Cultivar and storage effects on germination and hard seed content of alfalfa

1999 ◽  
Vol 79 (2) ◽  
pp. 201-208 ◽  
Author(s):  
S. N. Acharya ◽  
D. G. Stout ◽  
B. Brooke ◽  
D. Thompson
Keyword(s):  
Medicago Sativa ◽  
Liquid Nitrogen ◽  
Storage Conditions ◽  
Temperature Treatment ◽  
Short Exposure ◽  
High Temperature Treatment ◽  
Hard Seed ◽  
Seed Content ◽  
Hard Seeds ◽  
And Storage

The impermeable coat of alfalfa (Medicago sativa L.) seed can reduce germination to an extent unacceptable for commercial use. The usual method of increasing germination of lots with high proportion of impermeable or hard seeds, mechanical scarification, can damage seeds. Experiments were conducted to determine the effect of cultivar, year of production and storage conditions on germination and hard seed content in alfalfa. Experiments with four Canadian cultivars indicated a significant effect of cultivar on seed weight, germination and hard seed content in freshly harvested seed. Year of production had a greater influence on these seed traits than cultivar. Under uncontrolled storage conditions, germination of 35 alfalfa synthetics increased and hard seed content decreased with time, although not at the same rate for all synthetics. Storage at 20 °C for up to 64 mo did not significantly decrease hard seed content. At 35 °C, hard seed content decreased continuously for all cultivars (for one cultivar to <5%) after 64 mo. Over 80.5 mo storage at room temperature (22 ± 2 °C), germination increased in a nonlinear fashion. Storing seed in sealed plastic bags at 35 °C delayed seed dehydration and the loss of hard seeds. Levels of nonviable seed were low (<10%), even after storage at 35 °C for 64 mo. Brief (1 min) exposure to liquid nitrogen increased germination of freshly harvested alfalfa seed to >90%. The results indicate that the germination percent of alfalfa can be increased and hard seed content reduced by short exposure to liquid nitrogen or storage at nonlethal high temperatures (35 °C) such that mechanical scarification may be unnecessary. Key words: Medicago sativa, hard seed, stored seed, seed dehydration, high temperature treatment, liquid nitrogen treatment

Comparison of Procedures for Isolation of Monoterpene Hydrocarbons from Fresh Needles of Picea abies and Picea omorica

2000 ◽  
Vol 65 (7) ◽  
pp. 1073-1081 ◽  
Author(s):  
Valerie Holubová ◽  
Iva Chvílíčková ◽  
Vlastimil Kubáň
Keyword(s):  
Picea Abies ◽  
Liquid Nitrogen ◽  
Steam Distillation ◽  
Extraction Efficiency ◽  
Total Content ◽  
Storage Conditions ◽  
Fresh Weight ◽  
Hexane Extraction ◽  
Monoterpene Hydrocarbons ◽  
And Storage

Extraction procedures (steam distillation, supercritical fluid extraction and solvent extraction) for isolation of monoterpene hydrocarbons from fresh needles of Picea abies and Picea omorica were optimised. The procedures were compared with the aim of minimizing consumption of needles and improving the extraction efficiency and repeatability. An influence of homogenisation procedures and storage conditions (liquid nitrogen, -18 and 4 °C) on the total content and composition of essential oils was studied. Cryogenic grinding (liquid nitrogen) combined with the extraction with cold hexane (extraction time 2 h) and subsequent GC-MS determination in freshly homogenised needles gives the best results (1.5-4 times better extraction efficiency, RSD < 10% for P. abies and < 25% for P. omorica). Limits of detections (3 S/N) for individual monoterpene hydrocarbons from units to tens of ng/g and recoveries 97.2-101.4% were found in fresh needles (calculated to fresh weight). While cooling to 4 °C is unacceptable, freezing at -18 °C for the period of 18 days in the dark gives also good results.

Reduction of hardseededness in mungbean by short duration high temperature treatment

1992 ◽  
Vol 32 (4) ◽  
pp. 483 ◽  
Author(s):  
BC Imrie
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Short Duration ◽  
Vigna Radiata ◽  
Pilot Trial ◽  
Rotating Cylinder ◽  
Temperature Treatment ◽  
High Temperature Treatment ◽  
Hot Plate ◽  
Hard Seeds

Seeds of 2 lines of mungbean (Vigna radiata), soft-seeded cv. Berken and HS23 with 34% hard seeds, were agitated on a hot plate to determine the effects of temperatures up to 200�C on hardseededness, germination and seed variability. The results of this experiment, combined with a pilot trial using a heated rotating cylinder, showed that the temperature of 175�C for 30 s was the optimum treatment to produce seeds suitable for sprouting. This heat treatment reduced hardseededness from 34 to 1%, increased germination from 64 to 96%, and did not increase the percentage of dead seeds.

Hard-seed content of alfalfa grown in Canada

1991 ◽  
Vol 71 (2) ◽  
pp. 437-444 ◽  
Author(s):  
D. T. Fairey ◽  
L. P. Lefkovitch
Keyword(s):  
British Columbia ◽  
Geographic Location ◽  
Viable Seed ◽  
Hard Seed ◽  
Peace River ◽  
Seed Content ◽  
River Region ◽  
Hard Seeds ◽  
Viable Seeds ◽  
Production Areas

The hard-seed content of alfalfa (Medicago spp.) grown in Canada in relation to genotype and geographic location of production was surveyed for the commercial growing regions in Manitoba, Saskatchewan, Alberta and British Columbia. The average hard-seed content of all pedigreed production over a 5-yr period, ranged from 22 to 37% and that in nonpedigreed production was between 14 and 30%. A database of the five widely grown cultivars revealed that the hard-seed content of alfalfa in the most northerly growing areas in the Peace River region of Alberta and British Columbia ranged from 31 to 51%, while hard seed content of alfalfa produced elsewhere varied from 22 to 38%. There was no apparent effect of latitude on the proportion of hard seeds, while there was a small increase for two of the five cultivars in production areas further west. Of particular interest was the trend in viable seed production. There was consistent evidence suggesting that the proportion of viable seeds decreased in production areas further north, but increased in production areas further west. However, the minimum viability was always in excess of 85%. There was no correlation between hard and viable seed. Key words: Medicago spp., alfalfa, lucerne, hard seeds, viable seeds

scholarly journals First year seed softening in three Hedysarum spp. in southern Queensland

2003 ◽  
Vol 43 (11) ◽  
pp. 1303 ◽  
Author(s):  
L. W. Bell ◽  
D. L. Lloyd ◽  
K. L. Bell ◽  
B. Johnson ◽  
K. C. Teasdale
Keyword(s):  
Soil Surface ◽  
First Year ◽  
Hard Seed ◽  
Seed Content ◽  
Constant Rate ◽  
Significant Difference ◽  
Hard Seeds ◽  
Hedysarum Coronarium ◽  
Seed Characteristics ◽  
Selection Of

Seed softening was investigated in 41 lines of Hedysarum coronarium, 5 lines of H. carnosum and 8�lines of H. flexuosum grown at Oakey, Queensland in 2000. After testing for initial hard seed content in each line, the remaining hard seeds were placed on the soil surface at Kingsthorpe on 15 January 2001. Changes in hard seed levels over the ensuing summer-autumn seed softening period were measured. The initial hard seed content in each species ranged from 20 to 79% in H. coronarium; 31 to 79% in H. carnosum; and 54 to 83% in H. flexuosum. No significant difference in the time of seed softening between accessions or species was identified. Despite the similar timing, the extent of softening varied greatly between accessions and species. The proportion of initially hard seed that softened ranged from 54 to 95% in H. coronarium; 27 to 45% in H. carnosum; and 50 to 74% in H. flexuosum. Accessions of H. coronarium and H. flexuosum softened the greatest proportion of seed between 15 January and 22�February with reducing amounts thereafter. Accessions of H. carnosum softened less seed over this period, appearing to display a slower, more constant rate of softening. Although total hard seed levels were relatively low, there was sufficient variability in hard seed levels to provide some scope for selection of desired hard seed characteristics.

scholarly journals Optimizing Viable CD34 + Enumeration in Cryopreserved HPC Samples for Implementation of an External QA Program - Relevance to the Current Pandemic

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4847-4847
Author(s):  
Scott J Ragg ◽  
Annabella Chang ◽  
David Ma
Keyword(s):  
Liquid Nitrogen ◽  
Conflicts Of Interest ◽  
Cost Effective ◽  
Storage Conditions ◽  
Dry Ice ◽  
Cd34 Cells ◽  
Significant Difference ◽  
Mode Of Transport ◽  
Cost Implications ◽  
And Storage

Abstract Background The current External Quality Assurance (EQA) programs for haemopoietic progenitor cell (HPC) involve enumeration of total CD34 + cells in fixed samples, which does not align with clinical practice where analysis of viable CD34 + cells (vCD34 +) is required. The COVID-19 pandemic forced a fundamental change in the global procurement of allogeneic HPC for transplantation. To better meet the emergent challenges of transporting cryopreserved allogeneic HPC during pandemics, there is an urgent need for EQA programs to evaluate reproducibility and harmonization of vCD34 + HPC enumeration between collection and transplant centres. A successful vCD34 + EQA program will require cost-effective distribution of cryopreserved reference samples (CRS) with acceptable reproducibility and specificity. This study aims to evaluate the feasibility of distribution of CRS to participating facilities for vCD34 + enumeration using dry ice, instead of liquid nitrogen which is not suitable for CRS transport due to logistical and cost implications. Method: A 15 ml sample was cryopreserved from each of 10 HPC harvests from consented transplant donors (SVH HREC approval #10/07). Cryopreserved HPC samples were either stored on dry ice for 1-4 days, or on dry ice for one day followed by liquid nitrogen (LN 2) storage for 1-3 days to assess optimal conditions for vCD34 + EQA. For viable CD34 + measurement by flow cytometry, the single platform assay was performed using Trucount tubes containing CD45-FITC/CD34-PE and 7-AAD viability exclusion dye. The optimum transportation condition was validated in pilot and multi-center national studies which involved transport of CRS on dry ice to 12 recipient centers in 5 of the 6 Australian states. Results: Dry ice and LN 2 transport and storage conditions were simulated at the central laboratory and the vCD34 + enumerated. It was found that a combination of one day on dry ice followed by LN 2 storage stabilized the viability compared to continuous storage on dry ice. A successful pilot study confirmed the effect on vCD34 + count of shipping two CRS from central Lab to two interstate laboratories. For the national multicenter study, the transportation distances ranged from 0.5 - 4,000 km (median 513 km) with transit times ranging from 1- 26 hours (median 22.5 hours). Eight of 12 centers (67%) returned comparable results that were within ±10% of the median. There was no significant difference between samples tested immediately upon arrival or after subsequent LN 2 storage (p=0.41). There was no significant relationship between comparability of vCD34 + counts and the sample transit time (R=0.67, p=0.07) nor distance travelled (R = 0.19, p=0.55), showing that laboratory outcome was unrelated to sample transport. Conclusion: Dry ice distribution of cryopreserved HPC for up to 26 hours results in a stable CRS. The estimated cost of safer and more convenient dry ice delivery is &gt;20-fold lower than LN 2. This feasibility study illustrates that an EQA utilizing this mode of transport and storage of CRS is suitable for inter-facility harmonization and standardization forming the basis of an EQA programs for vCD34 + HPC enumeration. Disclosures No relevant conflicts of interest to declare.

Barley seed storage under controlled conditions

2019 ◽  
pp. 140-150 ◽  
Author(s):  
O. A. Zadorozhna ◽  
T. P. Shyianova ◽  
M.Yu. Skorokhodov
Keyword(s):  
Hordeum Vulgare ◽  
Moisture Content ◽  
Spring Barley ◽  
Seed Storage ◽  
Growing Season ◽  
Storage Conditions ◽  
Meteorological Conditions ◽  
Hordeum Vulgare L ◽  
The Relationship ◽  
And Storage

Seed longevity of 76 spring barley gene pool samples (Hordeum vulgare L. subsp. distichon, convar. distichon: 56 nutans Schubl., two deficience (Steud.) Koern., two erectum Rode ex Shuebl., two medicum Koern.; convar. nudum (L.) A.Trof.: one nudum L. та subsp. vulgare: convar. vulgare: nine pallidum Ser., three rikotense Regel.; convar. coeleste (L.) A.Trof.: one coeleste (L.) A.Trof.) from 26 countries, 11 years and four places of reproduction was analyzed. Seeds with 5–8% moisture content were stored in chamber with unregulated and 4oC temperature. The possibility of seed storage under these conditions for at least 10 years without significant changes in germination has been established. The importance of meteorological conditions in the formation and ripening of seeds for their longevity is confirmed. The relationship between the decrease of barley seeds longevity and storage conditions, amount of rainfall, temperature regime during the growing season of plants is discussed.

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