Does lignum rely on a soil seed bank? Germination and reproductive phenology of Muehlenbeckia florulenta (Polygonaceae)

2005 ◽  
Vol 53 (5) ◽  
pp. 407 ◽  
Author(s):  
Caroline Chong ◽  
Keith F. Walker
Keyword(s):  
Vegetative Growth ◽  
Soil Seed Bank ◽  
Seed Viability ◽  
South Australia ◽  
Reproductive Phenology ◽  
Continuous Darkness ◽  
Murray Darling Basin ◽  
Droughts And Floods ◽  
Viable Seeds ◽  
And Storage

Tangled lignum (‘lignum’) is a dioecious, multi-stemmed woody shrub that is common in flood-prone areas of inland Australia, including the Murray–Darling Basin. It is often leafless during dry periods, but maintains vegetative growth by stem layering, and responds rapidly to rainfall or flooding by production of shoots, leaves and flowers. This study considers the viability of lignum seeds (contained in achenes) under various conditions of temperature, light, moisture and storage or burial. The seeds are not innately dormant, and germinate within 14 days under ideal conditions. From 66 to 86% of fresh and dry-stored seeds germinate in fluctuating temperatures (15°C/5°C, 24°C/10°C, 31°C/15°C), and optimally at 24°C/10°C, given moisture and light. They also germinate in water (56% success), and remain buoyant for 5–25 days. Germination is inhibited by constant temperatures of 12 and 24°C (4.0–4.8% success) and continuous darkness (6.0–56.0% success), but increases on return to light. Seed viability is depressed by 10% after 70-day dry storage and by 48% after 92-day burial in soil over winter. In one year’s (2002) observations of a population on the River Murray floodplain near Morgan, South Australia, winter- and spring-seeding plants produced viable seeds 14–30 days after anthesis, and although rainfall in winter (July) produced a pulse of seedlings, none became established. Achenes were shed soon after maturation, but soil samples revealed very few germinable seeds. It therefore appears that the seeds do not persist for long on the mother plant or in the soil. The persistence of lignum in environments prone to erratic droughts and floods appears to depend mainly on its capacity to tolerate drought, maintain vegetative growth and respond quickly to watering.

scholarly journals Longevidad y germinación de semillas de Syagrus romanzoffiana (Arecaceae) y sus implicaciones ecológicas

2015 ◽  
Vol 63 (2) ◽  
pp. 333 ◽  
Author(s):  
Túlio Gabriel Soares Oliveira ◽  
Anderson Cleiton José ◽  
Leonardo Monteiro Ribeiro ◽  
José Marcio Rocha Faria
Keyword(s):  
Seed Bank ◽  
Soil Seed Bank ◽  
Seedling Emergence ◽  
Seed Viability ◽  
Palm Tree ◽  
Forest Fragment ◽  
Seedling Mortality ◽  
Viable Seeds ◽  
One Year ◽  
Syagrus Romanzoffiana

<strong><em>Syagrus romanzoffiana</em> is a palm tree native and widely distributed of South America.</strong> <strong>The present study investigated the longevity and germination of the buried seeds of this species in an experimental seed bank.</strong> <strong>Laboratory germination and</strong> <strong>viability tests were performed for comparison with field results. Pyrenes (seeds enclosed by the endocarp) were buried in a forest fragment edge in July (dry season) in July 2012 and exhumed monthly during one year, for the assessment of water content</strong> <strong>and percentage of germinated and viable seeds.</strong> <strong>Germination tests</strong> <strong>were conducted in a Mangelsdorf-type germinator at 30°C under constant light and the viability was </strong><strong>assessed by the tetrazolium test. An additional sample of</strong> <strong>pyrenes was buried to evaluate the percentage of seedling emergence and survival. Climatic</strong> <strong>and soil moisture</strong> <strong>data</strong> <strong>were recorded.</strong> <strong>In the laboratory, the pyrenes were stored for one year in a temperature-controlled room at 20ºC and 75% (±10%) relative air humidity to assess changes in the percentage of germination and viability over time.</strong> <strong>In the field, a reduction in seed viability</strong> <strong>was observed over the study period, with a total loss of viability of non-germinated seeds at seven months after burial.</strong> <strong>The maximum germination (close to 26%) was observed in the samples that were exhumed between five and seven months after burial. In the field, seedling emergence did not exceed 10% and seedling mortality was not observed. The percentages of germination and of viable seeds decreased both in burial and stored seeds. The stored seeds maintained viability at up to six months, with marked reduction thereafter. After the germination tests (four months) in the laboratory, all of the remaining seeds were nonviable. The ecological, physiological</strong> <strong>and reproductive characteristics of the species are discussed, and we concluded that</strong> <strong><em>S. romanzoffiana</em></strong> <strong>seeds have short longevity after imbibition, and low potential for soil seed bank formation.</strong>

scholarly journals Storage in cerrado soil and germination of Psychotria vellosiana (Rubiaceae) seeds

2006 ◽  
Vol 66 (2b) ◽  
pp. 709-717 ◽  
Author(s):  
C. G. Araújo ◽  
V. J. M. Cardoso
Keyword(s):  
Seed Bank ◽  
Storage Time ◽  
Soil Seed Bank ◽  
Seed Viability ◽  
Limiting Factor ◽  
Ecological Aspects ◽  
Different Depths ◽  
Persistent Soil Seed Bank ◽  
Viable Seeds

The regeneration of plant communities from seed depends, to a large extent, on the capacity of the seed remaining viable in the soil. The viability and germination of artificially buried Psychotria vellosiana seeds in cerrado soil were studied, with the purpose of discovering some physio-ecological aspects of dispersed seeds and evaluating their potential to constitute a soil seed bank. Seed samples were placed in nylon envelopes and buried in the soil of a Cerrado reserve at two different depths and sites. Buried seeds were retrieved periodically and tested for germination along with dry-stored seeds. In general, there was a reduction in seed germination with storage time, both in soil and dry stored conditions, and in some assays exhumed seeds germinated faster than dry stored ones. In general the soil storage favoured seed viability of ungerminated seeds as compared to dry stored ones, with the seeds remaining partially viable after 10 months of storage. The lack of germination of viable seeds suggests that seeds showed true dormancy and/or required an extended time to germinate. It was observed that some seeds had germinated while buried and such in situ germination tended to increase with rainfall. The water availability in the soil might be a limiting factor for successful germination of P. vellosiana in the field, and the seeds may constitute a persistent soil seed bank in the cerrado as dispersed seeds remain viable in the soil until the following period of seed dispersal.

Impact of post-anthesis glyphosate on woolly cupgrass seed production, seed weight and seed viability

2015 ◽  
Vol 95 (6) ◽  
pp. 1193-1197 ◽  
Author(s):  
Robert E. Nurse ◽  
Stephen J. Darbyshire ◽  
Marie-Josée Simard
Keyword(s):  
Seed Production ◽  
Seed Weight ◽  
Soil Seed Bank ◽  
Seed Viability ◽  
Leaf Sheath ◽  
Embryo Viability ◽  
Weed Growth ◽  
Woolly Cupgrass ◽  
Eriochloa Villosa ◽  
Viable Seeds

Nurse, R. E., Darbyshire, S. J. and Simard, M.-J. 2015. Impact of post-anthesis glyphosate on woolly cupgrass seed production, seed weight and seed viability. Can. J. Plant Sci. 95: 1193–1197. Herbicides are generally applied at early stages of crop and weed growth to protect crop yield. Few studies have evaluated the effect of late (post-anthesis) applications of glyphosate as a management option to limit the seed production of weed escapes, such as woolly cupgrass (Eriochloa villosa). We propagated woolly cupgrass under greenhouse conditions and then applied three glyphosate treatments post-anthesis including: (1) an untreated control; (2) 900 g a.e. ha−1; and (3) 1800 g a.e. ha−1. Terminal inflorescences were collected 21 d after glyphosate application, and seed production, seed weight and embryo viability were assessed. Post-anthesis glyphosate applications did not influence seed production, but reduced seed weight and viability by 50 and 96%, respectively. Therefore, glyphosate applied just before the woolly cupgrass inflorescence begins to emerge from the leaf sheath (as late as the R1 stage in soybeans) is an effective strategy to manage woolly cupgrass reproduction and stop viable seeds from entering the soil seed bank or other dispersal pathways.

Reproductive biology of the endangered Brachycome muelleri (Asteraceae), an endemic herb of Eyre Peninsula, South Australia

2003 ◽  
Vol 51 (2) ◽  
pp. 179 ◽  
Author(s):  
Manfred Jusaitis ◽  
Birgitte Sorensen ◽  
Lesley Polomka
Keyword(s):  
Seed Dispersal ◽  
Seed Production ◽  
Reproductive Biology ◽  
Field Experiments ◽  
Soil Seed Bank ◽  
Seed Viability ◽  
South Australia ◽  
Soil Surface ◽  
Long Distance ◽  
Pollinator Visitation

The reproductive biology of Brachycome muelleri Sonder (Asteraceae) was studied from 1995 to 1997 by using nursery and field experiments. Reproductive development and seed dispersal occupied approximately half of the 4-month growth cycle. Flowers of B. muelleri did not have any obvious self-incompatibility systems and were readily selfed to produce viable seed. It appeared that B. muelleri may be preferentially cross-pollinated under ideal conditions of pollinator visitation, but could revert to self-pollination in the event of outcross failure. Seed dispersal was assisted by the epinastic curvature of peduncles as fruit matured, bringing capitula into contact with the soil a short distance away from the parent plant. Slight wind-stimulated movement of the capitulum was sufficient to dislodge seed directly onto the soil surface. Seed was shed in the immediate vicinity of parent plants and although some short-range movement facilitated by rain splash, water flow and gravity was observed, no long-distance dispersal mechanisms were apparent. Annual seed production of the single extant population of B. muelleri in South Australia was estimated at about 5 million seeds. Immediately after dispersal, the soil seed bank in the vicinity of B. muelleri plants contained, on average, over 1700 germinable seeds m–2. Many of these seeds germinated or died within a year, the remainder persisting into a second or third year. Seed viability under field-burial conditions declined to less than 10% over that time. Population size did not appear to be limited by seed production, but rather by seed dispersal syndrome.

scholarly journals Carbohydrate Depletion and Leaf Blackening in Protea neriljiolia

1991 ◽  
Vol 116 (6) ◽  
pp. 1019-1024 ◽  
Author(s):  
Robyn McConchie ◽  
N. Suzanne Lang ◽  
Ken C. Gross
Keyword(s):  
Sink Strength ◽  
Cut Flower ◽  
Continuous Darkness ◽  
Primary Stress ◽  
Leaf Carbohydrates ◽  
Carbohydrate Depletion ◽  
Sink Demand ◽  
And Storage ◽  
Exogenous Sugar ◽  
Storage Reserves

Leaf blackening on cut flower Protea nerii[olia R. Br. stems was dramatically reduced under a 12-hour photosynthetic light period (120 μmol·m-2·s-1) at 25C for 15 days compared with stems kept in the dark. In the light, addition of 0.5% exogenous sugar to the vase solution resulted in a maximum of 2.5% leaf blackening, while stems with no exogenous sugar had a maximum of 16.5%. Continuous darkness resulted in 94% leaf blackening by day 7, irrespective of sugar treatment. Starch and sucrose concentrations were markedly lower in leaves on dark-held stems than in leaves on stems held in the light; thus, carbohydrate depletion could be the primary stress that initiates leaf blackening. In the light, rates of carbon exchange and assimilate export were similar, indicating that the amount of carbon fixed maybe regulated by sink demand. The pattern of carbon partitioning changed in light-held leaves of the 0% sugar treatment during rapid floral expansion and senescence. Inflorescence expansion appears to influence partitioning of photoassimilates and storage reserves into transport carbohydrates; under decreased sink demand, the assimilate export rate decreases and photoassimilates are partitioned into starch. The data suggest that sink strength of inflorescences held in darkness may be responsible for the depletion of leaf carbohydrates and. consequently, blackening.

scholarly journals Conservation survey, condition report and collections care proposal for the World War I portrait collection at State Records of South Australia

2021 ◽  
Author(s):  
Sarah Ann Ernisse
Keyword(s):  
World War I ◽  
South Australia ◽  
World War ◽  
Advantages And Disadvantages ◽  
The World ◽  
Detailed List ◽  
Collections Care ◽  
And Storage ◽  
State Records

This practical thesis project report contains a conservation survey, condition report and collections care proposal for the World War I portrait collection at State Records of South Australia. The plan prescribes immediate, short term and long term recommendations for the improvement of preservation techniques for the World War I collection. The paper also contains information and results gathered through the condition report of the collection sample and conservation survey. The survey investigated the current environment and storage facilities, access, security and disaster planning surrounding the collection. The paper also outlines the practices and methodologies of the applied thesis for both the conservation survey and condition report. The collection care proposal assesses current practices in order to provide State Records with accurate goals that offer flexible options. A detailed list of housing recommendations is included in the proposal; an advantages and disadvantages assessment if included for each option to help State Records better fit its needs and abilities in the future. Charts showing the results of the condition report and environmental assessment from the conservation survey are included in the appendix for further reference. This project is intended to draw attention to the urgent need for better preservation practices for the World War I portrait collection.

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.

Seed storage and germination studies of Garcinia talbotii Raizada ex Santapau seeds - an endemic tree from Western Ghats of India

2016 ◽  
Vol 23 (2) ◽  
pp. 73-78
Author(s):  
T. Sabu ◽  
P.S. Shameer ◽  
Chitra Rajeswary ◽  
N. Mohanan ◽  
C. Anilkumar
Keyword(s):  
Ex Situ Conservation ◽  
Storage Temperature ◽  
Seed Viability ◽  
Seed Storage ◽  
Ex Situ ◽  
Hermetic Storage ◽  
Western Ghats Of India ◽  
Relationship Of ◽  
The Relationship ◽  
And Storage

Seeds of Garcinia talbotii remained viable hardly for two weeks in open room conditions. As part of ex-situ conservation of Garcinia talbotii, seeds longevity was studied since seeds are the main propagule. For this, the relationship of seed viability with respect to different moisture content and storage temperature were analyzed. Seed storage behaviour is also investigated. Being recalcitrant, seeds are desiccation sensitive as well as chilling sensitive. During hermetic storage of seeds at 300C /70 % RH seeds retained viability about 6 months.

scholarly journals Effect of desiccation temperature on viability of immature dandelion (Taraxacum agg.) seeds dried in mowed inflorescences

2010 ◽  
Vol 56 (No. 12) ◽  
pp. 580-583 ◽  
Author(s):  
Z. Martinková ◽  
A. Honěk
Keyword(s):  
Seed Dispersal ◽  
High Temperatures ◽  
Seed Viability ◽  
Late Summer ◽  
Seed Maturation ◽  
Ripe Seed ◽  
Viable Seeds

After flowering has ceased, dandelion (Taraxacum agg.) capitula close to enable maturation of seeds. In late summer the period of seed maturation lasts for 9 days. The capitula mowed later than 4 days after the start of this period and desiccated at 25&deg;C produce viable seeds. If cut and prostrated on insolated ground inflorescences can experience temperatures exceeding 50&deg;C which may impair seed viability. We determined the effect of desiccation temperature (5, 15, 25, 35, 45 or 55&deg;C) on viability of ripening seeds using inflorescences harvested on September 5, 2008 at Prague-Ruzyne (50&deg;05'N, 14&deg;18'09 E), five days after flowering ceased (about 4 days before seed dispersal). As control, ripe seeds were collected at dispersal on the same day and desiccated at identical temperatures. Desiccated seeds were germinated at constant 17&deg;C. Ripening seeds of maturing capitula only remained germinable if desiccation temperatures were &le; 35&deg;C (optimum 25&deg;C) and were killed at 45 and 55&deg;C. The viability of ripe seed was not affected by any of the desiccation temperatures. Time of germination of 50% seeds that germinated was significantly shorter in ripe than ripening seeds. Exposure of mowed dandelion inflorescences on insolated ground (solarization) may thus decrease production of viable seeds because of high temperatures experienced during desiccation. &nbsp;

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