Effects of achene dimorphism on dormancy and progeny traits in the two ephemerals Hedypnois cretica and Crepis aspera (Asteraceae)

2003 ◽  
Vol 81 (6) ◽  
pp. 550-559 ◽  
Author(s):  
Ali El-Keblawy
Keyword(s):  
Storage Temperature ◽  
Storage Period ◽  
Germination Percentage ◽  
Adaptive Significance ◽  
Dispersal Ability ◽  
Coastal Desert ◽  
Selective Forces ◽  
Germination Behaviour ◽  
Size And Morphology ◽  
The Relationship

Hedypnois cretica (L.) Dum.-Cours. and Crepis aspera L. are ephemeral composites native to the Mediterranean coastal desert of Sinai, Egypt, with marked achene dimorphism. This study examined the relationship between achene morphology and both some progeny traits and germination behaviour in terms of final germination percentage and germination speed. The effects of length of achene storage and temperature of storage on germination behaviour were particularly examined. Fresh harvested seeds showed little germination. After 6 months of storage, central achenes attained higher germination percentages in the two species and germinated faster in C. aspera than the peripheral achenes. The dormancy loss was faster in achenes of H. cretica than in those of C. aspera. Greater germination dimorphism was associated with greater dimorphism in size and morphology and consequently in the dispersal ability of the two morphs of C. aspera than in H. cretica. Warm storage significantly enhanced the germination level and speed of the heavier peripheral achenes compared with those of the central achenes of both species, so this was dependent on storage period. Plants produced by peripheral achenes had a significantly greater size than those from central achenes. This difference was more pronounced in H. cretica and persisted until 70 days postemergence but disappeared after 40 days in C. aspera. Results are discussed in light of possible adaptive significance and selective forces, such as the differential dispersal, dormancy, and growth of the two morphs, that maintain the dimorphism in the unpredictable heterogeneous deserts.Key words: achene dimorphism, Asteraceae, dormancy, germination, storage temperature.

Seed Longevity and Germination Behaviour in Eugenia roxburghii

2021 ◽  
Vol 27 (3) ◽  
pp. 167-171
Author(s):  
Shareef Muhammed ◽  
Chitra Rajeswary ◽  
Anil Chandran
Keyword(s):  
Storage Temperature ◽  
Seed Viability ◽  
Seed Longevity ◽  
Ex Situ ◽  
Hermetic Storage ◽  
Germination Behaviour ◽  
Garden Plant ◽  
Relationship Of ◽  
The Relationship ◽  
And Storage

Eugenia roxburghii is an evergreen graceful shrub with a tremendous potential as garden plant. As a part of ex-situ conservation and popularization of the species, seed longevity was studied by understanding the relationship of seed viability with respect to different moisture contents and storage temperature. Seeds are recognized as recalcitrant, being desiccation as well as chilling sensitive. During hermetic storage, seeds stored at 300C/70%RH retained viability for about 5 months and 4 months in 200C/20% RH. Seeds can be best stored for five months in laboratory conditions.

Fruit and seed polymorphism and its relation to seedling growth in the genus Cakile

1989 ◽  
Vol 67 (9) ◽  
pp. 2743-2750 ◽  
Author(s):  
M. A. Maun ◽  
A. M. Payne
Keyword(s):  
Growth Rate ◽  
Seed Mass ◽  
Germination Percentage ◽  
Dispersal Ability ◽  
Relative Growth ◽  
Frequency Distributions ◽  
Cakile Maritima ◽  
Cakile Edentula ◽  
Germination Behaviour ◽  
Better Than

To ascertain the adaptive significance of dimorphism under unpredictable environments, the dimorphic fruit segments of Cakile edentula var. lacustris, Cakile edentula var. edentula, and Cakile maritima were tested for differences in size of propagules, dispersal ability, germination behaviour, and growth rate. The upper and lower fruit segments differed in some attributes but not in others. For example, the fruits, seeds, and shells of upper segments were significantly heavier than those of lower segments. However, the frequency distributions of mean mass per seed, shell, and fruit indicated a considerable zone of overlap beneath the histograms of upper and lower fruit segments. Under still conditions in a greenhouse, no differences were found in the floating ability of upper and lower fruit segments of C. edentula var. lacustris and C. maritima. Of the three taxa, C. maritima fruits had the highest shell to seed mass ratio and floated for the longest period of time. Morphological seed dimorphism was linked with a physiological seed dimorphism. The lower fruit segments of C. edentula var. lacustris germinated better than the upper fruit segments over a wider range of temperatures. Light did not alter the final germination percentage of upper or lower fruit segments but inhibited the rate of germination. The relative growth rate decreased in all three taxa with an increase in the age of a seedling, irrespective of its seed weight.

scholarly journals Storage and Viability Testing of Protea Pollen

1996 ◽  
Vol 121 (5) ◽  
pp. 804-809 ◽  
Author(s):  
I. David van der Walt ◽  
Gail M. Littlejohn
Keyword(s):  
Storage Temperature ◽  
Pollen Viability ◽  
Germination Percentage ◽  
Long Term Storage ◽  
Fresh Pollen ◽  
The Relationship ◽  
Term Storage ◽  
Storage Temperatures

The influence of storage temperature and humidity on pollen viability was studied in four Protea species. Pollen was stored at a range of temperatures and relative humidities for up to 1 year and tested for ability to germinate in vitro. Pollen of P. repens (L.) L. `Sneyd', P. eximia (Salisb. ex Knight) Fourcade `Fiery Duchess' and P. magnifica Link. clone T 84 07 05 stored at -196 °C and -14 to -18 °C retained a germination percentage as high as that of fresh pollen regardless of humidity. Humidity control became increasingly important at storage temperatures above 0 °C. The study showed that long-term storage of Protea pollen is not feasible at temperatures above 0 °C. The relationship between germinability and fluorochromasia (FCR) was studied during storage of `Sneyd' pollen. The correlations between FCR and germinability were found to be low and nonsignificant. Fifteen-month-old cryopreserved `Sneyd' pollen functioned in fertilization and seed set as effectively as fresh pollen.

scholarly journals Justification of pectin concentrate safe storage terms by pectin mass ratio

2021 ◽  
Vol 4 (11(112)) ◽  
pp. 25-32
Author(s):  
Galiya Iskakova ◽  
Maigul Kizatova ◽  
Meruyet Baiysbayeva ◽  
Sanavar Azimova ◽  
Assel Izembayeva ◽  
...  
Keyword(s):  
Storage Temperature ◽  
Control Sample ◽  
Storage Period ◽  
The Body ◽  
Favorable Effect ◽  
Natural Food ◽  
Safe Storage ◽  
Relationship Of ◽  
The Relationship ◽  
Concentrate Production

The problem of removing heavy and radioactive metals from the human body is relevant all over the world. Recent research has shown that it is more effective to use substances contained in natural food products, including pectin. Pectin has a favorable effect not only under acute exposure to metals, but also with their prolonged entry into the body, which is typical for an environmental load of residents of industrial regions and modern megalopolis. The use of pectin substances as natural detoxicants requires research to preserve these substances in products and further use. Therefore, an important condition for using pectin concentrates is to determine the shelf life for safe consumption. Based on this, studies were conducted to determine optimal storage parameters and terms for pumpkin concentrate. The sequence and parameters of pectin concentrate production from Karina pumpkin pomace are justified. As a result of the study, it was found that during storage of pectin concentrate from Karina pumpkin pomace at a temperature of 8 °C for 10 months, the pectin content in the concentrate decreased by 0–12. 45 %, at 25 °C – by 0–63 %, compared to the control sample. Based on the results, it can be concluded that the safe storage period of pectin-containing concentrates from Karina pumpkin extracts at a temperature of 25 °C is 7 months, at 8 °C – 10 months. As a result of mathematical processing of experimental data, equations for the relationship of pectin amount with storage temperature, pH and time are obtained.

Storage of Human Blood Platelets

1974 ◽  
Vol 32 (02/03) ◽  
pp. 405-416 ◽  
Author(s):  
M. R Hardeman ◽  
Carina J L. Heynens
Keyword(s):  
Storage Temperature ◽  
Platelet Rich Plasma ◽  
Blood Platelets ◽  
Storage Period ◽  
Serotonin Uptake ◽  
Hypotonic Shock ◽  
Glycolytic Intermediates

SummaryStorage experiments were performed at 4°, 25° and 37° C with platelet-rich plasma under sterile conditions. In some experiments also the effect of storing platelets at 4° C in whole blood was investigated.Before, during and after three days of storage, the platelets were tested at 37° C for their serotonin uptake and response to hypotonic shock. In addition some glycolytic intermediates were determined.A fair correlation was noticed between the serotonin uptake and hypotonic shock experiments. Both parameters were best maintained at 25° C. Also platelet counting, performed after the storage period, indicated 25° C as the best storage temperature. Determination of glycolytic intermediates did not justify any conclusion regarding the optimal storage temperature. Of the various anticoagulants studied, ACD and heparin gave the best results as to the serotonin uptake and hypotonic shock response, either with fresh or stored platelets. The use of EDTA resulted in the lowest activity, especially after storage.The results of these storage experiments in vitro, correspond well with those in vivo reported in the literature.

scholarly journals Changes in Particle Size, Sedimentation, and Protein Microstructure of Ultra-High-Temperature Skim Milk Considering Plasmin Concentration and Storage Temperature

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2339
Author(s):  
So-Yul Yun ◽  
Jee-Young Imm
Keyword(s):  
Particle Size ◽  
High Temperature ◽  
Storage Temperature ◽  
Whey Proteins ◽  
Skim Milk ◽  
Storage Period ◽  
Sediment Analysis ◽  
Sediment Formation ◽  
And Storage ◽  
Ultra High Temperature

Age gelation is a major quality defect in ultra-high-temperature (UHT) pasteurized milk during extended storage. Changes in plasmin (PL)-induced sedimentation were investigated during storage (23 °C and 37 °C, four weeks) of UHT skim milk treated with PL (2.5, 10, and 15 U/L). The increase in particle size and broadening of the particle size distribution of samples during storage were dependent on the PL concentration, storage period, and storage temperature. Sediment analysis indicated that elevated storage temperature accelerated protein sedimentation. The initial PL concentration was positively correlated with the amount of protein sediment in samples stored at 23 °C for four weeks (r = 0.615; p < 0.01), whereas this correlation was negative in samples stored at 37 °C for the same time (r = −0.358; p < 0.01) due to extensive proteolysis. SDS-PAGE revealed that whey proteins remained soluble over storage at 23 °C for four weeks, but they mostly disappeared from the soluble phase of PL-added samples after two weeks’ storage at 37 °C. Transmission electron micrographs of PL-containing UHT skim milk during storage at different temperatures supported the trend of sediment analysis well. Based on the Fourier transform infrared spectra of UHT skim milk stored at 23 °C for three weeks, PL-induced particle size enlargement was due to protein aggregation and the formation of intermolecular β-sheet structures, which contributed to casein destabilization, leading to sediment formation.

Annealing effect on the optical and photoelectrochemical properties of lead oxide

2018 ◽  
Vol 84 (3) ◽  
pp. 30301 ◽  
Author(s):  
Wided Zerguine ◽  
Djamila Abdi ◽  
Farid Habelhames ◽  
Meriem Lakhdari ◽  
Hassina Derbal-Habak ◽  
...  
Keyword(s):  
Lead Oxide ◽  
Orthorhombic Phase ◽  
Heat Treatments ◽  
Photoelectrochemical Properties ◽  
X Ray Diffraction ◽  
Vis Spectroscopy ◽  
Size And Morphology ◽  
Two Phases ◽  
P Type ◽  
The Relationship

Effect of the annealing oxidation time of electrodeposited lead (Pb) on the phase formation of lead oxide (PbO) films is reported. The phase structure, optical properties, size and morphology of the films were investigated by scanning electron microscopy, X-ray diffraction and UV-vis spectroscopy. The relationship between structur and photoelectrochemical properties was investigated. Thin films of PbO produced via air annealing of electrodeposited lead consist of a mixture of two phases, orthorhombic (o-PbO) and tetragonal (t-PbO), that determine the material properties and effectiveness as absorber layer in a photoelectrochemical device. The proportion of tetragonal t-PbO increases for longer heat treatments. After 40 h, the sample consists mainly of tetragonal t-PbO. The p-type semiconducting behavior of lead oxide was studied by photocurrent measurements. Different heat treatments yield variations in the ratio of tetragonal to orthorhombic lead oxide that effect on device performances, where devices with a higher content of tetragonal t-PbO show higher photocurrent than with the orthorhombic phase.

PRODUCTION OF GRANULATED INSTANT KISSEL BASED ON WHEY AND VEGETABLE RAW MATERIALS

2020 ◽  
Author(s):  
А.Л. Майтаков ◽  
Л.Н. Берязева ◽  
Н.Т. Ветрова ◽  
К.Б. Плотников
Keyword(s):  
Storage Temperature ◽  
Raw Materials ◽  
Storage Period ◽  
Technical Documentation ◽  
Plant Raw Materials ◽  
Temperature Conditions ◽  
Aronia Melanocarpa ◽  
Organoleptic Characteristics ◽  
Local Plant ◽  
The Stability

Разработан новый быстрорастворимый продукт (кисель) с определенным фазовым составом и строением на основе молочной сыворотки и местного растительного сырья – черноплодной рябины (Aronia melanocarpa). Разработана модель технологии производства быстрорастворимого гранулированного продукта (кисель) на основе молочной сыворотки и черноплодной рябины. Исследована сохраняемость киселя в трех температурных режимах: 1-й (21 ± 1)°С; 2-й с низкой плюсовой температурой (5 ± 1)°С; 3-й с повышенной (39 ± 1)°С при влажности окружающей среды 80%. По окончании годичного исследования сохраняемости при температурных режимах (21 ± 1)°С и (5 ± 1)°С изменений в органолептических показателях продукта не наблюдали. Скорость растворения продукта при температурных условиях хранения (21 ± 1)°С и (5 ± 1)°С не изменялась на протяжении 9 мес. Установлено, что при хранении в условиях пониженных положительных температур 4–6°С и в режиме комнатной температуры (21 ± 1)°С исследуемый пищеконцентрат по окончании 6 мес. хранения не изменил свойств по показателям качества. Сроки испытания продукта превышали по длительности в 2 раза заданный срок хранения (коэффициент запаса). Результаты испытаний явились основанием для разработки технической документации на производство быстрорастворимых гранулированных плодово-ягодных киселей. A new fast – soluble product (kissel) with a certain phase composition and structure based on whey and local plant raw materials Aronia melanocarpa. A model of technology for the production of a rapidly soluble granular product (kissel) based on whey and Aronia melanocarpa has been developed. The stability of kissel in three temperature modes was studied: 1st (21 ± 1)°C; 2nd with a low plus temperature (5 ± 1)°C; the 3rd with the increased (39 ± 1)°C at 80% ambient humidity. At the end of a year-long study at temperature conditions (21 ± 1)°С and (5 ± 1)°С, no changes in the organoleptic characteristics of the product were observed. Dissolution rate of the product under storage temperature conditions (21 ± 1)°C and (5 ± 1)°C did not change for 9 months. It is established that when stored at low positive temperatures 4–6°C. With and at room temperature (21 ± 1)°C. At the end of 6 months of storage, the food concentrate under study did not change its properties in terms of quality. The product testing period was 2 times longer than the specified storage period. The test results were the basis for the development of technical documentation for the production of instant granulated fruit and berry kissel.

Effects of Storage Temperature and Preservative Treatment on Shelf Life of the Pond-Raised Freshwater Fish, Silver Perch (Bidyanus bidyanus)

2001 ◽  
Vol 64 (10) ◽  
pp. 1584-1591 ◽  
Author(s):  
A. GELMAN ◽  
L. GLATMAN ◽  
V. DRABKIN ◽  
S. HARPAZ
Keyword(s):  
Shelf Life ◽  
Cold Storage ◽  
Storage Temperature ◽  
Storage Period ◽  
Potassium Sorbate ◽  
Test Results ◽  
Bacterial Composition ◽  
Fish Flesh ◽  
Microbiological Characteristics ◽  
Initial Load

Sensory and microbiological characteristics of pond-raised freshwater silver perch (Bidyanus bidyanus) fish, during cold storage over a period of 25 days were evaluated. Whole fish (averaging 400 g each) were stored in cold storage rooms at either 0 to 2°C, 5°C, or 5°C + potassium sorbate as a preservative. The organoleptic and hypoxanthine test results show that the treatment of potassium sorbate can slow the process of spoilage by about 5 days. Yet, the most important factor affecting the shelf life of these fish is the storage temperature. Keeping the fish at 0 to 2°C can prolong the storage prior to spoilage by 10 days compared with those kept at 5°C. These results obtained through organoleptic tests are corroborated by both the chemical (hypoxanthine and total volatile basic nitrogen) and to some extent by the physical (cosmos) tests. The initial total bacteriological counts were 5 × 102 CFU/cm2 for fish surface and &lt;102 CFU/g for fish flesh, and these counts rose continuously, reaching about 106 CFU/g (0 to 2°C) and 107 CFU/g (5°C) in flesh and 107 to 108 CFU/cm2 on the surface by the end of the storage period. The addition of potassium sorbate led to a smaller increase in bacterial numbers, especially during the first 15 days. Bacterial composition fluctuated during storage. The initial load on the fish surface was predominantly mesophilic and gram positive and consisted mostly (80%) of Micrococci, Bacillus, and Corynebacterium. During the next 10 days, these bacteria were practically replaced by gram-negative flora comprised mostly of Pseudomonas fluorescens that rapidly increased with storage time and accounted for 95% after 15 days.

The use of postharvest treatments to extend storage life and to control postharvest wastage of honeydew melons (Cucumis melo L. var. inodorus Naud.) in cool storage

1990 ◽  
Vol 30 (5) ◽  
pp. 693 ◽  
Author(s):  
ME Edwards ◽  
RM Blennerhassett
Keyword(s):  
Water Loss ◽  
Cucumis Melo ◽  
Storage Temperature ◽  
Chilling Injury ◽  
Storage Period ◽  
Storage Conditions ◽  
Storage Life ◽  
Storage Rots ◽  
Wax Coating ◽  
Cucumis Melo L

Three trials were undertaken to study storage conditions and handling procedures required to maximise the postharvest storage life of honeydew melons (Cucumis melo L. var. inodorus Naud.).Honeydew melons treated with chlorine (1000 mg/L), benomyl (250 mg/L) + guazatine (500 mg/L), shrink wrap (17 ym Cryovac XDR film), Semperfresh, wax, or combinations of these treatments were stored at 4 or 8�C, for 4 or 6 weeks. Benomyl plus guazatine reduced the development of storage rots associated with Alternaria and Fusarium spp. The use of shrink wrap and wax reduced water loss by melons but increased fungal infection in some cases. Shrink wrapping combined with the fungicide treatment effectively reduced the incidence of fungal breakdown in the storage period for up to 4 weeks. Wax coating with full strength Citruseal wax caused anaerobic tissue breakdown. Melons were affected by chilling injury at 4�C. Control of bacterial rots with benomyl + guazatine or with chlorine was variable. Semperfresh did not reduce the incidence of fungal breakdown or water loss from the melons. The results indicate that storage of honeydew melons for 4 weeks at 8�C by pretreating with fungicide is possible but the melons soften and rot after 6 weeks, making them unsaleable. Four weeks should be adequate to allow for sea freighting of honeydew melons to markets in South East Asia. Further research is required to determine the optimum storage temperature for honeydew melons.

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