scholarly journals Efeito da temperatura e do substrato na germinação de Hamatocactus setispinus (Cactaceae)

2015 ◽  
Vol 21 (2) ◽  
pp. 173
Author(s):  
Priscilla Brites Xavier ◽  
Janie Mendes Jasmim

Cacti are widely used as ornamental plants and seed germination is a major method for preserving genetic diversity. Thus, an experiment was carried out to evaluate the effects of different temperatures and substrates on seed germination of Hamatocactus setispinus. Seeds were sown in gerbox boxes containing either germination paper (S1), sand (S2) or vermiculite (S3). After placing the seeds on the substrates, the boxes were kept in germination chambers at 20, 25, 30 and 35° C for 30 days, under a photoperiod of 16 hours. The experiment was in a completely randomized design with four replicates. The speed germination index (SGI), mean germination time (MT) and germination rates (%) were evaluated. The best results were observed at 25º C. The highest SGI (3.94) was observed on seed germination paper, but MT values and germination rates on this substrate did not differ from those obtained on sand. Therefore, both substrates could be used for germination of this cactus species.

2018 ◽  
Vol 36 (0) ◽  
Author(s):  
J.M.L. AZEVEDO ◽  
C.G.G. SANTOS ◽  
C.S. CAIRES ◽  
J.C. ARAÚJO NETO ◽  
R.C. SOUZA

ABSTRACT: The goal of this work was to characterize morphometrically diaspores from three species of mistletoes (Passovia pyrifolia, Struthanthus marginatus e Phoradendron mucronatum), as well as to study its germination behavior according to temperature and luminosity. In germination tests, the completely randomized design was used, in factor scheme 4 x 2, with 4 replications of 15 diaspores. The factors for the first test were different temperatures and two diaspore conditions (intact and without epicarp). In the second test, factors were different light qualities and two diaspore conditions. The analyzed variables were: germination percentage, germination rate index (GRI) and mean germination time (MGT). Mistletoe’s diaspores present an elliptic shape with viscin layer, an essential characteristic for the dispersion of the species. In addition to this, they present a distinction as for the moisture content when compared to the Loranthaceae and Viscaceae, where the latter presents the highest content. Germination is greater at the alternated temperature of 20-30 oC for P. pyrifolia and P. mucronatum diaspores and 20 oC for S. marginatus. Luminosity interfered in the germination of P. mucronatum and S. marginatus but did not influence P. pyrifolia. The diaspore condition influenced the germination of the three studied species, observing a significant increase in their germination when the epicarp was removed. Temperature and luminosity interfere directly in the GRI and MGT of the three mistletoes species.


FLORESTA ◽  
2019 ◽  
Vol 50 (1) ◽  
pp. 923
Author(s):  
Ademir Kleber Morbeck Oliveira ◽  
Jose Carlos Pina

Germination is considered a critical step in the seedling production process aiming the recovery of environments. Thus, understanding the germination behavior of native species with potential for economic use contributes to the development of the forest seed and seedling chain. Considering the limited information on the tree species Pouteria torta subesp. torta, this study aimed to evaluate its seed germination and formation of normal seedlings using different temperatures and substrates. The experiment was conducted in germination chamber in a research laboratory using two substrates (paper and vermiculite) and six temperatures (20, 25, 30, 35, 20-30 and 25-35 °C) in a completely randomized design in a 2x6 factorial arrangement. Daily evaluation was conducted to verify primary root emission, seed vigor, and seedling formation. The results indicated that the primary root protrusion process began after 20 days of testing under the best conditions, with germination time lasting longer than two months. The results obtained also showed that there was interaction between factors, with use of the vermiculite substrate and the temperatures of 35 and 25-35 °C producing the best germination rates and germination speed index, and use of the paper substrate and the temperatures of 30 and 35 °C showing the best mean germination time. Considering the analyzed variables (germination, germination speed index, and formation of normal seedlings), the temperatures of 35 and 25-35 °C and the vermiculite substrate are the most suitable for the production of Pouteria torta subesp. torta seedlings.


2021 ◽  
Vol 12 (2) ◽  
pp. 51-66
Author(s):  
Luciana Pinto Paim ◽  
Eduarda Demari Avrella ◽  
Juliana Carolina Alves Horlle ◽  
Claudimar Sidnei Fior ◽  
Marília Lazarotto ◽  
...  

Contextualization: Lupinus bracteolaris is a heliophite species that vegetates low lands, open slopes and sandstone hills. Knowledge gap: Despite the high rusticity and potential for covering poor soils, there is still no information to assist in the analysis of its seeds. Purpose: To determine pre-germinative treatments, substrate, temperature, luminosity and water intake in the vigor of Lupinus bracteolaris seeds. Methodology: Fruits were collected from 20 matrix plants, then the seeds were processed and submitted to the following tests: pre-germinative 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: According to the analyzed variables, the results showed superiority 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 seed germination. The seeds of Lupinus bracteolaris were classified as neutral-photoblastic and without dormancy.


2019 ◽  
Vol 32 (2) ◽  
pp. 411-418
Author(s):  
CLAUDIA KELY PIRES DE MATTOS SORANA ◽  
CARLOS HENRIQUE QUEIROZ REGO ◽  
FERNANDA BRITO CARDOSO ◽  
TIAGO ROQUE BENETOLI DA SILVA ◽  
ANA CARINA DA SILVA CÂNDIDO ◽  
...  

ABSTRACT The aim of the present study was to evaluate the effects of temperature, substrate, and luminosity on chia seeds in order to determine adequate conditions for a germination test. The experiment consisted of a completely randomized design, in a 4 × 5 × 2 factorial scheme (four substrates × five temperatures × two luminosity conditions), with four replications. The following variables were analyzed: first germination count, germination, germination speed index, and mean germination time. Germination was best at 15, 20, 25, and 30 °C for the on-paper, paper roll, and sand substrates. However, in the presence of luminosity and at 25 °C, the on-paper substrate had the highest mean. For all substrates, the lowest germination was achieved at 35 °C, proving that high temperatures reduce chia seed germination. Germination speed index was highest at 25 and 30 °C for on-paper, paper roll, and sand substrates, in both the presence and absence of luminosity. Chia seeds are considered to be neutral photoblasts. Germination tests should be performed with the on-paper substrate, at 25 °C, and with a duration of seven days. The first count should be carried out four days after establishment of the test.


2021 ◽  
Vol 42 (5) ◽  
pp. 2639-2650
Author(s):  
Verônica Pellizzaro Moresco ◽  
◽  
Mônica Satie Omura ◽  
Jean Carlo Baudraz de Paula ◽  
Felipe Favoretto Furlan ◽  
...  

Bromeliads have been gaining ground in the economic scenario due mainly to their use as ornamental plants. Bromeliads of the genus Dyckia exhibit different morphologies, and therefore, have relevance in this market. However, some species are threatened due to the extraction of plants from their natural environments. Many of these species are endemic and native to Brazil and there are few studies on their seed physiology; hence, expansion of research into this topic is essential. An alternative for the preservation of such plants is the production of seedlings using seeds. To this end, the objective of this work was to evaluate the physiological potential of seeds of Dyckia brevifolia, Dyckia beateae, and Dyckia excelsa at different temperatures, and determine the number of days to carry out the tests. A completely randomized design was adopted, with three species of Dyckia, analyzed separately, and four temperatures (20, 25, 30, and 35 °C). The following were evaluated: first germination count, germination, germination speed index, length of seedling, and seedling dry weight. The data were analyzed using the Sisvar software for normality and homogeneity, and when the assumptions were met, they were subjected to analysis of variance using the F test (p < 0.05) and the means were compared using the Tukey test at 5% probability. Seeds of D. excelsa emit the radicle more quickly at 20 and 35 °C; however, temperatures of 25 and 30 °C provide better conditions for seedling growth and development. The greatest vigor of D. brevifolia seeds is observed at temperatures of 30 and 35 °C. Seeds of D. beateae emit the radicle more quickly at 20 °C, and the largest seedlings are observed at 35 °C. The first germination count of D. brevifolia, D. beateae, and D. excelsa should be evaluated on the third day after sowing. The germination evaluations for D. excelsa and D. beateae should be carried out on the ninth day after sowing, and those for D. brevifolia on the sixth day after sowing.


2017 ◽  
Vol 17 (1) ◽  
pp. 83-90
Author(s):  
D. O. ADELANI ◽  
R. A. SULEIMAN ◽  
U. U. EMEGHARA

Diospyros mespiliformis (Hochst) is a multipurpose, agro-forestry tree species with diverse environmental and ecological significances. However, low percentage germination associated with its seeds has limited its domestication. To overcome this challenge, there is need to adopt cheap, fast, safe, natural and adoptable physiological techniques such as sand priming and hydro-priming. There is paucity of quantified information on natural and safe methods of relieving dormancy as sand priming and hydro-priming. Most of methods of breaking dormancy as use of acid are not simple, safe and adoptable by farmers who practices agro-forestry. In the light of this, these experiments were conducted to assess the periods of sand priming (0, 2, 4, 6 and 8 weeks) and hydro-priming (0, 2, 4, 6 and 8 weeks) on the germination of D. mespiliformis. Both experiments were laid down in completely randomized design with four replicates. Mean germination times were calculated, and result revealed that a significant increase in percentage germination was recorded with increasing periods of exposing seeds to sand priming up to four weeks. The percentage germination ranged between 28%-93.25% for control (0) and four weeks sand priming respectively. Least value of 8.92 day was recorded for mean germination time of control (0 sand priming). A significant increase in percentage germination was recorded with increasing hours of hydro-priming up to 24 hours. The percentage germination was ranged between 25% - 100% for control (0) hour to 24 hours. Highest germination percentages were recorded in seeds subjected to sand priming for 4weeks (93.25%) and those hydro-primed for 24hours (100%). These results are recommended for mass production of D. mespiliformis in agro-forestry nurseries.  


Author(s):  
Sofia ARGYRIOU ◽  
Panayiota PAPASTYLIANOU ◽  
George STAVROPOULOS ◽  
Angeliki KOUSTA ◽  
Ioanna KAKABOUKI ◽  
...  

Helichrysum amorginum is a perennial shrub, endemic on the Greek island of Amorgos and used for medicinal, cosmetic and ornamental purposes. Information concerning germination behavior and seedling survival is considered essential for the establishment and cultivation of wild species. The objective of this study was to investigate the effect of temperature and light on germination of Helichrysum amorginum seeds. A set of experiments was conducted under completely randomized design with four replications of 200 seeds at three different suboptimal germination temperatures (15, 20 and 25°C) in light and dark conditions for 10 days. Seed material was collected from two different fields of the island (Aegiali and Katapola). The germination performance was evaluated by final germination percentage and mean germination time. The effect of temperature on seed germination percentage and mean germination time was significant in all cases. The presence of light enhanced germination, especially at the optimum temperature of 20°C. In most cases the mean germination time increased at the lower temperature of 15°C. Seeds from Aegiali exhibited higher germination ability than the seed lot from Katapola. Knowledge of seed germination behaviour is of major importance in order to establish effective protocols for seed propagation in Helichrysum amorginum.


2013 ◽  
Vol 31 (1) ◽  
pp. 39-51 ◽  
Author(s):  
A Tanveer ◽  
M Tasneem ◽  
A Khaliq ◽  
M.M Javaid ◽  
M.N Chaudhry

An understanding of seed germination ecology of weeds can assist in predicting their potential distribution and developing effective management strategies. Influence of environmental factors and seed size on germination and seedling emergence of Convolvulus arvensis (field bindweed) was studied in laboratory and greenhouse conditions. Germination occurred over a wide range of constant temperatures, between 15 and 40 ºC, with optimum germination between 20 and 25 ºC. Time to start germination, time to 50% germination and mean germination time increased while germination percentage and germination index decreased with an increase in temperature from 20 ºC, salinity and osmotic stress. However, germination was tolerant to low salt (25 mM) or osmotic stress (0.2 MPa), but as salinity and osmotic stress increased, germination percentage and germination index decreased. Seeds of C. arvensis placed at soil surface showed maximum emergence and decreased as seeding depth increased. Seeds of C. arvensis germinated over a wide range of pH (4 to 9) but optimum germination occurred at pH 6 to 8. Under highly alkaline and acidic pH, time to start germination, time to 50% germination and mean germination time increased while germination percentage and germination index decreased. Increase in field capacity caused decreased time to start germination, time to 50% germination and mean germination time but increased germination percentage and germination index. Bigger seeds had low time to start germination, time to 50% germination and mean germination time but high germination percentage and germination index. Smaller seeds were more sensitive to environmental factors as compared to larger or medium seeds. It can be concluded that except for pH, all environmental factors and seed sizes adversely affect C. arvensis as regards seed germination or emergence and germination or emergence traits, and larger seeds result in improved stand establishment and faster germination than small seeds, regardless of moisture stress or deeper seeding depth.


2013 ◽  
Vol 31 (2) ◽  
pp. 231-235 ◽  
Author(s):  
Sueyde F de Oliveira ◽  
Denis S da Costa ◽  
Simone da C Mello ◽  
Ana Dionisia da LC Novembre ◽  
Francisco G Gomes-Junior

The objective of the present study was to establish a relationship between mericarps color and internal morphology of parsley with the germination, using sorting by coloration and the X-ray test. The completely randomized design was used, with four replications per treatment. The treatments were constituted of four lots (A, B, C and D) and three mericarps colors (green, yellow and black) in 4×3 factorial experiment. The mericarps were exposed to X-ray test (60s; 20kV), being used the digital equipment Faxitron X-ray, model MX-20 DC12 and then, the irradiated mericarps were submitted to the germination test. The yellow mericarps showed higher germination and speed germination index. The green mericarps showed deformations and impaired formation of embryo, while black and yellow mericarps showed up without deformation and with a well-formed embryo. We concluded that there is a relationship between parsley seed germination and mericarps color. Poorly formed embryos and misshapened seed coats are related to green mericarps.


2021 ◽  
Vol 17 (5) ◽  
pp. 66-72
Author(s):  
Izabele Domingues Soares Miranda ◽  
Manoela Mendes Duarte ◽  
Rodrigo Otávio Veiga de Miranda

The Amazon has a wide diversity, including forest species with timber and non-timber potential, which often have their use restricted due to a lack of silvicultural information. Thus, the present study aimed to evaluate the effect of substrates and temperatures on seed germination of Aspidosperma vagarsii. Therefore, the premise of a completely randomized design was followed, in a 3 x 3 factorial scheme, with three substrates (paper, sand and vermiculite) and three temperatures (20, 25 and 30 °C). The germination percentage, germination speed index and mean germination time were determined, as well as germination relative frequency graphs. In addition, the weight of a thousand seeds, the number of seeds per kilo, and the moisture content was determined. The weight of thousand seeds was equal to 276.4 g, with 3,618 seeds per kilo, and a moisture content of 9.5%. There was no interaction between the studied factors. The sand substrate and temperatures of 20 and 25 °C presented the best results for seed germination of A. vargasii.


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