scholarly journals Germination of Croton urucurana L. seeds exposed to different storage temperatures and pre-germinative treatments

2012 ◽  
Vol 84 (1) ◽  
pp. 191-200 ◽  
Author(s):  
Silvana P.Q. Scalon ◽  
Rosilda M. Mussury ◽  
Andréa A. Lima

The present work evaluated the germinability and vigor of Croton urucurana seeds. 1) Seeds were sorted by color (caramel, gray and black) and were subjected to seven different pre-germination treatments followed by incubation at 20ºC, 25°C or 20/30°C. 2) Seeds were stored in cold chambers or at room temperature for up to 300 days and were subsequently incubated at 20/30ºC in a germination chamber or under greenhouse conditions. Only gray seeds showed significant germination rates. The highest first count percentages of total germination and the highest germination speed indices were observed in control seeds and in those which were treated with water or 200 mg. L-1 gibberellic acid for 12 hours. Seeds stored under refrigeration showed the highest values for all of the characteristics examined, as well as less electrical conductivity of the imbibing solution. Seedlings were more vigorous when seeds were stored for 300 days in a cold chamber. The seedlings production can be increased by incubating the seeds at alternating temperatures (20/30°C). The seeds do not need pre-germination treatments.

2017 ◽  
Vol 63 (No. 9) ◽  
pp. 417-424 ◽  
Author(s):  
Ahmadloo Fatemeh ◽  
Kouchaksaraei Masoud Tabari ◽  
Goodarzi Gholam Reza ◽  
Salehi Azadeh

This study investigated methods to overcome seed dormancy in Crataegus pseudoheterophylla Pojarkova seeds. Seeds with and without endocarps were treated with gibberellic acid (GA<sub>3</sub>) at different concentrations and four storage temperatures. Then they were stratified in an alternate temperature regime. The amount of absorbed water in seeds with endocarps was monitored by measuring the fresh weight of seeds for 0, 24, 48, 72, and 96 h of imbibition. The electrical conductivity (EC) and the percentage of water uptake by seeds stored for 12 months at laboratory temperature, in a refrigerator, in a freezer, and in freeze-thaw conditions were measured. The highest germination (59.7%) was recorded in seeds without endocarps treated with 3,000 mg·l<sup>–1</sup> GA<sub>3 </sub>and stored either in a laboratory or a refrigerator (32.7–35.3%). All treatments of seeds without endocarps where GA<sub>3</sub> was applied showed statistically higher percentages of germination than the control. Seeds with endocarps stored at refrigerator temperature imbibed water up to 44.3% with increasing imbibition periods, whereas the amount of seeds that absorbed water in freezer and freeze-thaw conditions was almost the same. The tests showed the highest EC during storage in the freezer, with the lowest water uptake and viability in seeds stored during the freeze-thaw process.


2005 ◽  
Vol 9 (4) ◽  
pp. 591-595
Author(s):  
Lígia M. de M. Silva ◽  
Ivor B. de Aguiar ◽  
Déborah L. de Morais ◽  
Ricardo A. Viegas ◽  
Joaquim A. G. Silveira

This work aimed to determine the best environment for conservation of physiological quality of seeds of Cnidosculus phyllacanthus during storage. Seeds with 8.5% moisture content and 86% germinative capacity were filled in containers of different permeability, and storaged at different conditions during 360 days. Seeds packed in permeable container (paper bag) were stored at ordinary room temperature (18 to 25 ºC and 55 to 78% RH), and dry chamber (18 ºC and 60% RH) while those packed in semipermeable (polyethylene bag) and impermeable (glass) containers were stored in cold chamber (10 ºC and 75% RH). Seed moisture content, germinative capacity and germination speed were evaluated each 90 days interval. For all the tested storage conditions, seed germination speed was reduced at first evaluation and stabilized up to 360 days. Great deterioration in seeds stored at ordinary room condition was observed, while those stored in dry chamber maintained its germinative capacity for 270 days. The seed germinative capacity was better retained in cold storage, packaged either in semipemeable or impermeable containers. During storage, the seeds had a behavior classified as orthodox.


1994 ◽  
Vol 359 ◽  
Author(s):  
Jun Chen ◽  
Haiyan Zhang ◽  
Baoqiong Chen ◽  
Shaoqi Peng ◽  
Ning Ke ◽  
...  

ABSTRACTWe report here the results of our study on the properties of iodine-doped C60 thin films by IR and optical absorption, X-ray diffraction, and electrical conductivity measurements. The results show that there is no apparent structural change in the iodine-doped samples at room temperature in comparison with that of the undoped films. However, in the electrical conductivity measurements, an increase of more that one order of magnitude in the room temperature conductivity has been observed in the iodine-doped samples. In addition, while the conductivity of the undoped films shows thermally activated temperature dependence, the conductivity of the iodine-doped films was found to be constant over a fairly wide temperature range (from 20°C to 70°C) exhibiting a metallic feature.


1998 ◽  
Vol 545 ◽  
Author(s):  
Ke-Feng Cai ◽  
Ce-Wen Nan ◽  
Xin-Min Min

AbstractB4C ceramics doped with various content of Si (0 to 2.03 at%) are prepared via hot pressing. The composition and microstructure of the ceramics are characterized by means of XRD and EPMA. Their electrical conductivity and Seebeck coefficient of the samples are measured from room temperature up to 1500K. The electrical conductivity increases with temperature, and more rapidly after 1300K; the Seebeck coefficient of the ceramics also increases with temperature and rises to a value of about 320μVK−1. The value of the figure of merit of Si-doped B4C rises to about 4 × 10−4K−1 at 1500K.


2011 ◽  
Vol 13 (4) ◽  
pp. 507-511 ◽  
Author(s):  
J.M. Vasconcelos ◽  
M.A. Rodrigues ◽  
S.C. Vasconcelos Filho ◽  
J.F. Sales ◽  
F.G. Silva ◽  
...  

"Quina" (Strychnos pseudoquina A. St. Hil) is a medicinal plant species from the Brazilian Cerrado. As its seeds show dormancy, they were subjected to the treatments pre-cooling at 5ºC during 7 days, pre-heating at 40ºC during 7 days, pre-soaking in sulfuric acid PA during 5 and 15 min, pre-soaking in boiling water during 5 and 15 min, pre-soaking in 100 and 200 ppm gibberellic acid during 48 h, pre-soaking in distilled water during 24 and 48 h, and mechanical scarification to break dormancy. Counts were daily conducted from the 2nd day after the experiment implementation until the germination stabilization at the 65th day. The germination speed index (GSI) and the germination percentage were evaluated. Germination rates above 96% were reached in seeds pre-soaked in water during 48 h and substrate moistened with water or KNO3.


2013 ◽  
Vol 35 (1) ◽  
pp. 42-50 ◽  
Author(s):  
Fábio Mielezrski ◽  
Julio Marcos-Filho

Research on pea seed storage and the identification of efficient seed vigor tests for this species is still insufficient, especially for cultivars that produce wrinkled seeds used for consumption in natura. The objective of this study was to verify the accuracy of tests to assess the physiological potential of pea seed lots stored in different environments. Four seed lots of two cultivars, 'Telefone Alta' (indeterminate growth habit) and 'Itapuã' (determinate growth habit) were stored under different environmental conditions for 8 months: a) laboratory uncontrolled b) dry and cold chamber (10 ºC and 30% RH), c) controlled environment (20 ºC and 70% RH). Seed vigor (accelerated aging, electrical conductivity, seedling length and seedling emergence) was evaluated initially and after four and eight months storage. Results showed that the use of seed lots of high initial physiological potential is fundamental for guaranteeing the desired performance of pea seeds during storage. Wrinkled pea seeds should be stored between harvest and sowing in an environment in which the sum of the relative humidity (%) and temperature (°C) does not exceed 70. Physiological potential of pea seeds should be evaluated by at least two vigor tests; consideration to accelerated aging and electrical conductivity tests is recommended.


Author(s):  
Jakellinye Miranda ◽  
Suélen Braga de Andrade, Andressa Vighi Schiavon ◽  
Pedro Luis Panisson Kaltbach Lemos ◽  
Cláudia Simone Madruga Lima ◽  
Marcelo Barbosa Malgarim

Peach is a climacteric highly-perishable fruit whose post-harvest preservation relies largely on cold storage. The combination of the last with other technologies allows to extend the shelf life of this product. One alternative is the utilization of salicylic acid, a natural compound involved in many physiological phenomena such as resistance against diseases and ripening. Considering these facts, the objective of the present work was to evaluate the effect of pre-harvest application of salicylic acid solutions on the quality of ‘Chimarrita’ peaches during post-harvest cold storage. The experiment was conducted at the Federal University of Pelotas/RS, in the campus of Capão do Leão/RS - Brazil. The application of salicylic acid solutions was performed by direct pulverization on the fruits, 30 days prior to harvest. The concentrations were: 0,0 (control); 1,0; 1,5; and 2,0 mM. After harvest, the fruits were stored in a cold chamber at 1,0 ± 0,5°C and 85-90% RH, for 30 days. The analyses were performed at the following cold storage periods (plus 2 days at room temperature of 20°C to all treatments, in order to simulate commercialization conditions): 10 (+2) days; 20 (+2) days; e 30 (+2) days. The variables evaluated were: mass loss (%); flesh firmness (N); DA index; color (L, a*, b* and hue angle); wooliness incidence (%); rot incidence (%); total soluble solids (°Brix); pH; titrable acidity (% of organic acids); and ratio. The salicylic acid doses and/or the cold storage periods had significant effects on all the evaluated parameters. For most of the parameters analyzed, the intermediate dosis of 1mM (and also 1,5mM) of salicilic acid showed the most promising results. Therefore, the application of salicylic acid solutions 30 days prior to harvest is a technique which can be combined to cold storage in order to shift the quality and the shelf-life of ‘Chimarrita’ peaches.


Nativa ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 317
Author(s):  
Cássio Do Prado Borges ◽  
Cheila Deisy Ferreira ◽  
Daniela Pereira Dias

Este trabalho objetivou avaliar a germinação e vigor de sementes de Plathymenia reticulata Benth. submetidas a diferentes tratamentos para superação de dormência. Os tratamentos testados foram: controle - sementes intactas (T0), escarificação mecânica com lixa d’água nº 60 (T1), desponte na região lateral do tegumento (T2), imersão em água fervente por 10 min (T3), em hipoclorito de sódio por 15 min (T4) e em solução com detergente por 15 min (T5). Foram determinados: peso de mil sementes, grau de umidade, porcentagem de germinação, índice de velocidade de germinação (IVG), tempo médio de germinação (TMG), curva de embebição, teste da condutividade elétrica e comprimento da radícula. A porcentagem de germinação das sementes submetidas ao T1 e T2 foi estatisticamente igual (respectivamente, 90 e 88%) e superiores aos outros tratamentos testados (12%). As sementes expostas aos T1 e T2 apesentaram porcentagem de absorção de água superiores e em menor tempo, assim como maiores IVG e menores TMG, comparadas aos demais tratamentos. O comprimento das radículas não variou entre os tratamentos testados. A condutividade elétrica da solução com as sementes do T0 foi superior aos outros tratamentos testados. Sementes de P. reticulata expostas ao T1 e T2 apresentam maior germinação e vigor.Palavras-chave: germinação, índice de velocidade de germinação, teste de condutividade elétrica, vigor, vinhático. DORMANCY BREAKING OF Plathymenia reticulata Benth. SEEDS ABSTRACT:This study aimed to evaluate the germination and vigor of Plathymenia reticulata Benth. seeds submitted to different dormancy breaking treatments. Testing treatments were: control - intact seeds (T0); mechanical scarification with sandpaper n. 60 (T1), coating cutting in the lateral side of tegument (T2), immersion in boiling water during 10 min (T3), in sodium hypochlorite solution during 15 min (T4), and in detergent solution during 15 min (T5). Moisture content, 1000-seed weight, germination percentage, germination speed index (GSI), mean germination time (MGT), imbibition curve, electrical conductivity test, and radicle length were determined. Germination percentage to T1 and T2 were statistically equal (90 and 88 %, respectively) and higher than others treatments tested (12%). Seeds exposed to T1 and T2 also presented higher and faster water absorption percentage, when compared to the others treatments, as well as higher GSI, and lower MGT. The rootlets length did not vary among treatments tested. Electrical conductivity of intact seeds was higher than others treatments. P. reticulata seeds expose to T1 e T2 had highest germination percentage and vigor.Keywords: germination, germination speed index, electrical conductivity test, vigor, vinhático.


2021 ◽  
Vol 35 (1) ◽  
Author(s):  
Carol Mutua ◽  
Joshua Ogweno ◽  
Robert Gesimba

The present study evaluated the effect of NPK fertilizer (17:17:17) rates (0, 100, 200, 300 and 400 kg ha-1) on the postharvest quality of field and greenhouse grown pepino melons (Solanum muricatum Ait.) stored at room temperature (15-22°C) and at low temperature (7°C). The study was carried out in randomized complete block design with fruits from the field and greenhouse, five NPK fertilizer rates as treatments and the two storage temperatures replicated three times. Data were collected on percentage fruit weight loss (PWL), total soluble solids (TSS), firmness and shelf life. Results indicated that greenhouse and field grown fruits from the control and plants supplied with 100 kg NPK ha-1 had low PWL at both storage temperatures. Field grown fruits from the control stored at room temperature had the highest TSS and were firmer after 28 days of storage. Field grown fruits not supplied with fertilizer and stored at low temperature had a shelf life of 27 and 26 days in trial one and two respectively. Application of 100 kg NPK ha-1 and storage of pepino melon fruits at low temperature can be used to enhance quality and shelf life.


2016 ◽  
Vol 77 (3) ◽  
pp. 431-436 ◽  
Author(s):  
F. C. Nery ◽  
D. O. Prudente ◽  
A. A. Alvarenga ◽  
R. Paiva ◽  
M. C. Nery

Abstract Calophyllum brasiliense is a species native to Brazil and has potential for use in the timber industry, in the reforestation of degraded areas, besides having medicinal properties. Its propagation is mainly by seeds which, depending on their recalcitrant characteristics, leads to difficulty in conservation, due to changes in its physiological potential during storage. Aiming to contribute to the expansion of its cultivation, rational use and conservation, the objective of this study was to investigate the behavior of C. brasiliense seeds during storage. Different packings (paper, aluminum and polyethylene) and environmental conditions (room temperature and cold chamber) were quarterly tested over 12 months, by evaluating germination viability and vigor. Based on the results, it was concluded that packaging in polyethylene and freezer storage provided the best conditions for the conservation of seeds, keeping them viable for a period of nine months.


Sign in / Sign up

Export Citation Format

Share Document