scholarly journals Pollination of Dendrobium Hybrids Using Cryopreserved Pollen

HortScience ◽  
2008 ◽  
Vol 43 (1) ◽  
pp. 264-267 ◽  
Author(s):  
Wagner A. Vendrame ◽  
Virginia S. Carvalho ◽  
José M.M. Dias ◽  
Ian Maguire
Keyword(s):  
Liquid Nitrogen ◽  
Room Temperature ◽  
Seed Viability ◽  
Viability Test ◽  
Pollination Effectiveness ◽  
High Viability ◽  
Leaves And Roots ◽  
Germinating Seeds

Pollination effectiveness was evaluated for pollen (pollinia) from two Dendrobium hybrids, ‘Sena Red’ and ‘Mini WRL’, submitted to cryopreservation using a vitrification protocol. Parameters evaluated included pollinia exposure to a previtrification solution (PVS2) under ice (0 °C) or room (27 ± 2 °C) temperatures from 1 to 4 hours before cryopreservation (LN). On removal from cryopreservation, pollinia were used to pollinate flowers of the same hybrids to verify viability and germination. All pollinia showed high percentages of germination (greater than 80%) after crosses were performed, except for pollinia from Dendrobium ‘Sena Red’ submitted to 3 hours of precooling (0 °C) in PVS2 followed by LN (60%) and for pollinia submitted to PVS2 for 3 hours at room temperature with no precooling (70%). Capsules were formed for both hybrids and seeds were successfully produced. The seed viability test revealed high viability (90% to 95%) for all treatments for both hybrids. Seeds observed under a microscope contained well-formed embryos and no abnormalities were identified. Seeds from all treatments germinated. Germinating seeds developed into healthy seedlings with well-formed leaves and roots. Cryopreservation of pollinia was successfully accomplished either by direct storage in liquid nitrogen without cryoprotection treatments or by using a PVS2 vitrification protocol.

scholarly journals Development of cryopreservation methods of seed of Nepeta cataria

2021 ◽  
Vol 102 (2) ◽  
pp. 37-42
Author(s):  
Margarita Ishmuratova ◽  
◽  
Damirzhan Baigarayev ◽  
Saltanat Tleukenova ◽  
Elena Gavrilkova ◽  
...  
Keyword(s):  
Liquid Nitrogen ◽  
Room Temperature ◽  
Seed Viability ◽  
Positive Temperature ◽  
Seed Rate ◽  
Nepeta Cataria ◽  
Long Term Storage ◽  
Medical Plant ◽  
Term Storage

This article presents the summarized data on cryopreservation of seeds of the medical plant Nepeta cataria. Cryopreservation is a highly promising method for saving of seed materials, allowing to organize long-term storage without viability loss. The purpose of present work is to optimize conditions of cryopreservation of seed materials of Nepeta cataria. Assessment of seed survival rate in the storage showed a linear decrease in seed viability and energy of germination. After 30 months of storage at the low positive temperature (+5 ºC) in paper pack seed rate decreased to 12.0 % and energy of germination to 11.2 %; after 4 years of storage seeds lost viability. During conduction of research the type of container, condition of thawing, optimal moisture of seeds and cryoprotectants are optimized. The optimal container for cryopreservation in liquid nitrogen was plastic cryo tubes; defrosting at room temperature. The best seed rate is found at moisture 3 %; the best cryoprotectant was glucose, the optimal concentration was 15 %. The result of the research is used for creation of the long-term storage medicinal cultures’ seed bank in the liquid nitrogen.

scholarly journals Germination Temperature and the Effect of Storage Time on the Seed Viability of Zephyra elegans (Tecophilaeaceae)

HortScience ◽  
2018 ◽  
Vol 53 (6) ◽  
pp. 887-890
Author(s):  
Carlos De la Cuadra ◽  
Alexis K. Vidal ◽  
Patricia Peñaloza ◽  
Leví Mansur ◽  
Carlos Huenchuleo
Keyword(s):  
Room Temperature ◽  
Natural Habitat ◽  
Seed Viability ◽  
Dry Storage ◽  
High Viability ◽  
High Germination ◽  
Temperature Requirements ◽  
Variable Precipitation ◽  
Storage Times ◽  
Desert Climate

Zephyra elegans is a geophyte endemic to Chile that has horticultural value as a cut flower. Its natural habitat is a coastal desert climate with abundant cloud cover, little and variable precipitation, and mean monthly temperatures between 10 and 20 °C. It is hypothesized that the temperature requirements for germination of Z. elegans seeds are similar to those of Zephyra compacta, which shares the same habitat. As it is a species from a desert climate, it can be expected that its seeds remain viable during long periods of storage. The seeds used in this study were harvested in different years from plants grown from cultivated corms of Z. elegans. The germination test temperatures were 10, 15, 20, and 25 °C, and the dry storage times at room temperature (20 ± 5 °C) were 4, 16, 28, and 40 months. The temperature requirements for germination of Z. elegans seeds are similar to those of Z. compacta, which has been studied earlier, i.e., the temperature range for achieving high germination percentages is 10 to 20 °C, whereas 25 °C can be considered supraoptimal. After-ripening of the seeds occurred during dry storage, as shown by increased germination when tested at a supraoptimal temperature. The seeds had high viability after 40 months of dry storage at room temperature.

scholarly journals SEED VIABILITY TEST OF COMMERSIAL DATES ON THE MARKET

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
Ekosari Roektiningroem ◽  
Purwanti Widhy
Keyword(s):  
Room Temperature ◽  
Germination Rate ◽  
Seed Viability ◽  
Dry Weight ◽  
Germination Percentage ◽  
State University ◽  
Germination Test ◽  
Viability Test ◽  
Seed Moisture ◽  
Dark Orange

This research aims to to know the seed viability of the two dates on the market. It has been done from July to November 2014, in the laboratory of  Mathematics and Natural Science Faculty, Yogyakarta State University. The type of Dates seeds are Sayer (oval-cilindrical, ±3cm, dark orange brown/more light than another),  and Lulu (round, ±2cm, dark maroon reddish /more dark than Sayer’s). Viability test by germination testing; conducted on plastic tray with cotton sheet and fabric covered; fill with 100 grains of seeds. Repeated 4 times. Incubation at room temperature (±30oC). The parameters were seed fresh weight, seed dry weight, seed moisture, germination percentage and germination rate. The results were analyzed by compare mean - independent samples t test of SPSS 18’th. The results showed that the viability of both of Date’s seeds from local’s market (Sayer and Lulu) is high. Sayer’s have better viability than Lulu’s (due to the germination percentage and germination rate). Keywords: date seed, viability test, germination test

scholarly journals BIOCHEMICAL ANALYSES OF SEED EXUDATES DURING EARLY IMBIBITION

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 684g-685
Author(s):  
Eric E. Roos ◽  
Sharon Sowa ◽  
Kristin Pedas
Keyword(s):  
Oryza Sativa ◽  
Protein Concentration ◽  
Room Temperature ◽  
Seed Viability ◽  
Distilled Water ◽  
Short Term ◽  
Time Period ◽  
High Viability ◽  
Biochemical Analyses ◽  
Bca Assay

Short term soaking of seeds does not appear to be detrimental to seed viability and may provide a means of testing seed viability non-destructively. Seeds of corn (Zea mays L.) and rice (Oryza sativa L.), differing in viability, were soaked for 0.5, 1, 2 and 4 hr in distilled water at room temperature. Analyses of pH, protein/polypeptides (BCA assay and absorbance at 280 nm), and potassium (and other metals), were done on individual seed leachates. After each time period seeds were germinated for 7 d to determine viability. For both corn and rice, pH remained constant between 0.5 and 4 hr of soaking. Protein concentration gradually increased during the 4 hr soak in both corn and rice, but varied with seed lot. Potassium was the most common metal excreted and increased 3 to 4 fold between 0.5 and 4 hr of soaking. Although seed to seed variability in any given lot was high, in general, low viability seeds lost more cellular constituents than high viability seeds.

A Liquid Nitrogen Cooled Stage for STEM

1974 ◽  
Vol 32 ◽  
pp. 444-445
Author(s):  
Louis T. Germinario
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Liquid Nitrogen ◽  
Room Temperature ◽  
Objective Lens ◽  
Thermal Drift ◽  
Specimen Holder ◽  
Resolution Capability ◽  
Focal Position

A liquid nitrogen stage has been developed for the JEOL JEM-100B electron microscope equipped with a scanning attachment. The design is a modification of the standard JEM-100B SEM specimen holder with specimen cooling to any temperatures In the range ~ 55°K to room temperature. Since the specimen plane is maintained at the ‘high resolution’ focal position of the objective lens and ‘bumping’ and thermal drift la minimized by supercooling the liquid nitrogen, the high resolution capability of the microscope is maintained (Fig.4).

scholarly journals Seed germination requirements of Hypericum scruglii, an endangered medicinal plant species of Sardinia (Italy)

Botany ◽  
2020 ◽  
Vol 98 (10) ◽  
pp. 615-621 ◽  
Author(s):  
Marco Porceddu ◽  
Martina Sanna ◽  
Sara Serra ◽  
Maria Manconi ◽  
Gianluigi Bacchetta
Keyword(s):  
Medicinal Plant ◽  
Seed Bank ◽  
Seed Viability ◽  
Base Temperature ◽  
Endemic Plant ◽  
Endangered Medicinal Plant ◽  
High Viability ◽  
Wide Range ◽  
Baseline Information ◽  
Germination Requirements

Hypericum scruglii Bacch., Brullo & Salmeri is an endangered endemic plant of Sardinia, and the phloroglucinol compounds identified in this species have been reported to inhibit the activity of the Human Immunodeficiency Virus. Seed banks are a genetic repository that effectively preserve taxa of conservation interest, and they hold knowledge about the biology and germination ecophysiology of the taxa they preserve. The main goals of this study were to investigate the germination requirements for H. scruglii, to evaluate the seed viability after eight years of long-term conservation and to suggest an efficient protocol for germination. Seeds stored at –25 °C in the seed bank were tested at temperatures from 5 to 30 °C and 25/10 °C. Base temperature (Tb) and thermal time (θ50) for germination were estimated. Seeds of H. scruglii germinated over a wide range of temperatures, responding positively to high temperatures and 25/10 °C. Tb was estimated at 4.92 °C, and θ50 was estimated at 198.27 degree days. The high viability detected in seeds of H. scruglii allows us to suggest the use of seeds stored in a seed bank when fresh material for plant propagation is scarce. Our results provide new and useful baseline information for implementing conservation and multiplication strategies for this endangered medicinal plant.

Cryogenic Interlaminar Properties of PBO Fiber/Epoxy Composites

2011 ◽  
Vol 391-392 ◽  
pp. 1445-1449
Author(s):  
Chun Hua Zhang ◽  
Shi Lin Luan ◽  
Xiu Song Qian ◽  
Bao Hua Sun ◽  
Wen Sheng Zhang
Keyword(s):  
Liquid Nitrogen ◽  
Room Temperature ◽  
Liquid Nitrogen Temperature ◽  
Epoxy Composites ◽  
Bending Test ◽  
Test Results ◽  
Sem Images ◽  
Three Point Bending ◽  
Pbo Fiber ◽  
Interlaminar Shear

The influences of low temperature on the interlaminar properties for PBO fiber/epoxy composites have been studied at liquid nitrogen temperature (77 K) in terms of three point bending test. Results showed that the interlaminar shear strength at 77 K were significantly higher than those at room temperature (RT). For the analysis of the test results, the tensile behaviors of epoxy resin at both room temperature and liquid nitrogen temperature were investigated. The interface between fiber and matrix was observed using SEM images.

scholarly journals Responses of quinoa (Chenopodium quinoa Willd.) seeds stored under different germination temperatures

2017 ◽  
Vol 39 (1) ◽  
pp. 83 ◽  
Author(s):  
Andressa Strenske ◽  
Edmar Soares de Vasconcelos ◽  
Vanessa Aline Egewarth ◽  
Neusa Francisca Michelon Herzog ◽  
Marlene De Matos Malavasi
Keyword(s):  
Room Temperature ◽  
Storage Time ◽  
Chenopodium Quinoa ◽  
Seed Vigor ◽  
Continuous Darkness ◽  
Experimental Conditions ◽  
Growing Seasons ◽  
Germinating Seeds ◽  
Germinated Seeds ◽  
Plot Design

In this experiment, we assessed the germination and vigor of quinoa seeds packed in paper bags and stored at room temperature for 36, 85, 119, 146, 177 and 270 days. The seeds were harvested under experimental conditions in Marechal Candido Rondon, Paraná, during the 2012/13 growing seasons. Four replicates of 100 seeds each were established for each storage time, and the seeds were evaluated, on paper, based on the BOD under the following experimental temperature conditions: alternating temperatures of 20 and 30°C and a constant temperature of 25°C. The seeds from both treatments were subject to seven-hour photoperiods and 25°C under continuous darkness. The germinated seeds were counted daily for eight days after sowing, and we evaluated the percentages of normal and abnormal seedlings and the germination index. The experimental design was completely randomized using a split-plot design. Increasing the storage time decreased the percentage of germinated seeds and seed vigor due to the increased number of abnormal seedlings. Over the 430-day study period, quinoa seed germination completely declined under the experimental conditions. The final number of germinating seeds should be evaluated 7 days after the beginning of the germination test. 

scholarly journals The effect of storage conditions on samples for the evaluation of copper status in blesbok (Damaliscus pygargus phillipsi)

2002 ◽  
Vol 73 (3) ◽  
Author(s):  
M. Quan ◽  
M.S. Mulders ◽  
D.G.A. Meltzer
Keyword(s):  
Superoxide Dismutase ◽  
Liquid Nitrogen ◽  
Liver Tissue ◽  
Room Temperature ◽  
Storage Conditions ◽  
Superoxide Dismutase Activity ◽  
Activity Levels ◽  
Sample Storage ◽  
Live Animal ◽  
Jersey Cows

Investigaltions to determine the effect of sample storage on the concentration of copper in liver tissue and on the activity of erythrocyte superoxide dismutase were undertaken in preparation for a study of blesbok (Damaliscus pygargus phillipsi) that were suspected to be suffering from copper deficiency. Two liver samples were collected from each of 20 culled blesbok in a manner that simulated the collection of biopsies from the live animal. These samples were stored either in 10 % formalin or frozen at -20 °C until analysed 4 1/2 months later. The effect of different methods of sample storage on superoxide dismutase activity was determined. Erythrocytes collected from 3 Jersey cows and 5 culled blesbok were washed and divided into 0.5m portions, stored at room temperature (~20 °C), in a refrigerator (4 °C), frozen at -20 °C in a freezer, and in liquid nitrogen (-200 °C). An analysis of superoxide dismutase activity was undertaken using a commercial assay kit at intervals of 2-4 days until the levels of activity had fallen significantly. The copper concentration in formalin-preserved liver samples was significantly lower than that measured in frozen liver tissue apparently as a result of leaching. The activity of superoxide dismutase in cattle blood was unchanged for 4 days at room temperature but fell appreciably after 2 days at 4 °C and -20 °C. Enzyme activity remained unchanged for 200 days in erythrocytes stored in liquid nitrogen. Superoxide dismutase activity levels in healthy blesbok were considerably lower than those measured in Jersey cows and remained unaffected for up to 6 days in samples stored at 4 °C and 20 °C. The level of activity fell significantly thereafter. Samples stored in liquid nitrogen were unchanged after 40 days.

scholarly journals Non-Deep Physiological Dormancy in Seed and Germination Requirements of Lysimachia coreana Nakai

Horticulturae ◽  
2021 ◽  
Vol 7 (11) ◽  
pp. 490
Author(s):  
Saeng Geul Baek ◽  
Jin Hyun Im ◽  
Myeong Ja Kwak ◽  
Cho Hee Park ◽  
Mi Hyun Lee ◽  
...  
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Germination Rate ◽  
Seed Viability ◽  
Cold Stratification ◽  
Dormancy Breaking ◽  
Viability Test ◽  
Physiological Dormancy ◽  
Different Temperatures ◽  
Germination Requirements

This study aimed to determine the type of seed dormancy and to identify a suitable method of dormancy-breaking for an efficient seed viability test of Lysimachia coreana Nakai. To confirm the effect of gibberellic acid (GA3) on seed germination at different temperatures, germination tests were conducted at 5, 15, 20, 25, 20/10, and 25/15 °C (12/12 h, light/dark), using 1% agar with 100, 250, and 500 mg·L−1 GA3. Seeds were also stratified at 5 and 25/15 °C for 6 and 9 weeks, respectively, and then germinated at the same temperature. Seeds treated with GA3 demonstrated an increased germination rate (GR) at all temperatures except 5 °C. The highest GR was 82.0% at 25/15 °C and 250 mg·L−1 GA3 (4.8 times higher than the control (14.0%)). Additionally, GR increased after cold stratification, whereas seeds did not germinate after warm stratification at all temperatures. After cold stratification, the highest GR was 56.0% at 25/15 °C, which was lower than the GR observed after GA3 treatment. We hypothesized that L. coreana seeds have a non-deep physiological dormancy and concluded that 250 mg·L−1 GA3 treatment is more effective than cold stratification (9 weeks) for L. coreana seed-dormancy-breaking.

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