scholarly journals Seed Biologists Beware: Estimates of Initial Viability Based on Ungerminated Seeds at the End of an Experiment May Be Error-Prone

2021 ◽  
Author(s):  
Byron B. Lamont
Keyword(s):  
Seed Viability ◽  
Separate Sample ◽  
Prolonged Duration ◽  
Germination Success

Seed viability is routinely measured on seeds that fail to germinate at the end of an experiment. Together with the number of germinants, this is used to estimate viability of the seeds at start of the experiment (i.e., initial viability) and provides the comparative basis on which germination success is determined. Perusal of the literature shows that sometimes (perhaps often, as the problem has yet to be recognized or reported) prolonged duration in the treatment, especially the control where little germination occurs, can lead to loss of viability. This results in underestimation of initial viability if that treatment is used. I caution against the routine use of end-of-trial germination and viability of ungerminated seeds as an estimate of initial viability in determining germination success of various treatments. I explore ways to deal with the problem but the preference is for estimates of initial viability to be undertaken on a separate sample of seeds concurrently with the experiment as this avoids the risk of seed death during the trial.

scholarly journals Seed Biologists Beware: Estimates of Initial Viability Based on Ungerminated Seeds at the End of an Experiment May Be Error-Prone

2021 ◽  
Author(s):  
Byron B. Lamont
Keyword(s):  
Seed Viability ◽  
Separate Sample ◽  
Prolonged Duration ◽  
Germination Success

Seed viability is routinely measured on seeds that fail to germinate at the end of an experiment. Together with the number of germinants, this is used to estimate viability of the seeds at start of the experiment (i.e., initial viability) and provides the comparative basis on which germination success is determined. Perusal of the literature shows that sometimes (perhaps often, as the problem has yet to be recognized or reported) prolonged duration in the treatment, especially the control where little germination occurs, can lead to loss of viability. This results in underestimation of initial viability if that treatment is used. I caution against the routine use of end-of-trial germination and viability of ungerminated seeds as an estimate of initial viability in determining germination success of various treatments. I explore ways to deal with the problem but the preference is for estimates of initial viability to be undertaken on a separate sample of seeds concurrently with the experiment as this avoids the risk of seed death during the trial.

scholarly journals Seed Biologists Beware: End-of-Trial Estimation of Initial Viability May Be Error-Prone Due to Unexpected Seed Death during the Experiment

2021 ◽  
Author(s):  
Byron B. Lamont ◽  
Rosemary J. Newton ◽  
Pablo Gomez-Barreiro ◽  
Tianhua He
Keyword(s):  
Cold Storage ◽  
Standard Procedure ◽  
Seed Viability ◽  
Separate Sample ◽  
Annual Loss ◽  
Order Of Magnitude ◽  
Germination Success ◽  
Initial Seed ◽  
Different Levels

Seed viability is routinely measured on seeds that fail to germinate at the end of an experiment. Together with the number of germinants, this is used to estimate viability of the seeds at start of the experiment (i.e., initial viability) and provides the comparative basis on which germination success is determined. We used this standard procedure on 40 Leucadendron species subjected to oscillating temperatures, heat and/or smoke pre-treatments to examine the extent to which they raised germination levels above that of the untreated controls. 16 species showed significantly different levels of estimated initial seed viability between treatments when they should have been unaffected. Loss of viability during the trial was an order of magnitude greater than annual loss during cold storage, which was usually negligible. Lowest levels of estimated initial viability occurred among the poorly germinating controls and confirmed that the heat and smoke treatments had little effect on viability. Species with soil-stored seeds were more vulnerable to this artefact than those with plant-stored seeds. We caution against the routine use of end-of-trial germination and viability of ungerminated seeds as an estimate of initial viability in determining germination success of various treatments. The preference is for estimates of initial viability to be undertaken on a separate sample of seeds in association with the trial.

scholarly journals How Does Ocean Acidification Affect the Early Life History of Zostera marina? A Series of Experiments Find Parental Carryover Can Benefit Viability or Germination

2021 ◽  
Vol 8 ◽  
Author(s):  
Alyson Lowell ◽  
Eduardo Infantes ◽  
Laura West ◽  
Lauren Puishys ◽  
Claudia E. L. Hill ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Zostera Marina ◽  
Seed Quality ◽  
Global Climate ◽  
Seed Viability ◽  
Early Life History ◽  
Western Coast ◽  
Seagrass Meadows ◽  
Germination Success ◽  
Development Outcomes

Elevated partial pressure of carbon dioxide (pCO2) as a concomitant of global climate change may facilitate the establishment of future seagrass meadows and subsequently its benefit could be incorporated into techniques to increase restoration success. In five manipulative experiments, we determined how increased CO2 affects the maturation of flowers, and the development of seeds and seedlings for the foundation species Zostera marina. Experiments tested the development from both seeds collected from non-treated flowering shoots (direct) and seeds harvested from flowering shoots after CO2 exposure (parental carryover). Flowering shoots were collected along the western coast of Sweden near the island of Skafto. The seeds produced were used in experiments conducted at Kristineberg, Sweden and Dauphin Island, AL, United States. Experiments varied in temperature (16, 18°C) and salinity (19, 33 ppt), as well as duration and magnitude of elevated CO2 exposure. Environmental conditions among experiments, such as temperature (16, 18°C) and salinity (19, 33 ppt), as well as duration and magnitude of pCO2 exposure differed. Flowering maturation, spathe number, seed production, and indicators of seed quality did not appear to be affected by 39–69 days of exposure to CO2 conditions outside of natural variability (pCO2 = 1547.2 ± 267.60 μatm; pHT = 7.53 ± 0.07). Yet, seeds produced from these flowers showed twofold greater germination success. In another experiment, flowering shoots were exposed to an extreme CO2 condition (pCO2 = 5950.7 ± 1,849.82 μatm; pHT = 6.96 ± 0.15). In this case, flowers generated seeds that demonstrated a fivefold increase in an indicator for seed viability (sinking velocity). In the latter experiment, however, germination appeared unaffected. Direct CO2 effects on germination and seedling production were not observed. Our results provide evidence of a parental CO2 effect that can benefit germination or seed viability, but early benefits may not lead to bed establishment if other environmental conditions are not well suited for seedling development. Outcomes have implications for restoration; CO2 can be supplied to flowering shoot holding tanks to bolster success when the purpose is to redistribute seeds to locations where beds are extant and water quality is adequate.

scholarly journals Seed viability and germination success of Acacia tortilis along land‐use and aridity gradients in the Eastern Sahara

2015 ◽  
Vol 6 (1) ◽  
pp. 256-266 ◽  
Author(s):  
Gidske Leknæs Andersen ◽  
Knut Krzywinski ◽  
Håkon K. Gjessing ◽  
Richard Holton Pierce
Keyword(s):  
Land Use ◽  
Seed Viability ◽  
Acacia Tortilis ◽  
Germination Success

Germination of Lomandra sonderi (Dasypogonaceae) Promoted by Pericarp Removal and Chemical-Stimulation of the Embryo

1995 ◽  
Vol 43 (2) ◽  
pp. 223 ◽  
Author(s):  
JA Plummer ◽  
AD Crawford ◽  
SK Taylor
Keyword(s):  
Culture Medium ◽  
Seed Viability ◽  
Limiting Factors ◽  
Eucalyptus Marginata ◽  
Liquid Culture Medium ◽  
Embryo Dormancy ◽  
Germination Success ◽  
Common Genus ◽  
Excised Embryos

Lomandra Labill. is a common genus in the understorey of the jarrah (Eucalyptus marginata Sm.) forest of Western Australia. Species in this genus are difficult to propagate by seed and do not readily re establish following mining. Limiting factors for germination success were explored and identified. Lomandra sonderii (F.Muell.) Ewart set very few seed (seeds per flower = 0.122). Tetrazolium tests indicated that seed viability was relatively high (50%). Germination was inhibited (0%) by the inner pericarp tissues which surround the seed and are part of the diaspore. Manual removal of the inner pericarp or leaching overcame this inhibition with a fifth of seeds subsequently germinating. Similar treatments improved germination of L. drummondii (F. Muell. ex Benth.) Ewart from 40% to 80%. Soaking L. sonderi seeds in gibberellic acid (GA3, 50 mg L-1) further improved germination (28%). Ants (Camponotus sp. and Iridomyrmex sp.) collected and dispersed L. sonderi seed and are likely to improve germination in the forest by removing and consuming the inner pericarp. Only half of the Viable excised embryos of L. sonderi grew in vitro, indicating the presence of embryo dormancy. Embryo dormancy was overcome by GA3 (0.5 mM) and zeatin (0.5 mM) in the liquid culture medium. In vitro culture may be a practical means of propagating Lomandra if seed is scarce.

Determining the factors affecting seed germination in Livistona australis (Arecaceae) for the recovery of fragmented populations

2012 ◽  
Vol 60 (7) ◽  
pp. 575 ◽  
Author(s):  
Nicholas Carlile ◽  
David Priddel ◽  
Tony D. Auld ◽  
David A. Morrison
Keyword(s):  
Seed Germination ◽  
Seedling Recruitment ◽  
Seed Viability ◽  
Factors Affecting ◽  
Light Levels ◽  
In Situ Experiments ◽  
Germination Success ◽  
Buried Seed ◽  
Potential Success

Understanding seed germination and seedling recruitment is important for managing long-lived plant species, particularly palms that are transplanted from the wild and where regeneration is suppressed by seed predators and exotic herbivores. Seed viability, the timing of germination, and the factors influencing germination were investigated for the cabbage tree palm, Livistona australis (R.Br.) Mart. Greenhouse studies were combined with in situ experiments conducted on the Australian mainland and on a nearby mammal-free island. Under greenhouse conditions, >90% of seed germinated within 4 months. In the field, burial rather than surface sowing of seed increased germination success. Seed without mesocarp and in sunlight had increased germination when compared with fruits in shade on the island, whereas neither presence/absence of mesocarp or light levels had any effect on the mainland. Germination success was substantially lower on the mainland, primarily because of high seed predation from the native bush rat, Rattus fuscipes. When caged to exclude vertebrates, 44% of seed were damaged over time by pathogens and invertebrates, with losses greater in sunlight than in shade. Results from the present study indicate that freshly buried seed with the mesocarp removed would have the greatest potential success in promoting the restoration of L. australis at degraded sites.

Methods for rapid determination of pecan (Carya illinoensis) seed viability

2017 ◽  
Vol 45 (2) ◽  
pp. 455-464
Author(s):  
T.T. Xue ◽  
J. Liu ◽  
Y.B. Shen ◽  
G.Q. Liu
Keyword(s):  
Rapid Determination ◽  
Seed Viability ◽  
Carya Illinoensis

CLINICAL INVESTIGATIONS OF A LONG-ACTING OESTRIOL (POLYOESTRIOL PHOSPHATE)

1961 ◽  
Vol 38 (1) ◽  
pp. 73-87 ◽  
Author(s):  
Christian Lauritzen ◽  
Semih Velibese
Keyword(s):  
Side Effects ◽  
Phosphoric Acid ◽  
Quantitative Data ◽  
Water Soluble ◽  
Cholesterol Concentration ◽  
Experimental Investigations ◽  
Clinical Investigations ◽  
Prolonged Duration ◽  
High Doses ◽  
Long Acting

ABSTRACT A description is given of experimental investigations and preliminary clinical experience with the long-acting oestriol compound polyoestriol phosphate – a water-soluble polymere of oestriol and phosphoric acid. The compound seems to exert all the physiologically important effects of oestriol. Even with high doses the hormone causes no proliferation of the endometrium and no withdrawal bleeding. It has no untoward effect on metabolism. It decreases slightly the cholesterol concentration (to the extent of ⅓–⅕ of the effect produced by long-acting oestradiol esters). The compound has a wide therapeutic range. No side-effects have been observed. Doses of 10 mg or more have a prolonged duration. Additional prolongation of the effect is largely dependent on dosage. To ensure an effect lasting for 4 weeks 40 mg polyoestriol phosphate (corresponding with 30 mg oestriol) is required – an amount which roughly corresponds with physiological quantitative data. The compound, which involves an interesting new principle of prolongation, was most effectively used in the treatment of menopausal symptoms and genital organic disorders. For these indications it can be recommended without reservation.

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