Dry Mass Of Seedlings Research Articles

SUBSTRATES AND TEMPERATURES FOR THE GERMINATION OF SEEDS OF Senegalia tenuifolia (L.) BRITTON & ROSE

ABSTRACT: The Rules for Seed Analysis and the Instructions for Seed Analysis of Forest Species have no recommendations for conducting the S. tenuifolia germination test. Therefore, the aim of the present study was to evaluate different temperatures and substrates to perform the germination test of S. tenuifolia seeds. The experimental design was completely randomized in a factorial 4 × 3 design and consisted of four substrates (paper roll; on paper; on sand and on vermiculite) and three temperatures (25, 30 and 35 °C), with four replicates of 25 seeds. The percentage of normal seedlings, the germination speed index, the shoot length, root length and dry mass of seedlings were evaluated. The Tukey test was used at 5% probability. There was a significant interaction between the temperatures and substrates tested for all variables, indicating that there is at least one ideal combination of the two factors that can increase the germination of seeds. The germination and vigor of S. tenuifolia seeds are influenced by the temperature and by the substrate used in the germination test. The combination of the paper roll substrates with a temperature of 25 and 30 °C was suitable for the germination of S. tenuifolia seeds.

Campomanesia adamantium (Cambess.) O. Berg seed desiccation: influence on vigor and nucleic acids.

The aim of this study was to evaluate the sensitivity of Campomanesia adamantium seeds to desiccation by drying in activated silica gel (fast) and under laboratory conditions (slow). To assess the sensitivity of the seeds to desiccation, we used drying with silica gel and drying under laboratory conditions (25 °C), in order to obtain seeds with moisture content of 45, 35, 30, 25, 20, 15, 10 and 5%. The physiological potential of the seeds after desiccation was evaluated by measuring primary root protrusion, percentage of normal seedlings, germination seed index, seedling length, total seedling dry mass, electrical conductivity and DNA and RNA integrities. The C. adamantium seeds were sensitive to desiccation and to a reduction in moisture content to 21.1% or less by desiccation using silica gel, and to 17.2% or less by desiccation under laboratory conditions; impairment of the physiological potential of the seeds was observed at these low moisture content levels. The integrity of the seed genomic DNA was not affected after drying seeds in the two methods. However, drying in silica gel to 4.5% moisture content and drying under laboratory conditions to 5.4% moisture content resulted in the loss of seed RNA integrity.

Electrical conductivity test in Piptadenia moniliformis Benth. seeds

The electrical conductivity test is a quick, practical and objective test force; however, its effectiveness varies according to the species, quantity of seed, water volumes, soaking temperature, among other factors. The objective of this study was to evaluate the physiological quality of P.moniliformis seeds lots by means of the electrical conductivity test, testing different methodologies. For this, two lots were tested in three quantities of time (25, 50 and 75 seeds) and nine soaking times (2, 4, 6 , 12, 24 , 36, 48, 60 and 72 hours) in three volumes of water (50, 75 and 100 mL) at 25 °C. To evaluate the initial quality of the lots, germination percentage, germination speed index, average time of germination, length and dry mass of seedlings were determined. The use of the electrical conductivity test of P. moniliformis seeds is recommended using 75 seeds in 75 mL of water for 2 hours at 25 °C or seeds in 50 mL distilled water with 50 seeds per 6 hours at 25 °C.

Qualidade de sementes de feijão-azuki dessecadas com saflufenacil e submetidas ao armazenamento

RESUMO Objetivou-se, nesta pesquisa, avaliar o efeito do uso do herbicida saflufenacil como dessecante em pré-colheita e do armazenamento sobre a qualidade fisiológica e sanitária de sementes de feijão-azuki. Foram testadas seis doses do herbicida saflufenacil (0, 50, 75, 100, 150 e 200 g a.i. ha-1) e duas épocas de avaliação da qualidade das sementes: colheita e seis meses após a colheita. A aplicação do dessecante ocorreu na maturidade fisiológica do feijoeiro azuki e as sementes colhidas foram armazenadas em sacos de papel (Kraft) em ambiente natural, a 25,4 ± 3 ºC de temperatura e 67,3 ± 3% umidade relativa. O saflufenacil pode ser utilizado até a dose de 65 g a.i. ha-1 sem prejudicar a qualidade fisiológica das sementes. O armazenamento provocou queda na percentagem de germinação, aumento no número de plântulas anormais e redução no tamanho e da massa seca das plântulas. A dessecação em pré-colheita e o armazenamento reduzem a infestação Cladosporium, Fusarium, e Rizhopus nas sementes de feijão-azuki.

<b>Cadmium toxicity on seed germination and seedling growth of wheat <i>Triticum aestivum

Cadmium toxicity in seed germination and seedling growth of wheat ( Triticum aestivum , var. IAC-370) is assessed. The ecotoxicological effects of six experimental concentrations of cadmium (0.03; 0.06; 0.12; 0.6; 1.2; 2.4; 4.8 mM), and control were evaluated. All assays were performed in quadruplicates with 25 seeds per replication in Petri dishes. Responses for toxic effect comprised the variables germination percentage, index of velocity of germination (IVG), length of aerial section and root of the seedlings, green and dry mass of the seedlings. Results showed that T. aestivum seeds exposed to cadmium decreased their normal germination percentage as from 0.03 mM concentration, with a 31% reduction of germination percentage and a 20% decrease in IVG. Cadmium´s inhibition effect on initial growth of seedlings influenced growth of roots and aerial part as from concentration 0.12 mM and reduced the production of green and dry mass of seedlings as from 0.06 mM. The presence and accumulation of cadmium in the soil cultivated with T. aestivum may trigger liabilities in productivity and/or viability caused by its toxicity as from 0.03mM concentrations absorbed by the plant roots.

UMEDECIMENTO DO SUBSTRATO E TEMPERATURA NA GERMINAÇÃO DE SEMENTES DE<i> Parkia platycephala</i> BENTH.

http://dx.doi.org/10.5902/1980509819607A Parkia platycephala Benth. (faveira) é uma leguminosa arbórea, conhecida como fornecedora de madeiracomercial na Amazônia. O presente trabalho foi conduzido com o objetivo de avaliar diferentes volumesde água para umedecimento do substrato e temperaturas na germinação e vigor de sementes de Parkia platycephala. As sementes foram submetidas ao teste de germinação em papel-toalha, organizado naforma de rolos e umedecido com volumes de água equivalentes a 2,0; 2,5; 3,0 e 3,5 vezes o peso seco dosubstrato e colocadas nas temperaturas constantes de 20, 25, 30 e alternada de 20-30°C. Foram avaliados: aporcentagem de germinação, a primeira contagem de germinação e o índice de velocidade de germinação,o comprimento e a massa seca da raiz e da parte aérea das plântulas normais. O delineamento experimentalfoi o inteiramente ao acaso, com os tratamentos distribuídos em esquema fatorial 4 x 4 (quatro volumesde água e quatro temperaturas). O umedecimento do substrato com 2,0; 2,5; 3,0 e 3,5 vezes o peso dopapel nas temperaturas de 25, 30 e 20-30ºC pode ser utilizado para avaliação da germinação e vigor dassementes de Parkia platycephala Benth. A temperatura de 20ºC em todos os volumes de água testados paraumedecimento do substrato reduziu a germinação e o vigor das sementes.

Emergência e crescimento inicial de plântulas de Platymiscium floribundum Vog. em função de diferentes posições e profundidades de semeadura

Platymiscium floribundum Vog., pertencente à família Fabaceae, pode ser utilizada no paisagismo, em reflorestamentos e na recomposição de áreas degradadas e de preservação permanente. Objetivou-se verificar o efeito da posição da semente e da profundidade de semeadura na emergência e crescimento inicial de plântulas de P. floribundum. O experimento foi realizado em delineamento inteiramente ao acaso, utilizando-se diferentes posições das sementes no substrato areia: hilo voltado para baixo (HB), hilo voltado para o lado, formando um ângulo de 90° em relação ao eixo imaginário com o substrato (HL) e hilo voltado para cima (HC), nas profundidades de semeadura de 0, 1, 2, 3, 4, 5 e 6cm. Avaliou-se a porcentagem, primeira contagem e índice de velocidade de emergência de plântulas, assim como o comprimento e massa seca das plântulas normais. Para o teste de emergência de plântulas de P. floribundum, a semeadura deve ser na profundidade de até 2,0cm com o hilo voltado para baixo.

Effect of storage in overcoming seed dormancy of Annona coriacea Mart. seeds.

The aim of this study was to evaluate the effect of pre-treatments on overcoming dormancy of A. coriacea seeds. Seeds were processed and stored in polyethylene bags at temperatures of at -18°C (42% RH), 5°C (34% RH), 15°C (60% RH) and 25°C (34% RH), during 0, 30, 60, 90, 120 and 150 days. After storage, seeds were immersed in 350 mg.L-1 gibberellic acid for 144 hours. Sowing was carried out in plastic bags containing Red Latosol + Bioplant®. Moisture content, emergence percentage, emergence speed index, length and dry mass of seedlings, were evaluated. The experimental design was completely randomized in a factorial with four replications of 50 seeds each. The seed storage at 5°C and subsequent immersion in gibberellic acid was efficient to reach high percentage, emergence speed and plant growth. A. coriacea seeds showed non-deep simple morphophysiological dormancy wherein the physiological component can be overcome after the seeds are storage at 5°C for a maximum period of 53 days and subsequent immersed in exogenous GA (350 mg.L-1 for 144 hours).

Effects of continual burial by sediment on morphological traits and dry mass allocation of Suaeda salsa seedlings in the Yellow River estuary: An experimental study

Information on the effects of continual burial by sediment on seedling survival and morphological growth in coastal marsh remains scarce. A greenhouse experiment was conducted to determine the effects of continual burial on seedling mortality, growth and dry mass allocation of Suaeda salsa in the coastal marsh of the Yellow River estuary. The seeds were planted at 0.5cm depth in plastic pots filled with unsterilized sediment on May 5, 2012. A depth of 8cm was chosen as the maximum of continual burial according to the sedimentary rate (6–7cm) in the coastal marsh at seedling stage. Two weeks after emergence, seedlings were artificially buried to depths of 0 (D0, no burial), 33% (D33, burial of 1mmd−1), 67% (D67, burial of 2mmd−1), 100% (D100, burial of 3mmd−1) and 133% (D133, burial of 4mmd−1) of their mean height, with 20 days in total. Results showed that seedling height, stem and taproot diameter, number of branch, hypocotyl and taproot length, and dry mass were significantly affected by burial depth (p<0.05). No seedlings died in the four burial treatments. Seedling heights in the D33 and D67 treatments were higher than those of the other treatments, indicating that shallow and moderate burials exhibited greater stimulation to seedling growth. Although stem diameter, number and length of branch, and dry mass of seedlings were stimulated in the four burials, the greatest stimulatory effect on stem diameter was observed in the D100 treatment while that on number and length of branch and dry mass occurred in the D67 treatment. With increasing burial depth (D67, D100 and D133), seedling taproot diameter and length decreased while hypocotyl length increased, reflecting that hypocotyl elongation might occur at the expense of development of the root system. The responses of morphological traits and dry mass allocation of S. salsa seedlings to the burial treatments indicated that they might have a special strategy to tolerate the continual burial in the coastal marsh of the Yellow River estuary. The use of thin-layer burial (2mmd−1) to promote seedling vigor in degraded S. salsa marsh was feasible, and our study provided valuable information for the restoration of S. salsa marsh during seedling growth.

Condicionamento fisiológico e níveis de sombreamento em sementes de barbatimão (Stryphnodendron polyphyllum (Mart.) e S. adstringens (Mart.) Coville)

A dificuldade técnica devida à ocorrência de dormência das sementes é um entrave para a produção de mudas de espécies nativas em programas de recomposição de áreas degradadas do Cerrado. Objetivou-se com este trabalho avaliar o efeito do condicionamento fisiológico e do sombreamento na qualidade de sementes de duas espécies de barbatimão (Stryphnodendron polyphyllum e S. adstringens). Foram utilizados os seguintes tratamentos pré-germinativos: 1) PEG -1,0 MPa; 2) PEG -1,0 MPa+ KNO3 -1,0 MPa; 3) PEG -0,5 MPa; 4) PEG -0,5 MPa + KNO3 -0,5 MPa; 5) KNO3 -1,0 MPa; 6) Água deionizada; e 7) sementes que não receberam nenhum tratamento pré-germinativo (testemunha). Durante os tratamentos pré-germinativos, as sementes permaneceram incubadas em B.O.D. regulada na alternância de 20/30 ºC, durante 24 h, e em seguida semeadas em bandejas de células com Plantmax® mantidas em quatro níveis de sombreamento (pleno sol, 30%, 50% e 70%) com quatro repetições de 20 sementes. O condicionamento fisiológico com água de sementes de S. polyphyllum e S. adstringens e posterior semeadura em ambiente sombreado de 50 a 70% são eficientes para obter emergência rápida e elevada, maior altura e massa seca das plântulas. As sementes de S. polyphyllum podem ser osmocondicionadas com PEG 1,0 e PEG -0,5 MPA se a semeadura for realizada sob 30% de sombra. Entretanto, a semeadura de S. polyphyllum e S. adstringens não deve ser realizada a pleno sol.

Effect of GA3, KNO3, and removing of basal point of seeds on germination of sweet granadilla (Passiflora ligularis Juss) and yellow passion fruit (Passiflora edulis f. flavicarpa)

Passiflora seeds germinate erratically presenting difficulties for their handling in a greenhouse. The effect of removing of basal point of seeds (RB) and pre-imbibition of seeds of sweet granadilla and yellow passion fruit in 50, 100, 200, and 400 mg mL-1 solutions of gibberellic acid (GA3) or 0.1% KNO3 solution was studied. The experiment was conducted in greenhouses in La Plata, Colombia. Two accessions PrJ1 and PrJ2 of sweet granadilla were evaluated. There were calculated the final percentage of germination (PG), mean germination time (MGT), and the mean germination rate (MGR). The leaf area and dry mass of seedlings were measured 22 days after sowing (das); with this data, specific leaf area and relation root/shoot were calculated. In all cases, the highest germination percentages were achieved treating seeds with KNO3 (89, 92, and 87% for yellow passion fruit, PrJ2, and PrJ1, respectively), but the increase in MGR (3.3 germinated seeds per day) and the decrease in MGT (16 days) were only significant for PrJ1. RB had a significant reduction of PG in all cases (28, 12, and 33% for passion fruit, PrJ2 and PrJ1, respectively). With the increase in the concentration of GA3, PG was reduced for two accessions of sweet granadilla, for yellow passion fruit this trend was not clear, no treatment with GA3 showed significant differences with the control. Leaf area (24.07 cm2) and dry mass of seedlings (135 mg) were significantly higher than seeds previously treated with KNO3 only for PrJ1.The solution of KNO3 0,1% is recommended to improve the germination and initial growth of granadilla seedlings.

Temperaturas de secagem na integridade física, qualidade fisiológica e composição química de sementes de arroz

A secagem de sementes é uma operação indispensável no processo de produção, porém, a temperatura utilizada pode afetar a qualidade das sementes produzidas. Este trabalho objetivou avaliar o efeito de diferentes temperaturas de secagem na integridade física, qualidade fisiológica e composição química de sementes de arroz irrigado. Formaram-se quatro lotes de cada cultivar, os quais foram secos pelo método estacionário, utilizando-se as seguintes temperaturas: 32ºC, 38ºC, 44ºC e 50ºC. Após os tratamentos de secagem, avaliou-se a integridade física das sementes, por meio do teor de umidade e da percentagem de fissuras. A qualidade fisiológica foi determinada com o auxílio de teste de germinação, primeira contagem, condutividade elétrica, envelhecimento acelerado, teste de frio, comprimento total e fitomassa seca de plântula. A composição química das sementes foi avaliada por meio das frações massa seca, proteína e fibra bruta e extrato etéreo das sementes. As temperaturas de secagem afetaram a qualidade das sementes, e o aumento da temperatura, na secagem (32-50ºC), aumentou, também, a percentagem de fissuras nas sementes de arroz irrigado. As temperaturas de 32ºC e 38ºC, na secagem, permitiram a expressão da qualidade das sementes, enquanto a temperatura de 50ºC reduziu o seu potencial fisiológico.

Tolerância à dessecação em sementes de Bunchosia armenica (Cav.) DC.

The seeds have different behaviors and tolerance to moisture loss. In order to determine desiccation tolerance in seeds of Bunchosia armenia (Cav.) DC. (Ameixa-do-Pará) was collected a lot of fruits of this species in Areia-PB. After the manual pulping the seeds were exposed to dry on paper towel, under laboratory conditions (22°C and 85% RH) and greenhouse (24°C and 80% RH). Treatments consisted of sampling for the determination of water content and seedling emergence tests at baseline and after 24, 48, 72, 96 and 120 hours. The water content was measured by the oven method at 105 ± 3°C for 24 hours using four replicates of 10 seeds for each treatment. The seedling emergence test was conducted in a greenhouse with four replications of 25 seeds. The count of emergence has beenheld every two days, for a period of 35th day and calculated the IVE, length and dry mass of seedlings. The drying of the seeds of B.armenica, in both environments is viable for up to 24 hours; After 24 hours of drying the water content of seeds is reduced from 62.6% to 57%, a level considered critical to the desiccation of the seeds of Ameixa-do-Pará in both environments; Ameixa-do-Pará seeds nuts are dispersed with very high water content, and small reduction in physiological quality compromises their value, allowing the seeds to characterize this species as recalcitrant.

Germinação e vigor de sementes de Sapindus saponaria L. submetidas a tratamentos pré-germinativos, temperaturas e substratos

Sapindus saponaria L. é uma árvore de grande porte distribuída especialmente na região Amazônica, sendo de grande importância para o reflorestamento de áreas degradadas, na construção civil e confecção de brinquedos. O objetivo dessa pesquisa foi testar tratamentos pré-germinativos para superar a dormência e avaliar o efeito da temperatura e do substrato na germinação das sementes de S. saponaria. O experimento foi conduzido em ambiente protegido e no Laboratório de Análise de Sementes (LAS) da Universidade Federal da Paraíba. Dois ensaios foram desenvolvidos, sendo no primeiro testados os seguintes tratamentos: imersão das sementes em ácido sulfúrico (H2SO4) por 0, 15, 30, 45 e 60 minutos, analisando-se as variáveis: emergência e índice de velocidade de emergência, comprimento e massa seca de plântulas. No segundo ensaio foi avaliado o efeito das temperaturas (25, 20-30, 30 e 35°C) e substratos (areia, vermiculita e pó-de-coco) na germinação e no vigor das sementes. Pelos resultados constata-se que a imersão das sementes de S. saponaria em ácido sulfúrico por 60 minutos é suficiente para superar a dormência acelerando e uniformizando a emergência das plântulas. A melhor condição para executar o teste de germinação é empregando temperatura constante de 30°C ou alternada de 20-30°C em substrato vermiculita ou apenas 30°C combinado com o substrato areia.

RR soybean seed quality after application of glyphosate in different stages of crop development

In consequence of several studies and speculations concerning the issue of RR transgenic soybean after the application of glyphosate, additional scientific investigations became necessary to clarify the actual viability of the product use when applied in different developmental stages of the soybean crop. Therefore, this study was aimed to evaluate the physiological quality as well as seed health quality of RR soybean subjected to application of the herbicide glyphosate in different phonological stages of the transgenic soybean, cultivar CD 219RR. For this, an experiment with a complete block experimental design with treatments randomly distributed within the block, with four replications, was carried out. The assessed treatments were foliar sprayings of glyphosate in three increasing dosages [0 (control); 1,440 g ha-1; and 2,880 g ha-1] of acid equivalent, applied in two crop developmental stages: vegetative (V6) and reproductive (R2). The variables assessed were: germination; first count of germination; fresh and dry mass of seedlings, lengths of seedling and root; vigor and viability by the tetrazolium test; and seed health quality. Glyphosate application may adversely affect physiological quality of RR soybean seeds, when applied in dosages varying from 1,440 to 2,880 g acid equivalent per hectare at the stages V6 and R2.

Germinação e vigor de sementes de Myracrodruon urundeuva Allemão em diferentes substratos e temperaturas

Myracrodruon urundeuva Allemão é uma espécie pertencente à família Anacardiaceae, cuja planta pode ser medicinal, ser usada na indústria de curtimento de couro, na arborização de ruas e praças. Dessa forma, objetivou-se, com esta pesquisa, determinar metodologias adequadas para a condução de testes de germinação e vigor de sementes de M. urundeuva. Foram utilizadas as temperaturas de 25, 30 e 35 °C constante e 20-30 °C alternada, juntamente com os substratos areia, vermiculita, bioplant®, plantmax®, entre e sobre papel mata-borrão e papel-toalha, organizado na forma de rolo. O delineamento experimental foi inteiramente ao acaso, em quatro repetições de 25 sementes. Foram analisadas as seguintes características: porcentagem e velocidade de germinação, primeira contagem de germinação e comprimento e massa seca de plântulas. A temperatura de 30 °C e o substrato areia são indicados para a realização dos testes de germinação e vigor das sementes de M. urundeuva.

Germinação de sementes de Dalbergia nigra (Vell.) Fr. All.

Dalbergia nigra (Vell.) Fr. All., known popularly as jacaranda-da-bahia, it is a plentiful species known for the exploration of its wood. The experiment was conducted at the Laboratory of Seed Analysis (CCA/UFPB), in Areia, Paraiba State, with the objective of determining appropriate methodology for testing germination and vigor of D. nigra seeds. The experiment was carried out in an entirely randomized design in a 2 x 7 factorial scheme, with 2 temperatures (25 and 20-30oC) and 7 substrates (between sand, between vermiculite, Bioplant ® , Plantmax ® , between and on paper blotting paper, and towel paper), with four replications with 25 seeds each. The evaluated characteristics were: germination (%), first germination count (%), germination speed index (GSI), length and dry mass of seedlings. The best combinations for conducting germination and vigor tests with seeds of D. nigra were: temperature of 25°C and the substrate between vermiculite, on paper blotting paper and paper towel (roll); temperature of 20-30°C the substrate Bioplant ® and Plantmax ® .

Germinação e crescimento de Caesalpinia ferrea mart. Ex tul. Em diferentes substratos

A produção de mudas de espécies nativas para plantios comerciais e para recuperação de áreas degradadas faz com que haja grande procura por tecnologia que reduza os custos de estabelecimento dessas espécies, como substratos alternativos. Com o objetivo de proporcionar melhor emergência e crescimento inicial das plantas de Caesalpinia ferrea Mart. ex Tul., foram testados diferentes substratos, utilizando-se Latossolo Vermelho Distroférrico, textura argilosa - T, misturado com areia - A (0,5 dm³ de terra/ 0,5 dm³ de areia), acrescentando diferentes proporções de adubo orgânico organosuper® (AO) e adubo químico Yoorin® (AQ), constituindo os seguintes substratos: 1) T+A (testemunha); 2) T+A+AO (9,86 g dm-3 ); 3) T+A+AO (14,69 g dm-3 ); 4) T+A+AO (19,46 g dm-3 ), 5) A+T+AQ (8,4 g dm-3). A composição terra + areia + 19,46 g dm-3 do adubo orgânico proporcionou melhor emergência das plântulas e maior Índice de Velocidade de Emergência de pau-ferro, com valores de 60,4% e 0,330, respectivamente. A adubação química aumentou a produção de massa fresca e seca das plântulas, com valores de 399,9mg e 169,8mg, respectivamente, com médias que não variaram significativamente da maior dose de adubação orgânica. A adição de 19,46 g dm-3 de adubo orgânico Organosuper® proporcionou maior número de plântulas, em menor tempo e com plântulas mais vigorosas.

Achene buoyancy and germinability of the terrestrial invasive Fallopia × bohemica in aquatic environment: A new vector of dispersion?

Seed dispersal along watercourses can favour the long-distance migration of invasive species, not only for aquatic or wetland species, but also for terrestrial wind-dispersed plants. It is crucial to investigate the role of watercourses in the dispersal of the knotweed hybrid complex (Fallopia × bohemica) due to its frequent occurrence on riverbanks and production of fertile achenes. For this purpose, we experimentally studied buoyancy and germinability of F. × bohemica achenes in stirred water, over 28 d. We also measured the long-term survival and growth of seedlings according to exposure time to water. After nearly 2 d in the water, 50% of achenes were still afloat. After 3 d, germination occurred in water and the seedlings also floated. Moreover, the exposure of achenes to water, for however long, significantly favoured their germination rate, without affecting seedling survival, compared to a direct planting in soil. Furthermore, a maximum seedling dry mass was reached following exposure to water for 277 h (11.5 d), surpassing significantly the dry mass of seedlings planted directly in soil. Water exposure strongly favours achene germination and seedling survival. Our results demonstrate a high potential for the seeds and seedlings of Fallopia to be dispersed successfully by water.

Effect of temperature and substrate on germination of Peltophorum dubium (Sprengel) Taubert seeds

Peltophorum dubium (Spreng.) Taub. is a species belonging to the family Fabaceae, and is known popularly as golden shower tree. Its wood has multiple uses in reforestation programs and as an ornamental tree, and is also considered an endangered species, requiring studies that assist in its preservation. The present work was conducted with the objective of determine the ideal substrate type and temperature to perform germination and vigor tests with P. dubium seeds. The experiment was carried out at the Seed Analysis Laboratory (Centro de Ciencias Agrarias, Universidade Federal Paraiba, Areia, Paraiba, Brazil), in a completely randomized design. The treatments were distributed in a 4 x 6 factorial scheme; temperatures (constant temperatures of 25, 30 and 35°C; and alternate temperatures of 20- 30°C) and substrate (paper towel, over blotting paper, in sand, in vermiculite, Bioplant ® and Plantmax ® ) on four replications of 25 seeds. The following parameters were analyzed: germination percentage, germination speed index, first germination count, length and dry mass of seedlings. The constant temperature of 30°C and 20-30°C alternate, and the substrates into sand and paper towel can be recommended for germination and vigor tests of P. dubium seeds. The temperature of 25°C should not be used in germination and vigor tests of P. dubium seeds in any of the tested substrates.