seeds. Oleic acid (C18:1) was the most common fatty acid found in the seeds collected in the Southern (41%) and Northeast (45.5%) regions. The analysis of lipases indicated that seeds from Maringá have high mean observed and expected heterozygosities and that seeds from Picos have a higher number of alleles per loci. Therefore, the seeds of mandacaru from the semiarid region of Northeast as well as the seeds from the South (the two contrasting regions of Brazil) are promising with regards to the preservation of the biodiversity in the genome of mandacaru. The low genetic identity between mandacaru seeds from Maringá and Picos at Lipase-5 locus analysis (I = 0.77) suggests that the mandacaru plants from Maringá and Picos may correspond to two species: C. peruvianus and C. jamacaru, respectively.

Copyright of Ciência Florestal (01039954) is the property of Ciencia Florestal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Clitoria fairchildiana R.A. Howard, commonly known as faveira, is an arboreal species used for reforestation and recommended for the recovery of degraded areas. The bark of the eucalyptus tree in the composition of the substrate for the emergence of faveira seedlings is assessed. Seeds were placed in plastic boxes with sand, soil, eucalyptus bark, sand and eucalyptus bark (3:1; 1:1; 1:3), soil and eucalyptus bark (3:1; 1:1; 1:3) and sand, eucalyptus bark and soil (1:1:1; 1:2:1; 1:4:1) and maintained in a greenhouse. Percentage, emergence speed and biometry of the faveira seedlings were evaluated. The emergence of faveira seedlings is less affected by the eucalyptus proportion in the substrate (soil and/or sand) when compared to the seedlings´ strength. The most adequate substrates for the emergence of faveira seedlings are sand (A), ground eucalyptus bark (C), Soil (S) and (S) + C (3:1), S + C (1:3), A + C (3:1) and A + C (1:3). [ABSTRACT FROM AUTHOR]

Life history traits are considered key indicators of plant invasibility. Among them, the germination behavior of seeds is of major relevance because it is influenced by environmental factors of invaded ecosystem. Here, we investigated how seed traits and seed tolerance to environmental factors on seed germination of Calotropis procera vary depending on the invaded ecosystems in northeastern Brazil. We have tested seeds from two vegetation types – Caatinga and Restinga – to different levels of light intensity, salinity, and water stress. Previous to those experiments, seed-set and morphometric analysis were carried out for both studied populations. We have observed a higher seed-set in Caatinga. Seeds produced in this ecosystem had lower seed moisture content. Seeds from Restinga showed lower germination time when light intensity decreased. We observed a reduction in both the germinability and the synchronization index with decreasing osmotic potential and increasing salinity. Nevertheless, both populations exhibited changes in photoblastism when seeds were submitted to water and saline stress. In conclusion, C. procera seeds are tolerant to environmental factors assessed. That characteristic ensures the colonization success and wide distribution of this plant species in the studied ecosystems.

Abutilon theophrasti and Barnyardgrass (Echinochloa crus-galli) are major weeds that affect cropping systems worldwide. Laboratory and greenhouse studies were conducted to determine the effects of temperature, pH, water and salinity stress, and planting depth on seed germination and seedling emergence of Velvetleaf and Barnyardgrass. For Velvetleaf, the base, optimum and ceiling germination temperatures were estimated as 5, 35 and 48 ºC, respectively. Seed germination was sensitive to drought stress and completely inhibited by a potential of -0.6 MPa, but it was tolerant to salinity. Salinity stress up to 45 mM had no effect on the germination of Velvetleaf, but germination decreased with increasing salt concentration. Drought and salinity levels for 50% inhibition of maximum germination were -0.3 MPa and 110 mM, respectively. Seed germination of Velvetleaf was tolerant to a wide range of pH levels. For Barnyardgrass, the base, optimum and ceiling germination temperatures were estimated as 5, 38 and 45 ºC, respectively. Seed germination was tolerant to drought stress and completely inhibited by a potential of -1.0 MPa. Salinity stress up to 250 mM had no effect on seed germination. Drought and salinity levels for 50% inhibition of maximum germination were -0.5 MPa and 307 mM, respectively. A high percentage of seed germination was observed at pH=5 and decreased to 61.5% at acidic medium (pH 4) and to 11% at alkaline medium (pH 9). Maximum seedling emergence of Velvetleaf and Barnyardgrass occurred when the seeds were placed on the surface of the soil or at a depth of 1 cm.Abutilon theophrastie Echinochloa crus-galli são as principais plantas daninhas que afetam os sistemas de cultivo em muitas partes do mundo. Estudos em laboratório e em casa de vegetação foram conduzidos para determinar os efeitos da temperatura, pH da água e estresse salino e da profundidade de semeadura na germinação e na emergência das plântulas de A. theophrasti e E. crus-galli. Para A. theophrasti, as temperaturas de base, ótima e de teto de germinação foram estimadas em 5, 35 e 48ºC, respectivamente. A germinação das sementes foi sensível ao estresse hídrico e inibida completamente por um potencial de -0,6 MPa, mas foi tolerante à salinidade. Estresse salino de até 45 mM não teve nenhum efeito sobre a germinação de A. theophrasti, porém esta diminuiu com o aumento da concentração salina. Os níveis de seca e de salinidade para 50% de inibição da germinação máxima foram de -0,3 MPa e 110 mM, respectivamente. A germinação das sementes de A. theophrasti foi tolerante a uma vasta gama de níveis de pH. Para E. crus-galli, as temperaturas de base, ótima e de teto de germinação foram estimadas em 5, 38 e 45ºC, respectivamente. A germinação das sementes foi tolerante ao estresse hídrico e inibida completamente a um potencial de -1,0 MPa. Estresse salino de até 250 mM não teve efeito sobre a germinação das sementes. Os níveis de seca e de salinidade para 50% de inibição da germinação máxima foram de -0,5 MPa e 307 mM, respectivamente. Elevada porcentagem de germinação das sementes foi observada a pH=5, com diminuição para 61% em meio ácido (pH=4) e para 11% em meio alcalino (pH=9). A máxima emergência das plântulas de A. theophrasti e E. crus-galli ocorreu quando as sementes foram colocadas sobre a superfície do solo ou a uma profundidade de 1 cm.

Objetivou-se com este trabalho avaliar a sensibilidade à dessecação e a longevidade durante o armazenamento de sementes de Eugenia pyriformis Cambess. (uvaia). Os frutos utilizados foram coletados em matrizes localizadas na cidade de Amambai-MS. Para o estudo da sensibilidade à dessecação, foi utilizado o protocolo baseado na redução do nível de hidratação das sementes a cada cinco pontos percentuais, obtendo-se sementes com teores de água de 45; 40; 30; 25; 20; 15; 10 e 5%. Para estudar a longevidade das sementes durante o armazenamento, foram testadas as condições de câmara fria e seca (16±1Cº/40% UR), geladeira (5±1Cº) e freezer (-18±1ºC) durante 30 dias, e as sementes que não foram submetidas ao armazenamento constituíram o tratamento-controle. A semeadura foi realizada entre areia a 20/30ºC com 10h de luz/14h de escuro em B.O.D. As sementes de uvaia são sensíveis à dessecação e não toleraram a secagem a 5% de teor de água. As sementes recém-beneficiadas apresentaram germinação de aproximadamente 77% e com a secagem até 5% houve a redução para 15% de germinação. A diminuição do teor de água provocou a redução da massa fresca, comprimento de raiz primária, hipocótilo e total de plântulas e tempo médio de germinação. As condições de armazenamento sob temperaturas baixas e a secagem reduziram a germinação das sementes, indicando assim o comportamento recalcitrante das sementes de uvaia.

O objetivo do presente trabalho foi à verificação do efeito alelopático de Hyptis. suaveolens na germinação de sorgo, alface e rabanete, bem como, a comprovação da existência de compostos com potencial alelopático. Sementes de sorgo, alface e rabanete foram semeadas em substrato constituído de areia, terra e adubo orgânico contendo folhas de H. suaveolens. As análises da germinação foram feitas considerando a protrusão da radícula para o término do evento germinativo. Foi calculado o IVG (índice de velocidade de germinação) e %G (porcentagem de germinação). Os resultados mostraram que sorgo e a alface foram mais susceptíveis ao potencial alelopático de H. suaveolens, sendo que para o rabanete foi observado um efeito benéfico. Entre os tratamentos, o substrato esterilizado e não esterilizado mostraram diferenças entre si. A análise cromatográfica do óleo essencial presente nas folhas de H. suaveolens revelou a presença de compostos com potencial alelopático. Portanto, H. suaveolens, pode apresentar efeito alelopático positivo no IVG de sementes de rabanete e a presença de microorganismos pode ser necessária para que esse efeito alelopático aconteça.The aim of this study was to verify the allelopathic effect of H. suaveolens on the germination of sorghum, lettuce and radish, as well as to prove the existence of compounds with allelopathic potential. Seeds of sorghum, lettuce and radish were sown in substrate consisting of sand, soil and organic fertilizer containing leaves of H. suaveolens. The germination tests were performed considering the protrusion of the radicle for the conclusion of the germinative event. GSI (germination speed index) and G% (percentage of germination) were calculated. The results showed that sorghum and lettuce were more susceptible to the allelopathic potential of H. suaveolens, while for radishes a beneficial effect was observed. Between treatments, the sterilized and unsterilized substrate showed differences. The chromatographic analysis of essential oil present in the leaves of H. suaveolens revealed the presence of compounds with allelopathic potential. Therefore, H. suaveolens may have positive allelopathic effect on the GSI of radish seeds, and the presence of microorganisms may be necessary for such an allelopathic effect to occur.

Smilax L. species, popularly known in Brazil as salsaparrilha, have been used in folk medicine as tonic against rheumatism and as anti-syphilitic since the sixteenth century; however, until today, their roots have been explored in an extractive way. The aim of this study was to analyze the propagation of Smilax fluminensis aiming to meet the demand and to propose procedures for its sustainable management. It was analyzed the percentage of seed germination, rooting of aerial and subterranean stem cuttings and plant resprouting capacity after removal of the shoots. The monitoring lasted one year. Seeds were subjected to temperatures: 25°C, 30°C, 20-30°C and 20-35°C under a daily photoperiod of eight hours and in the absence of light. For rooting the stem cuttings, aerial and subterranean stems about 20cm long with two nodal regions were subjected to treatment with distilled water (control) and indolbutyric acid (IBA) at 100ppm. The best germination percentages obtained for S. fluminensis were 80% at 20-30°C under light and 85% at 30°C in the dark. Only subterranean stem cuttings showed significant difference concerning fresh and dry matter of roots with higher values in treatments with hormone compared to the control.As espécies do gênero Smilax L., conhecidas popularmente como salsaparrilha, são empregadas na medicina popular como fortificante contra o reumatismo e antissifilítico desde o século XVI, porém até hoje as suas raízes são exploradas de maneira extrativista. O objetivo deste estudo foi analisar a propagação de Smilax fluminensis visando a auxiliar no atendimento da demanda e apontar propostas para o seu manejo sustentável. Foram analisados a porcentagem de germinação de sementes, o enraizamento de estacas de ramos aéreos e subterrâneos e o acompanhamento ao longo de um ano da capacidade de rebrotamento das plantas após a retirada dos ramos aéreos. As sementes foram submetidas às temperaturas: 25, 30, 20-30 e 20-35°C, sob fotoperíodo diário de oito horas e na ausência de luz. Para o enraizamento de estacas, foram utilizados ramos aéreos e subterrâneos com aproximadamente 20cm com duas regiões nodais submetidas ao tratamento com água destilada (controle) e com ácido indolbutírico (AIB) a 100ppm. As melhores porcentagens de germinação obtidas para S. fluminensis, 80% em 20-30°C no claro e 85% a 30°C no escuro. Apenas as estacas de ramos subterrâneos enraizaram, houve diferença significativa em relação à massa fresca e seca de raízes com valores maiores nos tratamentos com hormônio em relação ao controle.

In the present work, we analyzed the histochemical aspects of Passiflora edulis seeds reserve mobilization during the first ten days of germination. Our results showed that mainly lipids present in the endosperm are used as a reserve source, and their levels reduce at the same time the radicle protrudes, between the fourth and sixth day of sowing. Furthermore, protein bodies are present in the cotyledons, which are degraded as germination occurs and are almost depleted by the time of radicle protrusion. Starch grains also appear in the late germination period, and it is not clear if there is any reserve wall polysaccharide consumption in the endosperm.No presente trabalho analisamos os aspectos histoquímicos da mobilização de reservas das sementes de Passiflora edulis, durante os primeiros dez dias de germinação. Nossos resultados mostraram que principalmente lipídios presentes no endosperma são utilizados como reserva, com o seu nível começando a diminuir ao mesmo tempo em que ocorre a protrusão da radícula, entre o quarto e sexto dia do início da embebição. Corpos proteicos também estão presentes nos cotilédones, e são degradados à medida que ocorre a germinação e são consumidos quase totalmente quando da protrusão da radícula. Grãos de amido também aparecem no período tardio de germinação, e não está claro se há ou não consumo de polissacarídeos de reserva de parede no endosperma.

Two main hypotheses predominate in the literature on mistletoe-host specificity: (1) mistletoes are only likely to specialize on plant species on which they are frequently deposited; and (2) compatibility between mistletoes and plant species is a prerequisite for mistletoe-host parasitism. I explored these hypotheses by studying the seed deposition patterns and mistletoe-host compatibility in populations of three congeneric and sympatric mistletoe species of the genus Psittacanthus (P. biternatus, P. eucalyptifolius and P. plagiophyllus - Loranthaceae). I recorded the presence or absence of these mistletoe species in 15 tree species in a savanna patch in Amazonia. Among the five tree species that I found to be potential hosts (at least one tree individual infected), I also recorded if they had at least one mistletoe seed of any species attached to their branches. Finally, I planted seeds of all mistletoe species on the same individual trees in various hosts and non-host species and recorded seed survivorship and seedling establishment within 7 (P. plagiophyllus) to 12 months (P. biternatus and P. eucalyptifolius) after planting. There was no overlap among trees used as hosts by the three Psittacanthus species. Th e most specialized mistletoe species occurred in different host tree species with low relative abundance at the study site (Psittacanthus eucalyptifolius on Vatairea macrocarpa (Benth.) Ducke, and P. plagiophyllus on Anacardium occidentale L.). Mistletoe-host compatibility, and not seed deposition patterns, was the factor most likely to explain patterns of host use by Psittacanthus species at this study site.Duas hipóteses principais predominam na literatura sobre a especificidade entre ervas-de-passarinho e hospedeiros: (1) ervas-de-passarinho só poderão se especializar em espécies de plantas em que elas são frequentemente depositadas; e (2) compatibilidade entre as ervas-depassarinho e as espécies de plantas é um prerequisito para o parasitismo. Explorei estas hipóteses com o estudo dos padrões de deposição de sementes e a compatibilidade entre ervas-de-passarinho e hospedeiros em populações de três espécies de ervas-de-passarinho congenéricas e simpátricas do gênero Psittacanthus (P. biternatus, P. eucalyptifolius and P. plagiophyllus - Loranthaceae) e registrei a presença ou ausência destas três espécies em 15 espécies de árvores em uma mancha de savana na Amazônia. Entre as cinco espécies de árvores que eu encontrei infectadas, também registrei se elas possuíam pelo menos uma semente de erva-de-passarinho de qualquer das espécies aderida aos seus galhos. Finalmente, plantei sementes de todas as espécies de ervas-de-passarinho nas mesmas árvores em várias espécies de hospedeiros e não-hospedeiros e registrei a sobrevivência das sementes e o estabelecimento ao final de 7 (P. plagiophyllus) e 12 meses (P. biternatus e P. eucalyptifolius). Não houve sobreposição entre as árvores utilizadas como hospedeiros pelas três espécies de Psittacanthus. As espécies de ervas-de-passarinho mais especializadas ocorreram em diferentes espécies de hospedeiros com baixa abundância relativa na área de estudo (Psittacanthus eucalyptifolius em Vatairea macrocarpa (Benth.) Ducke, e P. plagiophyllus em Anacardium occidentale L.). A compatibilidade entre a erva-de-passarinho e o hospedeiro, e não o padrão de deposição de sementes, foi o fator mais propício a explicar os padrões de uso de hospedeiros por Psittacanthus neste local.

The emergence of weed plants depends on environmental conditions, especially temperature and soil moisture. The latter is extremely important in Mediterranean environments which are characterized by irregular amount and distribution of rain throughout the year, which influences the beginning of the growth cycle of the annual species (seed germination). This paper studies the influence of rainfall, in particular accumulated rainfall in autumn, on the emergence of weed plants. The experiment was carried out on Luvisols, and the appearance of flora under field conditions was observed. Through analysis of the results, it can be concluded that a high percentage of weed plants (> 85% related to the highest registered value) was obtained with more than 90 mm of accumulated rainfall from the beginning of September. Thus, in those years in which this amount of rainfall (90 mm) is registered until the end of October, the appearance of potential weed plants can be ensured, under Mediterranean conditions, in a period before sowing the autumn-winter crops.A emergência de plantas daninhas depende das condições ambientais, sobretudo da temperatura e da umidade. Esta é de extrema importância em ambientes mediterrânicos, caracterizados pela irregularidade da quantidade de precipitação e da sua distribuição durante o ano, que influencia o início do ciclo vegetativo das espécies anuais (germinação de sementes). Neste trabalho, estudouse a influência da precipitação, particularmente a quantidade acumulada no outono, na emergência de plantas daninhas. O experimento foi realizado em Luvisols, tendo sido registrado o aparecimento da flora em condições de campo. De acordo com a análise dos resultados, conclui-se que elevadas densidades populacionais de plantas daninhas (> 85% relativamente ao valor máximo verificado) foram obtidas com uma precipitação acumulada desde o início de setembro superior a 90 mm. Assim, nos anos em que se registra essa quantidade de precipitação até o fim de outubro (90 mm), garantirseá, em condições mediterrânicas, o aparecimento da flora potencial numa época em que pode ser controlada antes da semeadura das culturas de outono-inverno.

Tabebuia serratifolia, Tabebuia chrysotricha and Tabebuia roseo-alba (Bignoniaceae), are an important ornamental and wood trees in Brasil. The effects of light and temperature in the germination of Tabebuia serratifolia, Tabebuia chrysotricha and Tabebuia roseo-alba seeds were studied in the present work. The results indicated that the species present light insensitive seeds the and optimum temperature was between 20° and 30°C, the maximum temperature between 35° and 40°C and minimal temperature between 10° and 15°C for Tabebuia chrysotricha and Tabebuia roseo-alba and below 10°C for Tabebuia serratifolia.

Durante a germinação e o desenvolvimento pós-germinativo de milho, o fluxo metabólico é intenso, ocorrendo síntese e degradação de açúcares (glicose, frutose e sacarose) e hidrólise de amido, além da redução da concentração do ácido abscísico (ABA). Acredita-se que altas concentrações de glicose exógena, promovam acúmulo de ABA, proporcionando atraso na germinação e desenvolvimento de plântulas. Concentrações menores, por outro lado, podem ocasionar estímulo na germinação e desenvolvimento. Neste trabalho, foi observado que a glicose (800 µM) estimulou a germinação e o desenvolvimento inicial de genótipo de milho comum e retardou, severa ou brandamente, genótipos de milho doce (su1), provavelmente devido às diferentes concentrações endógenas de glicose de cada genótipo. Foi visto, também, que a concentração de 1,2 ηM de insulina foi capaz de estimular o maior desenvolvimento de genótipos de milho comum (UENF 506-8) e doce H43IN e nula para o genótipo doce HDC. Quando adicionada insulina e glicose ao meio, foi obtido efeito aditivo para o desenvolvimento. Esses resultados sugerem que a insulina e glicose apresentam forte influência na germinação e no desenvolvimento de sementes de milho.During germination and development of corn seeds the metabolic flow is intense, the synthesis and degradation of sugars (glucose, fructose and sucrose) and hydrolysis of starch, besides to the decrease in abscisic acid (ABA) concentration are some of the major events. High concentrations of exogenous glucose are believed to promote accumulation of ABA, causing delay in the germination and development of seedlings, while lower concentrations stimulated the germination and development. In our studies it was verified that 800 µM glucose stimulated the germination and initial development of the common corn genotype and delayed severely or softly for sweet corn (su1) genotypes, probably due to different glucose endogenous concentrations of each genotype. It was also verified that 1.2 ηM insulin was capable to stimulate the development for the common corn and sweet H43IN genotypes and did not affect HDC sweet genotype development. These events may have happened due to metabolic differences in the mutants. When insulin and glucose were added to the medium, addictive effects on the development were observed. These results suggest that both insulin and glucose have strong influence on germination and development of corn seeds.

Metabótitos secundários produzidos em algumas plantas podem provocar alterações no desenvolvimento de outras plantas ou até mesmo de outros organismos. Neste trabalho, objetivou-se identificar possíveis efeitos alelopáticos de extratos aquosos de folhas de Cyperus rotundus na germinação e no crescimento de plântulas de Brassica campestris, Brassica oleracea var. botrytis, Brassica oleracea var. capitata, Brassica oleracea var. italica, Brassica rapa, Lactuca sativa cv. Grand rapids, Lycopersicum esculentum e Raphanus sativus. Foram utilizadas sete concentrações do extrato aquoso (0, 10, 30, 50, 70, 90 e 100%). Os tratamentos foram arranjados em delineamento inteiramente casualizado, com cinco repetições de dez sementes das espécies cultivadas, constituindo a unidade amostral. Os extratos aquosos de C. rotundus evidenciaram potencialidades alelopáticas na germinação das sementes e no crescimento das duas partes vegetais (raiz e parte aérea), de todas as espécies testadas, exceto na germinação de sementes de tomate e de alface, sendo que a redução aumentou com o aumento das concentrações dos extratos aquosos utilizados. A estrutura vegetal mais afetada em presença dos extratos aquosos foi o sistema radicular das plântulas.Secondary metabolites produced in some plant species may promote changes in the development of other plants or even in other organisms. The aim of this work was to identify the possible allelopathic effects of aqueous extracts of Cyperus rotundus leaves on germination and growth of Brassica campestris, Brassica oleracea var. botrytis, Brassica oleracea var. capitata, Brassica oleracea var. italica, Brassica rapa, Lactuca sativa cv. Grand rapids, Lycopersicum esculentum and Raphanus sativus seedlings. Seven aqueous extract concentrations were used (0, 10, 30, 50, 70, 90, and 100%). The treatments were arranged in a completely randomized desing, with five replications of ten seeds of each cultivated species constituting the sample unity. The aqueous extracts of C. rotundus revealed allelopathic potentialities on germination of seeds and growth of two vegetable parts (root and aerial part) of all tested species, except on germination of L. sativa and L. esculentum seeds, being that the reduction increased with the increase of the aqueous concentration extracts which were used. The seedlings roots were the most affected structure in the presence of aqueous extracts.

O capim-elefante é uma das gramíneas de maior potencial para produção de leite e carne a pasto. Entretanto, a forma de multiplicação por estacas dificulta a sua maior expansão. O cruzamento interespecífico envolvendo o milheto visa, entre outras coisas, o aumento do tamanho das sementes facilitando a sua propagação. Objetivou-se no presente trabalho, verificar o potencial de germinação de sementes em diferentes progênies de capim-elefante hexaplóide para confirmação da viabilidade de propagação dessa forrageira, por meio de sementes. O experimento foi conduzido na Embrapa Gado de Leite e foram avaliadas 78 progênies de meio-irmãos de capim-elefante hexaplóide. Empregou-se o delineamento de blocos casualizados, com três repetições e parcelas de 100 sementes. Em cada parcela foram realizadas três contagens do número de sementes germinadas, em intervalos de sete dias, para obtenção da porcentagem de germinação das sementes. Observaram-se diferenças significativas entre os tratamentos evidenciando a existência de variabilidade no potencial de multiplicação por sementes das progênies de meio-irmãos de capim-elefante hexaplóide. A amplitude de variação para a porcentagem de germinação das sementes foi de 48,67%. As médias das progênies foram divididas em seis grupos pelo teste de Scott-Knott e as progênies 64, 53, 19, 62, 2, 45, 72, 10 e 77 apresentaram melhor desempenho, com germinação das sementes superior a 35%.Elephant grass is a grass with one of the highest potential for milk and beef production under grazing conditions. However, its utilization is limited due to the dissemination method that uses stems for pasture formation. The interespecific cross with pearl-millet, aims to obtain seeds of bigger size to facilitate the propagation of elephant grass. The objective of this paper was to verify the germination potential of different progenies of elephant grass hexaploid seeds to confirm the viability of this dissemination method. The experiment was carried out at Embrapa Gado de Leite, evaluating 78 half-sib progenies of hexaploid elephant grass in a complete randomized block design with three replications and 100 seeds per experimental unit. Three counting of germinated seeds were done in each experimental unit every seven days. Significant differences were observed between progenies showing the existence of variability in the potential for the dissemination when using seeds originated from half-sib progenies of hexaploid elephant grass. The range of variation for seed germination was 48,67%. The progenies were divided into six groups by the Scott-Knott test and the progenies 64, 53, 19, 2, 45, 72, 10 and 77 presented the best germination rate, with values above 35%.

Plantago ovata é espécie medicinal de grande importância cultivada na Índia, no Irã e no Paquistão. Suas sementes possuem de 20 a 30% de mucilagem, utilizada pelas indústrias farmacêuticas nos tratamentos de constipação crônica, câncer intestinal e amebíase. A Índia é o principal exportador mundial de sementes de Plantago ovata, e o produto comercial originado dessas sementes, no Brasil, leva o nome de Agiolax. Este trabalho teve como objetivo verificar o efeito da luz e temperatura na germinação de sementes dessa espécie. Para tanto, foram utilizadas quatro repetições com 50 sementes cada uma, colocadas para germinar em papel-filtro umedecido com 12 mL de água destilada, nas temperaturas de 5 a 35 ºC, com intervalos de 5 ºC, na ausência e presença de luz. As sementes germinaram tanto na luz quanto no escuro e apresentaram comportamento de fotoblásticas neutras na faixa de temperatura de 10 a 25 ºC, com faixa ótima de 20 a 25 ºC, em que ocorreram maiores porcentagens e velocidade de germinação.Plantago ovata is a medicinal species of great importance cultivated in India, Iran and Pakistan.The seeds are known to contain 20 to 30% of mucilage, and are used by pharmaceutical industries in the treatment of chronic constipation, intestinal cancer and amoeba. India is the main world-wide exporter of Plantago ovata seeds.In Brazil, this species is known by the corporate name of Agiolax. The present work aimed to verify the effect of light and temperature on the germination of seeds of this species. Thus, 4 replications were used, each with 50 seeds put to germinate in filter paper humidified with 12mL distilled water, at 5 and 35Cº,at intervals of 5ºC, in the absence and presence of light. The seeds germinated both in the light and dark, presenting a neutral photoblastic behavior at the temperature range of 10 and 25ºC, with optimal range at 20 and 25ºC, when higher percentages and germination speed were verified.

Estudaram-se parâmetros indicativos da maturação de frutos de árvores de Caesalpinia echinata, visando determinar a melhor época de colheita para propagação. Foram utilizadas 10 plantas-matriz cultivadas em Mogi-Guaçu, SP, nas quais foram etiquetadas 250 inflorescências no pico da floração para acompanhamento da maturação. As coletas de frutos tiveram início a partir da 5ª semana após a antese, prolongando-se até a 9ª, com intervalos de sete dias. Em cada coleta, analisaram-se os parâmetros: comprimento, largura e teor de água dos frutos; teor de água das sementes (após três dias de exposição ao sol para deiscência do fruto e extração da semente); porcentagem de germinação e peso de matéria seca de frutos, sementes e plântulas. Observou-se, ainda, a coloração dos frutos como parâmetro visual de maturação das sementes. O experimento foi repetido por três anos. Os testes de germinação foram realizados em caixas Gerbox contendo vermiculita umedecida com água destilada. As sementes foram colocadas para germinar em câmara regulada para 30 ºC e fotoperíodo de 12 horas O delineamento estatístico utilizado foi inteiramente casualizado com quatro repetições de 25 sementes por parcela, nos anos de 1991, 1992 e 1993. As leituras de germinação foram realizadas nos 4º e 8º dias após a semeadura. Pelos resultados, conclui-se que o momento ideal para coleta dos frutos de C. echinata é no estádio de pré-dispersão (entre a 8º e 9º após a antese) visualizado através da coloração, quando estes mudam de verde para castanho.Several indicative parameters regarding fruit maturity of Caesalpinia echinata were studied in order to establish the ideal harvest time. Ten matrix plants were cultivated in Moji-Guaçu, SP (22°11' to 1022°18' S and 47°13' to 47°20' WG), altitude between 600m and 730m. The climate of the region is classified as Cwa. Two hundred and fifty blossoms were tagged during the the peak blooming period for maturation analysis. Fruit-harvesting schedule ranged from the fifth to the ninth week after anthesis, with seven-day intervals. The following parameters where analyzed for each harvest: fruit length and width; fruit moisture content; seed moisture content (after natural pre-drying); germination percentage; seed, fruit and seedling dry matter weight. Fruit colors were also observed and used as a visual parameter of seed maturation. The experiment was repeated for three years. The germination tests were performed in Gerbox boxes, with vermiculite watered with distilled water. The seeds were set to germinate in B.O.D cameras, at 30°C, with a 12-hour photoperiod. The experimental design was completely randomized with four replications of 25 seeds per plot in 1991, 1992 and 1993. The germination was analyzed on the 4th and 8th days after seeding. The results showed that the ideal harvest time for Brazil-wood fruits is at the pre-dispersion stage, which can be identified visually through colors, when they change from green to chestnut-brown.

Na Amazônia as áreas inundáveis são cobertas por florestas com alta diversidade de espécies arbóreas que proporcionam a ictiofauna frutos e sementes indispensáveis a sua alimentação. Alguns estudos de alimentação têm mostrado que a estrutura tegumentar de sementes encontradas no trato digestório de peixes, se apresentavam intactas. Assim, este estudo teve como objetivo verificar se Triportheus angulatus (Spix & Agassiz, 1829) pode ser um agente dispersor de Bothriospora corymbosa (Bth) Hook. f. (Rubiaceae). A pesquisa foi desenvolvida no lago Camaleão, Ilha da Marchantaria, Manaus. Após a captura os peixes foram levados ao laboratório de campo, para a remoção do conteúdo do trato digestório, de onde foram retiradas 200 sementes para o experimento. As sementes do controle foram retiradas de frutos maduros. A germinação e emissão da radícula foram controladas diariamente. Neste estudo verificou-se que a principal fonte de alimento de T. angulatus foram frutos e sementes de espécies da várzea. O desempenho germinativo das sementes de B. corymbosa após a passagem pelo trato digestório de T. angulatus foi de 88,5% e do controle 95%. Os Índices de Velocidade de Germinação (IVG) das sementes do trato digestório e do controle apresentaram diferenças significativas, porém, a passagem destas pelo intestino de T. angulatus não alterou a sua viabilidade. Assim, T. angulatus é um dos agentes dispersores de B. corymbosa, contribuindo com a distribuição desta espécie nas florestas de várzea da Amazônia Central.The Amazon floodplains are covered by forests with a high diversity of tree species that provides ictyofauna indispensable fruits and seeds for its feeding. Some studies of feeding have shown that the tegument structure of seeds found in the digestive tract of fish presented unbroken. Thus, this study had as objective to verify if Triportheus angulatus (Spix & Agassiz, 1829) can be dispersal agent of Bothriospora corymbosa (Bth) Hook. f. (Rubiaceae). The research was developed in the Camaleão Lake, Island of the Marchantaria, Manaus. After the capture the fishes had been taken to the field laboratory, for the removal of the digestive tracts content, where 200 seeds for the experiment had been removed. The seeds of the control had been removed of ripe fruits. The germination and initial radicle emission were controlled daily. In this study it was verified that the main food source of T. angulatus had been fruits and seeds. The germinative performance of the seeds removed from digestive tract was of 88.5% and control 95%. The Indices of Speed Germination (IVG) of the seeds which had passed through the digestive system and the control, presented significant differences, however, the passage of these through the intestine of T. angulatus did not modify its viability. Thus, T. angulatus is one of the dispersal agents of B. corymbosa, contributing with the distribution of this species in the floodplain forests of the Central Amazonian.

Este estudo descreve os aspectos morfológicos dos frutos, sementes e desenvolvimento das plântulas e plantas jovens de Maclura tinctoria. A biometria de frutos e sementes foi descrita a partir de amostras de 100 unidades e os testes de germinação foram realizados em câmara de germinação e em viveiro de mudas. O fruto possui forma oblonga, formado de núculas comprimidas, pericarpo carnoso e doce, indeiscente, de coloração amarelo-esverdeada quando maduro. A semente madura é achatada lateralmente, ligeiramente ovalada, com coloração creme e superfície lisa. A taxa de germinação foi alta de aproximadamente 92% em câmara de germinação e 90% em viveiro de mudas. A plântula é epígea-foliácea. As plantas jovens apresentam, folhas simples, alternadas, levemente membranáceas, pilosas, ligeiramente ovaladas, serrilhadas, com ápice agudo e base rotunda. A venação é pinada com padrão semi-craspedódromo. Esses resultados possibilitam fácil reconhecimento da espécie no banco de plântulas e para estudos posteriores em projetos de recomposição vegetal.This study describes the morphological aspects of fruits and seeds, and the development of seedlings and saplings of Maclura tinctoria. The biometry of fruits and seeds was described from 100-unit samples, and germination tests were carried out in a germination chamber and also in the greenhouse. The fruit is oblong and is formed by compressed nutlets, with a sweet, fleshy pericarp; it is indehiscent, and greenish-yellow when mature. The mature seed is laterally flattened, slightly oval, cream-colored and with a smooth surface. Germination rates were high, both in the germination chamber (92%) and the greenhouse (90%). Initial seedling morphology follows the epigeous-phanerocotylar type. Saplings have simple, alternate leaves, which are slightly oval and membranous, pilose, serrulate, with acute apex and rotund base. Venation is pinnate with a semi-craspedodromous pattern. These results allow easy identification of this species in seedling banks and for future studies of forest restoration.

This study was performed to evaluate the immediate and latent effects of drying air temperature on the physiological potential of peanuts (Arachis hypogaea L.). The fruits were harvested at the physiological maturity stage, with 36 ± 2% water content (w.b.), and dried at temperatures of 40, 50, 60 and 70°C, until 7 ± 1% (w.b.). Thereafter, the fruits were stored in an environment with non-controlled temperature and relative humidity for 150 days, and the water content, germination and vigor of seeds were immediately determined, as well as at every 30 days thereafter, through the first count, and the tetrazolium test, accelerated aging test, cold test with soil and electrical conductivity. According to the results, it was found that the physiological potential of peanut seeds is inversely related to the drying temperature and the storage time, due to the fact that the germination and vigor are reduced as both factors increase. The air temperature of 40 °C may be recommended for the drying of peanut seeds, and even associated with the storage time of 150 days under uncontrolled conditions. [ABSTRACT FROM AUTHOR]

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As espécies de ipê (Tabebuia serratifolia, Tabebuia chrysotricha e Tabebuia roseo-alba) são árvores de interesse econômico madeireiro, ornamental e indicadas em programas de reflorestamentos. Neste trabalho, foram testadas as temperaturas constantes de 10°C a 40°C, em condições de luz e escuro dentro de germinadores. Os resultados indicaram que as sementes das três espécies de Tabebuia são indiferentes à luz, com a faixa de temperatura ótima entre 20° e 30°C, a temperatura máxima entre 35° e 40°C e a temperatura mínima entre 10°e 15°C para Tabebuia chrysotricha e Tabebuia roseo-alba e abaixo de 10°C para Tabebuia serratifolia.

Marcetia taxifolia (A. St.-Hil.) DC. (Melastomataceae) é um arbusto amplamente distribuído nos campos rupestres da Serra do Cipó, Brasil. É uma espécie com potencial na recuperação de áreas degradadas e este estudo apresenta os primeiros dados sobre o efeito da luz e da temperatura na germinação de suas sementes. Sementes foram coletadas em maio/2001 e foram submetidas a testes de germinação nas temperaturas constantes de 15, 20, 25, 30 e 35ºC sob fotoperíodo de 12 horas e em ausência de luz durante 30 dias. Foram encontradas diferenças significativas entre a percentagem de germinação e tempo médio de sementes submetidas ao tratamento claro e escuro a 15, 20, 25 e 30ºC (p < 0,05; todos). Sob a temperatura de 35ºC, a germinação foi completamente inibida. As maiores percentagens de germinação foram obtidas a 15 e 20ºC, as quais foram superiores a 25 e 30ºC (ANOVA = 13,65; p < 0,001). Os dados contribuem para estudos posteriores que visem a propagação da espécie com fins de reabilitação ambiental.Marcetia taxifolia (A. St.-Hil.) DC. (Melastomataceae) is a shrub widely distributed in the rupestrian fields of Serra do Cipó, Brazil. In spite of M. taxifolia being a potential species to be used in land rehabilitation, no complete study has been conducted regarding its seed germination. The goal of this work was to evaluate the effect of light and temperature on seed germination of M. taxifolia. Seeds were collected in May/2001 and were submitted to germination tests at constant temperatures of 15, 20, 25, 30 and 35ºC under a photoperiod of 12 hours, and in the absence of light for 30 days. There were statistically significant differences between seed germination and mean time of germination for seeds submitted to the light and dark treatments at 15, 20, 25 and 30ºC (p < 0,05; all). Seed germination under 35ºC was totally inhibited. The higher germination percentages were obtained at 15 and 20ºC, which differed significantly from the temperatures of 25 and 30ºC (ANOVA = 13,65; p < 0,001). The data contribute to further studies focusing the propagation of M. taxifolia for land rehabilitation purposes.

O objetivo deste trabalho foi avaliar a qualidade fisiológica de sementes de quatro espécies da família Palmae submetidas ao envelhecimento acelerado. Sementes recém-colhidas de cada uma das espécies foram expostas às condições de envelhecimento acelerado em câmara a 45ºC e 100% de UR, durante os períodos de 0 (controle), 12, 24, 36 e 48 horas. Sementes de Euterpe edulis e Dypsis lutescens foram sensíveis ao tratamento, sendo a germinação totalmente suprimida após 12 horas de permanência na câmara. As espécies Roystonea oleracea e Phoenix reclinata apresentaram sementes mais resistentes que as outras espécies, mas redução gradativa do vigor, de acordo com o aumento do período de exposição às condições de envelhecimento; o período de 48 horas foi crítico para determinados parâmetros de vigor avaliados.

Neste estudo verificou-se o comportamento germinativo de sementes de Lavoisiera cordata Cogn. e Lavoisiera francavillana Cogn. (Melastomataceae), espécies que ocorrem em hábitats com características hídricas e nutricionais diferentes nos campos rupestres da Serra do Cipó, Sudeste do Brasil. Sementes coletadas no ano de 2000 foram postas para germinar em quatro réplicas de 25 nas temperaturas de 15, 20, 25 e 30ºC, sob fotoperíodo de 12h. A percentagem de germinação foi mais alta para L. cordata do que para L. francavillana (t=11.803, gl = 30, p0.05, N.S.). As percentagens de germinação correlacionaramse positivamente com as velocidades de emergência para esta espécie (r²=0.63, p0.05, N.S.), sendo que as percentagens de germinação se correlacionaram positivamente com as velocidades de emergência (r²=0.90, p