Pre-germination Treatments Research Articles

Germination and morphology of seeds and seedlings of Colubrina glandulosa Perkins after overcoming dormancy

The objectives of the present study were to morphologically characterize the seeds, study post-seminal development, and report the best treatment to overcoming dormancy of colubrina (Colubrina glandulosa Perkins). Eight replicates of 100 seeds were weighed and the length, width, and thickness of each seed were measured for the physical characterization. External and internal aspects were considered for the morphological description of the seeds. Seven pre-germination treatments were used to overcoming dormancy: (T1) intact seeds; immersion in sulfuric acid for 60 (T2) and 90 min (T3); (T4) manual scarification in the region opposite the hilum; (T5) immersion in water at 80 degreesC, followed by standing in the same water outside the heat for 24 hours at room temperature; and immersion in distilled water for 24 (T6) and 48 hours (T7). The germinative process was recorded for 19 days in the post-seminal study. The variables analyzed were germination, first count, speed, average germination time, germination uncertainty and synchrony, seedling length, and dry mass. This was a completely randomized designed study, with four replicates of 25 seeds in each treatment. The seeds were morphologically highly variable. The testal and the embryo were the invaginated type. Germination was epigeal and the phanerocotyledonal type. Manual scarification induced maximum germinability in the mean time, resulting in a unimodal distribution of the relative frequency and high synchronization of germination, which allowed for the maximum number of highly vigorous seedlings. These results indicate a treatment for overcoming dormancy in C. glandulosa.

Pre-germination Treatments, Quality of Light and Temperature on Syagrus coronata (Mart.) Becc. Seeds Germination

Studies show that most species of palm trees present seed dormancy. This characteristic hinders the production of seedlings, due to the long period for germination and the unevenness of the seedlings. The specie Syagrus coronata, despite being widely used as food and economic resources, presents also seed dormancy, which hinders its propagation. Thus, this work aimed at evaluating the germination of S. coronata seeds using different methods of dormancy breaking and also, under different qualities of light and temperature. To do so, the seed endocarps were scarified by friction, puncture and complete removal of the endocarp, and the pre-soaking of seeds at different concentrations (50, 100, 200 and 400 mg L-1) of gibberellic acid (GA3) and indolebutyric acid (IBA). We also evaluated the effect of germination in seeds exposed to different conditions of light (white, red, far red, blue and dark) and to different temperatures (25, 30, 35 and 20-30 °C). The data show that the act of rubbing the endocarp optimizes the seed germination process. Solutions containing growth regulators in the pre-soaking of seeds have a negative impact on germination. And the absence of light and the constant temperature of 25 °C are the most suitable for germination. The results indicate that S. coronata seeds have physical dormancy, and, despite obtaining greater germination in the dark, they are neutral photoblastic.

Germinación de semillas silvestres de Apeiba glabra Aubl. (Malvaceae) y crecimiento inicial de plantas

El objetivo del presente trabajo fue evaluar la germinación de semillas silvestres, el crecimiento (en altura y diámetro) y la supervivencia de plantas de Apeiba glabra Aubl. El diseño experimental fue completamente aleatorizado con arreglo factorial y 16 factores, resultantes de combinaciones de sustratos y tratamientos pregerminativos. El experimento se desarrolló en dos camas de germinación previamente construidas bajo sombra y con exposición solar. La siembra incluyó 1.920 semillas, y el proceso de evaluación se realizó durante 75 días. La escarificación con lija y el remojo de las semillas en agua durante 48 horas incrementaron la germinación al 33% y el 34%. Estos valores aumentaron a más del 50% cuando se evaluó la interacción con el sustrato de tierra cernida y de arena + tierra cernida en una proporción de 2:1. Los resultados del crecimiento mostraron diferencias significativas entre factores y condiciones lumínicas, tanto en diámetro como en altura (p<0,05). El crecimiento y la supervivencia de las plántulas fueron mayores con los factores compuestos por tierra cernida (con y sin pregerminativos). En las condiciones de estudio, Apeiba glabra tiene una buena respuesta para su propagación con el uso de tierra cernida y escarificación con lija.

INFLUENCE OF PRE GERMINATION TREATMENTS ON OVERCOMING SEED DORMANCY AND SEEDLING GROWTH OF BAOBAB (Adansonia digitata L.)

There is an urgent need to overcome seed dormancy especially in some multi-benefit tree like baobab, which can be successfully cultivated in Southern Egypt, in order to improve their regeneration. Therefore, this study was carried out to investigate the effects of some pre-germination treatments i.e., soaking in tap water, boiling water or sulphuric acid at 98.5% for either 30 or 60 min, mechanical scarification with sandpaper alone or combined with soaking in sulphuric acid 98.5% for either 30 or 60 min, on germination characters and seedling traits of Adansonia digitata L. Results revealed that all pre-germination treatments significantly increased all germination parameters, growth performance and some chemical traits compared to the untreated seeds, except for soaking seeds in tap water. The descending order of pre-sowing treatments was scratching baobab seeds then soaking in sulphuric acid 98.5% for 60 or 30 min ˃ soaking in sulphuric acid 98.5% for 60 or 30 min˃ mechanical scarification with sandpaper ˃ boiling water. In the same order was minimized number of days from sowing until the emergence of the plumule from 68 to 6 days and increasing germination (%) from 9 to 94% for untreated and soaking in tap water without significant differences in between and scratching seeds then soaking in sulphuric acid 98.5% for 60 min, respectively. There were increments in seedling height (from 4.27 to 57.58%) and in stem diameter (from 21.67 to 61.48%) for seeds soaked in tap water, and scratching seeds then soaking in sulphuric acid 98.5% for 60 min, respectively. Generally, all previous treatments except soaking in tap water led to breaking baobab seed dormancy. The best treatment was scratching seeds before soaking in sulphuric acid 98.5% for 30 mints.

Evaluation of different pre-germinative methods for three tree species of the Fabaceae family in different environments

The Sesbania virgata (Cav.) Pers., Mimosa caesalpiniifolia Benth. and Cassia grandis L.f. species belong to the Fabaceae family, are characterized by their seeds present a dormant state, which limits the germination. The aim of this study was to evaluate the efficiency of pre-germination treatments to overcome dormancy these species. Seeds were collected from matrix trees, located in Agreste of Alagoas and the research developed at the Federal University of Alagoas – Campus de Arapiraca. Overcoming of dormancy was studied in laboratory and greenhouse, where they were employed eight treatments with four replications of 25 seeds, in a completely randomized design: immersion in sulfuric acid (in three periods of immersion, depending on species), scarification with sandpaper, immersion in hot water at 80 °C (2.5 and 5 minutes), imbibition for 24 hours in distilled water and control (seeds without the application of any treatment). The evaluation of the results was made through of germination and emergence percentage; germination and emergence speed index and germination and emergence average time. The pre-germination treatments, mechanical scarification with sandpaper and chemical scarification with sulfuric acid in different immersion times were the most efficient to overcome the seeds dormancy of Sesbania virgata , Mimosa caesalpiniifolia and Cassia grandis Independent of the studied environments.

Pre-germination treatments on Senna arnottiana and Senna kurtzii: key contributions for restoration initiatives in Payunia, Patagonia, Argentina

In arid and semi-arid ecosystems, increasing and irreversible degradation in areas of high conservation value has prompted the search for various solutions, such as rehabilitation and ecological restoration. To implement these strategies, it is essential to solve critical issues affecting the establishment of plants in the field and the production of seedlings in nursery gardens. In the present work, the following pre-germination treatments were evaluated for the species <i>Senna arnottiana</i> and <i>S. kurtzii</i>, endemic to the Patagonian steppe (Payunia): (1) Immersion in water at 80 °C for 5 minutes; (2) Immersion in water at 80 °C for 10 minutes; (3) Immersion in water at 100 °C for 5 minutes; (4) Immersion in water at 100 °C for 10 minutes; (5) Acid scarification with sulfuric acid for 30 minutes; (6) Acid scarification with sulfuric acid for 60 minutes; (7) Soaking in water at 80 °C until cooled for 24 hours, and (8) Control (no treatment). For both species, the highest, fastest, and most homogeneous germination was obtained with acid scarification, i.e., 70% germination for <i>S. arnottiana</i> and 95% germination for <i>S. kurtzii</i>. Although this method requires the use of a laboratory and has a high economic cost for local residents, the high germination percentages obtained make it highly recommended for the production of large quantities of seedlings.

Pre-germination treatment and different temperatures conditions on Echinacea purpurea seed germination

Echinacea purpurea (L) Moench, is a medicinal and herbaceous plant from Asteraceae family, and has an important role on economics of many communities. Germination is one of the main steps on understanding this specie. Thus, the aim of this study was to evaluate the effect of temperature conditions and precooling treatment on E. purpurea seed germination. This study was conducted on completely randomized design, with four repetitions and tree treatments, constituted by three germination temperatures (20°C, 30°C and 20-30°C) and two treatments, which is, breaking dormancy by precooling (5 oC) for seven days and the control sample without precooling. Gerbox was used for germination test. The germination was determined by primary root protrusion. As result, germinations were satisfactory on three temperatures at the two groups. The highest germination potential was observed in alternating temperature 20-30°C (97.00 ± 0.93%). Better germinations percentages were observed in precooling treatment (97.75 ± 0.62%) and in the treatment without precooling (95.58 ±0.54%). Temperature directly impacts coefficient of velocity of germination (CVG), with no statistical difference in the group subjected to precooling for temperatures of 20-30°C and in constant temperature of 30oC. However, on the group without precooling treatment, the alternating temperature gets better CVG. To mean germination time (MGT), temperature of 20-30°C get better result (2.92 ± 0.13). E. purpurea presents fast germination in less than five days.

Reproductive Phenology and Seed Germination in Eight Tree Species From a Seasonally Dry Tropical Forest of Morelos, Mexico: Implications for Community-Oriented Restoration and Conservation

With the aim of providing information for ecological restoration programs, we studied reproductive phenology and seed germination of eight species from the tropical dry forest of Morelos, Mexico. With the participation of students from the local junior high school, we monitored monthly, over one year, the production of flowers and immature and mature fruits for each species. We estimated intensity, duration, seasonality, and synchrony for each fruiting phenophase and flowering duration. Germination tests were undertaken in a germination chamber (18℃–32℃) and under the environmental conditions at the local school. We applied specific pregermination treatments for each species. Two distinct peaks of mature fruit production were identified: one at the beginning and the other in the middle of the dry season. Fructification seasonality was significant in most cases. Germination was relatively high in three legumes and particularly low in two Bursera species. Four species responded to the germination environments, and differences among pregermination treatments were significant in most cases. Knowledge on fruiting patterns and seed viability and germination will allow adequate decision-making for seed collection and plant propagation of the study species. Student participation increased their interest and knowledge on local environmental problems and solutions.

Seed Priming Effects on Germination and Seedling Establishment of Useful Tropical Trees for Ecological Restoration

We assessed the effects of seed priming and soil retainers on seed germination and early seedling performance of useful species in a tropical semideciduous forest in Veracruz, México. We determined mass and water and lipid content in the seeds of Albizia saman, Cedrela odorata, Enterolobium cyclocarpum, and Swietenia macrophylla. The seeds were exposed to hydropriming and natural priming (seed burial inside the soil) and germinated at 25°C and 25/35°C. The produced seedlings were grown in a shade house and planted in a plain terrain and a hillside (slope 75%). Seedling growth and survival were evaluated. S. macrophylla and E. cyclocarpum seeds had the lowest and highest water content, respectively. S. macrophylla and C. odorata had oil seeds. A. saman and E. cyclocarpum seeds had physical dormancy. Natural priming improved germination in A. saman, C. odorata, and S. macrophylla while hydropriming and 25/35°C enhanced germination in E. cyclocarpum. In the shade house, natural priming promoted seedling growth in all studied species and in the field survival of A. saman and S. macrophylla. In E. cyclocarpum, this effect was obtained with hydropriming in the plain terrain. In the hillside, hydropriming and natural priming and 25/35°C improved survival of S. macrophylla and E. cyclocarpum, respectively. Seed burial for 8 days improved germination, seedling performance, and survival. To bury seeds inside a pot placed in a shade house induced natural priming in C. odorata. We suggest natural priming for A. saman, C. odorata, and S. macrophylla, and hydropriming for E. cyclocarpum seeds. Germination pretreatments were inexpensive and easy tools potentially applicable in restoration and conservation programs.

The effects of pre-germination treatments and soil media on seed germination and seedling growth of Tamarind (Tamarindus indica (Linn) in Katsina State, Nigeria

Astudy was conducted to investigate theeffects of pre-germination treatments andsoil media on seed germination andseedling growth of Tamarind (Tamarindusindica) in Katsina State, Nigeria.Germination was monitored in the NurserySection of the Federal University Dutsin-Ma, Katsina State, Nigeria. The experimentwas laid in a Completely RandomizedDesign with four replications. Seedlingheight (SH), stem diameter (SD) andnumber of branches (NB) were measuredat two week intervals and analyzed usingAnalysis of Variance. Means wereseparated using Least SignificantDifference (LSD P≤0.05). Mechanicallyscarified seeds (MS), sown in top soil (S1)(S1MS) and seeds treated with 60 %concentrated Tetraoxosulphate (VI) acid(H2SO4) for 10 minutes (A10) and sown inS1 (S1A10), MS sown in S2 (S2MS), seedstreated with A10 and sown in S2 (S2A10),MS sown in top soil plus river sand plusmanure (S3) (S3MS) and seeds treated withA10 and sown in S3 (S3A10) germinated infirst five days after sowing (DAS) whilethose in the control germinated after ninedays. Treatment with A10 resulted in 100 %germination while MS resulted in 97.5 %germination. MS and seeds soaked inH2SO4 for five (5) minutes (A5) had higherSH values of 8.30 cm and 30.81 cmrespectively and NB values of 2.92. A10and MS had SD values of 3.20 cm and 3.20cm respectively. It is concluded that seedstreated with H2SO4 for 10 minutes and MSat the micropyle are the best pregerminationtreatment for breaking T.indica seeds and recommended for seedsowers so in order to achieve regenerationthat can meet various needs of man.

Dormición física en Lepechinia floribunda (Lamiaceae): Un arbusto nativo de interés medicinal

Lepechinia floribunda es un arbusto aromático medicinal que tiene múltiples aplicaciones. La baja germinación de sus semillas es el principal rasgo que hasta el momento ha limitado su propagación. El objetivo del presente trabajo fue determinar la presencia de dormición física en semillas de L. floribunda y evaluar la eficiencia de distintos pretratamientos y el tiempo de almacenamiento en romper dicha dormición. Se realizó un experimento de imbibición y otros de germinación con semillas almacenadas por 0, 90, 270 y 1050 días utilizando escarificación térmica (con agua a 100°C) y química (ácido sulfúrico concentrado) como pretratamientos. Las semillas de L. floribunda presentaron dormición física y el tratamiento más efectivo para romper la dormición fue el ácido sulfúrico, con valores que superan el 70% de germinación. El tiempo de almacenamiento no afectó el estado de dormición y la viabilidad de las semillas se mantuvo alta durante 3 años. Estos resultados ayudarán a establecer estrategias de propagación sexual para esta especie nativa de gran interés aplicado.

Ultra-high pressure effects on color, volatile organic compounds and antioxidants of wholegrain brown rice (Oryza sativa L.) during storage: A comparative study with high-intensity ultrasound and germination pretreatments

Abstract Wholegrain brown rice (WBR) with significantly enhanced quality attributes has been recently achieved after ultra-high pressure (UHP) processing, but the process-induced changes in physicochemical parameters following subsequent storage for UHP-treated WBR are scarcely documented. So this work was designed to investigate the effects of UHP treatments (0.1–450 MPa/10 min) on chemical composition, microstructure, and the changes in chemical reactions during storage (20 days/30 °C) as indicated by volatile profiling, color development, and antioxidant activities for WBR grains, compared to high-intensity ultrasound (HIU) and germination (GER) pretreatments. Results showed that significant variation in physicochemical properties was caused by both processing approaches and storage duration. Color changes (a*, b*, L*, and ΔE) were slightly noticeable after storage for all WBR samples, and UHP-treated grains represented clearly visible browning reactions. In addition, hierarchically clustered heatmap suggested that volatile fingerprinting could be preliminarily separated according to different pretreatments and storage duration. After immediate treatments, total antioxidant activities presented a decrease by 14–28% for all treated grains compared to the unprocessed samples. Within storage process, GER and HIU samples showed steadily declining trends for antioxidant activities whereas a fluctuation was observed in UHP-treated grains. Besides, samples treated by 350/450 MPa maintained more antioxidants (91–102%) than the control (83–87%), GER (64–76%) and HIU (76–88%) samples at the end of storage. Multivariate analysis revealed a close relationship between color changes and antioxidant activity. These results indicated the necessity of a complete evaluation for possible processing effects on physicochemical and nutritional characteristics of WBR grains within the entire process extending immediate treatments to its prolonged storage and consumption, in order to achieve better quality control using the optimized processing parameters. Industrial relevance The selected emerging techniques including UHP, HIU and GER allow the acquisition of WBR products with improved texture and cooking properties as well as the enrichment of bioactive components. Nevertheless, the processed WBR grains must be subjected to a storage process before consumption. A more comprehensive understanding of the effects of newly-developed techniques on quality characteristics of WBR grains contributes to better control of products quality, particularly extending from immediate effects to the prolonged storage.

Evaluation of the effects of temperature and time of soaking in the speed of germination in Malagueta peppers

Peppers are indispensable ingredients in the national cuisine, besides being consumed fresh, can be processed and used in several lines of products in the food industry. Pre-germination treatments of vegetable seeds reduce the time between sowing and emergence of seedlings and increase seed tolerance to adverse environmental conditions. The objective of this work was to evaluate the effect of different imbibition times, and different water temperatures, on the quality and speed of germination in chilli pepper seeds. The seeds were submitted to soaking in water previously heated at 30 °C, 60 °C and 90 °C for 15 seconds, 30 seconds and 60 seconds, and then placed in a gerbox with moist germ paper. The gerboxes were kept in greenhouse with luminosity and constant temperature of 23 °C. The design was completely randomized with 10 treatments (3 soaking times x 3 water temperatures + 1 control) and three replications. The seeds were evaluated daily after germination. The temperature of 90 ° C proved to be detrimental to the germination of the seeds, while the other temperatures showed no significant difference. It was concluded that the temperature of 90 ° C may have caused death of the embryo.

Métodos de escarificación en semillas de Guaiacum coulteri , especie amenazada del bosque tropical caducifolio del norte de Sinaloa, México

This investigation documented the effect of methods of physical and chemical scarifi cation in seeds of Guaiacum coulteri, a species of tropical deciduous forest from Sinaloa protected by national and international laws, in order to contribute to the germinative knowledge of the species. For this, six pregerminative treatments were evaluated on the initial germination time (IGT), initial germination percentage (IGP), mean germination time (t50) and fi nal germination percentage (FGP) with a randomized completely design under laboratory conditions. Scarifi cation methods infl uenced signifi cantly (p<0.05) in the four variables. The seeds subjected to the treatments H2SO4 for 5 and 10 min started to germinate one day after sowing, whereas in the control occurred until the third day. The initial germination percentage increased to 73.3% with the treatment of sandpaper against the control that was just 10%. The scarifi cation with H2SO4 for 5 and 10 min advanced the mean germination time to 1.8 d, in relation with the control that was 5.2 d. The higher fi nal germination percentage was obtained with the sanding of the seeds (86.7%), unlike 51.1% achieved in hot water (60 °C) for 10 min. The knowledge derived from this essay demonstrated that the methods of scarifi cation with sandpaper and sulfuric acid were the best pregerminative treatments, due to they fragmented or weakened the seed coat and allowed obtaining high germination rates, what will have relevance for the production of seedlings.

Reproducción asexual, sexual y vigor en semillas de caracolí Anacardium excelsum (Bertero ex Kunth) Skeels en el departamento de Sucre

El bosque seco tropical en Colombia se encuentra en disminución y deforestación constante de su cobertura, Anacardium excelsum es un representante en este tipo de bosque, sin embargo se encuentra casi amenazada a nivel nacional. Teniendo en cuenta este aspecto y su importancia como especie maderable, el objetivo de la investigación fue hallar la mejor forma de reproducción, sexual o asexual, y determinar el vigor y el mejor tratamiento pre-germinativo para romper la latencia de las semillas. Se realizaron siete tratamientos pre-germinativos y tres con solución de hormona para enraizamiento de estacas. La escarificación con bisturí e inmersión en HCl por 5 minutos presentaron un mayor porcentaje de germinación, la mayor parte de las plantas germinaron antes de los 4 días de haber sido sembradas, y presentaron una tasa de crecimiento entre 3 y 4 cm por día en la primera semana. Con respecto a la reproducción asexual, en ninguna de las estacas se obtuvo formación de raíces y yemas. La reproducción sexual resultó ser el mejor método, y el tratamiento pre-germinativo de escarificación con bisturí fue el que presento mayor porcentaje de germinación.

Slow imbibition of Annona emarginata (Annonaceae) seeds: metabolic and ultrastructural evaluations

Germination pattern may be affected when seeds are dispersed under flooded conditions or subjected to pre-germination treatments such as immersion in plant growth regulators and priming. We evaluated the metabolic and ultrastructural changes in the seeds of Annona emarginata (Schltdl.) H. Rainer seeds caused by immersion in water (0 MPa) during the imbibition phase (phase I). The immersion time necessary for initially dry seeds (10% water content) to reach a water content of 15%, 20%, and 35% was recorded. The seeds were also immersed in a polyethylene glycol 6000 solution (–1.2 MPa) to decrease the rate of water uptake and increase the immersion times required for the seeds to reach the selected water contents. With shorter immersion times, seed damage did not decrease germinability. Seeds immersed for 122 h sustained damage to the cell membrane system and organelles, resulting in a decreased percentage and rate of germination. Decreasing the rate of water uptake increased the time required to finish imbibition phase to 317 h and resulted in more ultrastructural damages and a decreased germination index. We conclude that in seeds with slower imbibition, longer immersion times may cause severe metabolic damage if the seeds are immersed until the end of the imbibition phase, resulting in reduced germination.

English

This study evaluated the presence of integument dormancy in Melanoxylon brauna seeds by testing the influence of nine pre-germination treatments on seed germination compared to a control (no pre-germination) treatment. Pre-germination treatments include; immersion in sulfuric acid for 5 min, 10 min, 15 min and 30 min, hot water at 80°C without soaking, hot water at 80°C with soaking for 30 min, 90 min, 24 h, and mechanical scarification. The experiment consisted of a completely randomized design, with four replicates and 25 seeds per experimental unit. Percentage germination, germination speed, number of normal and abnormal seedlings, and mortality rate were evaluated. Seeds began to germinate at four days, and germination varied from 33 to 89%, with the highest percentage found in hot water with or without soaking for 30 min, which not differed statiscally from control. Immersion in sulfuric acid for longer than 10 min reduced seed germination and increased mortality rate. We conclude that M. brauna seeds do not undergo seed dormancy, and there is no need to apply pre-germinating treatments to its seeds. Key words: Dormancy, seed technology, Leguminosae.

Comparison of pre-germination treatments in Lupinus spp. and their effects on germination and related solutes

Background. Physical dormancy in seeds of the genus Lupinus restricts their ecological or agricultural use.&#x0D; Hypothesis. This dormancy can be broken when seeds are subjected to physical and chemical pretreatments that increase germination, mobilize reserves and decrease ABA.&#x0D; Studied species. Seeds of Lupinus exaltatus ( Le ), L. campestris ( Lc ) and L. montanus ( Lm ) from Puebla, México.&#x0D; Methods. The following seven treatments, including a control, were applied: PG1 = 98 % H2SO4 for 15 min, PG2 = wet sand at 80 °C for 5 min, PG3 = wet sand at 35 °C for 8 h and 16 h at 25 °C, PG4 = dry sand at 80 °C for 7 min, PG5 = dry sand at 150 °C for 1 min, PG6 = H20 at 80 °C for 1 min, Control = untreated seeds. On days 0, 3, 5, 10 and 15 after seeding, we evaluated the percentage and rate of germination (GP and GR, respectively) and biochemical changes.&#x0D; Results. PG6 produced a higher GP in Le (41 %) and Lc (69 %), and PG1 produced a higher GP in Lm (37 %). In all three species, the highest GR was obtained with PG1 (1.95, 2.27 and 2.22 day-1 seeds, respectively). PG6 increased the protein concentration (53, 17, and 43 % for Le , Lc and Lm , respectively), amino acids (19, 44 and 31 %, respectively), reducing sugars (63, 18 and 96 %, respectively) and polyphenols (32, 55 and 75 %, respectively) but decreased soluble sugars (22, 29 and 23 %, respectively) and ABA relative to the control. Although only the correlation between the GP and amino acid content was significant and positive, and the correlation between GP, GR and soluble sugars was significant and negative.&#x0D; Conclusions. The effect of pre-germination treatments on germination was species-specific. The pretreatment with H20 at 80 °C for 1 min increased germination and mobilized the seed’s reserves in the process.

Métodos para superação da dormência tegumentar em sementes de Caesalpinia ferrea Mart. ex Tul.

O presente trabalho teve por objetivo avaliar a eficiência de métodos para superação de dormência tegumentar em sementes de &lt;em&gt;Caesalpinia ferrea&lt;/em&gt;. O delineamento experimental utilizado foi o inteiramente casualizado, com doze tratamentos e quatro repetições de 25 sementes por unidade experimental. Os tratamentos pré-germinativos utilizados foram: testemunha (T1); imersão em água a 100, 80 e 65 °C por 5 minutos (T2, T3 e T4, respectivamente); imersão em ácido sulfúrico (98%) por 5 e 10 minutos (T5 e T6, respectivamente); escarificação em lixa n° 120 (T7); desponte na região oposta ao hilo e na extremidade do ponto de inserção da vagem (T8 e T9, respectivamente); imersão em vinagre de álcool, de vinho tinto e vinho branco, por 15 minutos (T10, T11 e T12, respectivamente). As características avaliadas foram: percentagem de emergência, índice de velocidade de emergência, percentagem de sementes duras e mortas, comprimento de raiz, altura de plântulas e número de folhas. Os tratamentos com a imersão em ácido sulfúrico por 5 ou 10 minutos, escarificação com lixa n° 120 e o desponte do tegumento, tanto na região oposta ao hilo quanto na extremidade do ponto de inserção da vagem, são os mais adequados para a superação de dormência tegumentar nas sementes de &lt;em&gt;Caesalpinia ferrea&lt;/em&gt;.

Germinación, diámetro de semilla y tratamientos pregerminativos en especies con diferentes finalidades de uso

The evaluation of vegetal species germination consents to know its characteristics and permits to understand the factors that influence this process. The aim of this research was to know the germination’s characteristics of some species, such as Eugenia stipitata McVaugh, Inga edulis Mart, Inga spectabilis (Vahl) Wild, Piptocoma discolor (Kunth) Pruski, Stachytarpheta cayennensis (Rich.) Vahl, and Verbena officinalis L., and also their reaction to pregerminative treatments depending on the seed’s diameter. This study was carried out in Pastaza, Province of Pastaza, Ecuador, between February and June, 2014. Different diameters of seeds and pregerminative treatments were used in species, which did not present germination percentages higher than 40%. In the first practice I. edulis and I. spectabilis exceeded this value without treatment. Other species had lower values. Seeds were classified considering two diameters and two doses of gibberellin acid, this was applied to, and evaluated in the E. stipitata. In addition, scarification with sulfuric acid was done. After 45 days of its application, 100 ppm of gibberellic acid with larger seed diameter reported higher percentages of germination in S. cayenennsis, and in E. stipitata, which also interacted with the scarification. V. officinalis and P. discolor, did not present any response to the applications made. I. edulis and I. spectabilis presented high germination percentages without pregerminative treatments, E. stipitata and S. cayenennsis showed response to seed diameter and the applied treatments, while P discolor and V. officinalis did not show any response.