scholarly journals Germination requirements of the subordinate fen meadow species Valeriana dioica L

2019 ◽  
Vol 54 (1-2) ◽  
pp. 125-138 ◽  
Author(s):  
Leonid Rasran ◽  
Cornelia Eisenmann ◽  
Regina Wagentristl ◽  
Karl-Georg Bernhardt
Keyword(s):  
Morphological Variability ◽  
Regeneration Niche ◽  
Life Strategy ◽  
Cold Stratification ◽  
Calcareous Fens ◽  
High Germination ◽  
Germination Success ◽  
Pre Treatment ◽  
Early Establishment ◽  
Fen Meadow

AbstractPlant species of the intermediate life strategy type are characteristic for species-rich grasslands, which are sensitive to changes in the level of disturbance. Germination and early establishment of seedlings is expected to be the most crucial stage, limiting the successful colonization of appropriate sites. Valeriana dioica is a typical plant of calcareous fens, which are dependent on regular suppression of strong competitors by means of moderate land use. It is endangered in many parts of Central Europe, including Lower Austria. We studied the effects of light, temperature and pre-treatment (cold stratification) on the germination success of V. dioica seeds and the role of litter produced by different competitors on the early establishment of seedlings. We tested seeds from five populations differing in the level of competition for light and considered also the morphological variability of propagules and maternal plants. We found that V. dioica is able to germinate without light. It showed high germination percentages both under high summer temperatures independent of cold stratification and at low temperatures, but only after the stratification. Litter produced by dicotyledonous forbs was less hampering for the seedlings than that of small sedges or grasses. Valeriana dioica possesses a broad regeneration niche and is able to use gaps for germination and establishment both in spring and in summer. It reproduces successfully in herb-dominated fen meadow vegetation but disappears from reed communities. This study demonstrates the significant plasticity of the regeneration niche for a species with an intermediate life strategy and also stresses the importance of gaps for its reproduction.

Differences in germination response to smoke and temperature cues in ‘pyrophyte’ and ‘pyrofuge’ forms of Erica coccinea (Ericaceae)

2018 ◽  
Vol 27 (8) ◽  
pp. 562 ◽  
Author(s):  
Jenny Leonard ◽  
Adam G. West ◽  
Fernando Ojeda
Keyword(s):  
South African ◽  
Incubation Temperature ◽  
Fire Regimes ◽  
Smoke Exposure ◽  
The South ◽  
Natural Fire ◽  
Germination Response ◽  
High Germination ◽  
Germination Success ◽  
In Fire

Many plants in fire-prone ecosystems produce seeds that are cued to germinate after fire. However, fire is not uniform in the landscape, and there are often refugia where fire does not reach, like rocky outcrops or moist valleys. Erica coccinea, a heath shrub from the South African fynbos, has two distinct pyrophyte forms (a resprouter and a seeder) as well as a ‘pyrofuge’ form that only occurs in fire refugia. We measured germination response to smoke and incubation temperature in seeds from pyrophyte (resprouter and seeder) and pyrofuge populations to determine whether these forms responded differently to a fire-cue (smoke) and a general germination cue (temperature). We found that seeds from pyrofuge plants had high germination success (80.9–92.0%) at the lowest incubation temperature (15/8°C 12h day/night cycle) regardless of smoke exposure. In contrast, seeds from pyrophytes (resprouters and seeders) responded strongly to the smoke cue (71.2–95.0%) and were not as limited by temperature. These results show that fire presence and absence is driving divergence of the primary germination cue in Erica coccinea. Given the patchiness of many natural fire regimes worldwide, we expect there may be pyrofuge populations exhibiting a similar divergence of traits in other species and other fire-prone ecosystems.

Degree of fragmentation and population size do not adversely affect reproductive success of a rare shrub species, Banksia nivea (Proteaceae), in a naturally fragmented community

2019 ◽  
Vol 191 (2) ◽  
pp. 261-273 ◽  
Author(s):  
Rujiporn Thavornkanlapachai ◽  
Margaret Byrne ◽  
Colin J Yates ◽  
Philip G Ladd
Keyword(s):  
Population Size ◽  
Fruit Set ◽  
Medium Size ◽  
Fragmented Landscape ◽  
Pollinator Visitation ◽  
High Germination ◽  
Germination Success ◽  
Landscape System ◽  
Density Population ◽  
Degree Of Fragmentation

Abstract Fragmentation of plant communities is generally considered to be detrimental to the survival of the constituent species, especially those that are rare. We investigated the effects of fragmentation on reproductive biology in nine populations of the rare taxon Banksia nivea subsp. uliginosa, differing in size and habitat context. Small mammals were the main pollinator, with lower contributions from honeybees and birds (honeyeaters). There was no significant relationship between population size, fruit set and seed germinability. Fruit set was marginally highest (25.5 ± 3.4) in medium size populations and was variable over years. Lower fruit set (1.0 ± 0.6) in the smallest population may be due to inbreeding depression or lack of pollinators in a degraded habitat, but low fruit set was also observed in the largest population despite high levels of gene flow, possibly due to low pollinator visitation rate in a low-density population. Seeds from all populations had high germination success (>93.4%). Predation occurred in up to 56% of fruit and increased with increasing population size, but was not significantly different between populations of different size. Our study provided evidence that the reproductive output in species in a naturally fragmented landscape system may be resilient to reduced population size and other influences of anthropogenic fragmentation.

Dispersal and germination syndromes of tree seeds in a monsoonal forest in northern India

2005 ◽  
Vol 15 (1) ◽  
pp. 29-42 ◽  
Author(s):  
R.C. Thapliyal ◽  
S.S. Phartyal
Keyword(s):  
Seed Germination ◽  
Seed Storage ◽  
Germination Percentage ◽  
Cold Season ◽  
Poor Quality ◽  
Northern India ◽  
High Germination ◽  
Monsoon Forest ◽  
Mean Germination Time ◽  
Pre Treatment

This paper describes the dispersal–germination characteristics of seeds of 77 native tree species in a seasonal monsoon forest in Uttaranchal state, northern India. Results indicate that 50% of the species dispersed in the hot, dry summer months, 18% during the rainy season, 23% during the cold season and the remainder in late spring. Germination tests on fresh and laboratory-stored seeds revealed a relationship between morphological features of the fruit and both germination percentage and mean germination time (MGT). Highest mean germination (50%) was for dry-dehiscent fruits with winged wind-dispersed seeds, followed by dry-dehiscent fruits with non-winged seeds (38%) and seeds of dry-indehiscent fruits (37%). Lowest germination (29%) was for seeds from fleshy or pulpy fruits. MGT followed the reverse course. Germination data for seeds stored dry in the laboratory during one seeding cycle indicated six patterns of seed germination: (1) average germination percentage of fresh seeds lower than that of stored seeds, indicating an after-ripening requirement; (2) initial high germination percentage followed by low values, indicating a steep to moderate decline in viability following harvest; (3) no germination after 1 or 2 months of seed storage, due to complete loss of viability, indicating short seed longevity; (4) fresh seed germination in some species equalled the average germination value of stored seeds, indicating constant germination for one whole seeding cycle; (5) germination of both fresh and stored seeds remained consistently low throughout the season, indicating a requirement for some kind of pre-treatment or having poor quality of seeds; (6) initial high germination followed by decline and again increase, showing a seasonal rhythm of germination.

scholarly journals Effect of pre-germinative treatments on Nothofagus glauca seed germination and seedling growth

2019 ◽  
Vol 49 ◽  
Author(s):  
Ángel Cabello ◽  
Nicolás Espinoza ◽  
Sergio Espinoza ◽  
Antonio Cabrera ◽  
Rómulo Santelices
Keyword(s):  
Seed Germination ◽  
Gibberellic Acid ◽  
Seedling Growth ◽  
Iucn Red List ◽  
Cold Stratification ◽  
Natural Forests ◽  
Sowing Time ◽  
High Germination ◽  
Thiourea Solution ◽  
Quality Stock

Background: Nothofagus glauca (Phil.) Krasser (Nothofagaceae, “Hualo”) is an endemic tree of the Mediterranean zone of Chile. The natural forests in this area have been severely fragmented as a result of human causes such as replacement by agricultural crops and fast-growing tree species. From 1975, these forests have declined from 900,000 ha to 145,000 ha, so it is categorised on the IUCN Red List as ‘vulnerable’. In restoring this ecosystem, efforts should focus, in part, on the propagation of quality stock. However, information on propagation systems is still insufficient. Methods: We aimed to analyse the effect of different pre-germinative treatments and sowing times on seed germination, and seedling growth and quality. The pre-germinative treatments were: (i) cold stratification; (ii) soaking in gibberellic acid (GA3) and thiourea solution; and (iii) nursery cultivation, while the sowing times were July, August and September. Results: A high germination capacity was achieved by: soaking the seeds in GA3 solution irrespective of concentration; stratifying, irrespective of period; or soaking in 7.5 mg L-1 thiourea solution, values significantly varied from that of the control treatments. The sowing time was not relevant in terms of the percentage of germination or seedling development. Stratification at 5°C for 60 days produced the best quality indices for N. glauca seedlings but no significant differences were found in any of the morphological attributes tested as a result of the pre-germinative treatments. Conclusions: The pre-germinative treatments significantly improved the germination and seedlings growth of N. glauca. Cold stratification at 5°C for 60 days is recommended as it produced suitable seedlings for field establishment. Gibberellic acid and thiourea did not produce important effects on seedling growth. Our results suggest the presence of endogenous physiological dormancy of the N. glauca seeds. The results of this study provide important information on propagation and nursery techniques of N. glauca, which can be used in restoration programmes.

scholarly journals Germination of Japanese Stewartia Seeds: The Effects of Warm and Cold Stratification

1999 ◽  
Vol 17 (4) ◽  
pp. 197-202
Author(s):  
Daniel K. Struve ◽  
Brian A. Oleksak ◽  
Takayuki Kawahara ◽  
Ayako Kanazashi
Keyword(s):  
Seed Dormancy ◽  
Cold Stratification ◽  
Mother Tree ◽  
The Third ◽  
High Germination

Abstract Japanese Stewartia (Stewartia pseudocamellia (Maxim.)) is a species with outstanding landscape qualities, but is not widely available because reliable propagation protocols have not been developed, including procedures for overcoming seed dormancy. Three experiments were conducted to determine the warm and cold stratification requirements of Japanese Stewartia seeds. In the first experiment, seeds given a 3-day aerated water soak in 1 mM GA3, followed by 3 months warm moist stratification at 25C (77F) had greater germination 173 to 297 days after initiation of cold (7C, 45F) stratification than seeds given a 3-day aerated water soak and similar warm and cold stratification treatments. Final germination was 70%, but germination was not synchronous, it occurred over 172 days. In the second experiment, germination was low (less than 1%) for seeds given either 9 months cold moist stratification or 3 months warm moist stratification at 20C (68F) before 6 months cold moist stratification. Seeds given a 3-month warm moist stratification at an alternating 12 hr 20/12C (68/54F) cycles and 10 months cold moist stratification germinated from 30 to 93%, depending on mother tree. Germination was asynchronous, beginning after 150 days cold stratification and continuing for the next 165 days. In the third experiment, germination was not enhanced by a 3-day aerated water soak in either 1 mM GA3 or water, compared with seeds given no aerated water soak prior to cold moist stratification. Germination was greatest, 35%, for seeds given a 3-month warm moist stratification at 15C (59F) followed by at least 4 months cold moist stratification. However, germination was asynchronous. The results begin to identify the warm and cold stratification treatments that result in high germination.

scholarly journals Propagation of Two Native Shrubs, Rhamnus alnifolia and Rhamnus lanceolata

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 890A-890
Author(s):  
Jyotsna Sharma* ◽  
William R. Graves
Keyword(s):  
Seed Germination ◽  
Butyric Acid ◽  
Seed Treatment ◽  
Cold Stratification ◽  
Germination Success ◽  
Native Shrubs ◽  
Germination Value

Rhamnus alnifolia and Rhamnus lanceolata are shrubs of modest size with lustrous foliage. We evaluated seed germination of both species and propagated R. alnifolia by using softwood cuttings collected in early June. For R. alnifolia, cold stratification for up to 90 d resulted in 48% germination and a germination value of 1.9, whereas only 7% germination occurred among seeds stratified for 120 d. Seeds of R. alnifolia did not germinate if they were untreated or if scarified and stratified. Rhamnus lanceolata required 120 d of stratification to germinate, but percentages were low (≤ 5). Survival of germinants of both species was 90 to 100% regardless of prior seed treatment. Seedlings grew uniformly and had a mean leaf count of 11 and a mean height of 20 cm after 102 d. Application of 3000 and 8000 mg/L indole-3-butyric acid (IBA) in talc led to 85% rooting of R. alnifolia, whereas rooting was ≤ 15% after use of solutions with those IBA concentrations. While 75% of untreated cuttings rooted, fewer roots formed without IBA. More roots developed in 100% vermiculite than in 1 vermiculite: 1 perlite (by volume), which also diminished the number and apparent health of leaves on cuttings during the rooting period. We conclude that talc-based IBA and vermiculite should be used to root softwood cuttings of R. alnifolia, and that both species can be propagated from stratified seeds. Rhamnus lanceolata is more recalcitrant than is R. alnifolia and merits further study to optimize germination success.

scholarly journals Evidence of interpopulation variation in the germination of Eryngium maritimum L. (Apiaceae)

Plant Ecology ◽  
2021 ◽  
Author(s):  
I. Cortés-Fernández ◽  
M. D. Cerrato ◽  
A. Ribas-Serra ◽  
C. Cardona ◽  
C. González ◽  
...  
Keyword(s):  
Incubation Temperature ◽  
Potential Effect ◽  
Mean Annual Temperature ◽  
Cold Stratification ◽  
Mediterranean Populations ◽  
High Germination ◽  
Two Factors ◽  
Different Temperatures ◽  
Incubation Temperatures ◽  
Eryngium Maritimum

AbstractGermination is considered as one of the most crucial steps in a plant’s lifetime. The germination of Eryngium maritimum, a dune species located across all European coasts, has been extensively analysed in Northern populations, where it is considered a locally endangered species. However, less attention has been given to southern populations, where the knowledge about the germination of the species is very limited. The main objective of the present study was to analyse the effect of cold stratification in one Mediterranean and one Atlantic population of the species, as well as to compare the potential variation of seed dormancy among a latitudinal gradient in European populations based on current literature. Seeds collected from Mallorca (Mediterranean, Spain) and Asturias (Atlantic, Spain) were germinated at different temperatures and cold stratification periods ranging from 4 to 20 weeks. These results were merged with the results of previous studies to test the potential effect of latitude and climatic variables in germination. Although the optimal incubation temperature was 10 ºC, the highest final germination percentages (up to 96%) was obtained in both populations combining specific cold stratification periods (5 ºC) and constant incubation temperatures (15–20 ºC). Atlantic seeds needed longer cold stratification times to reach high germination percentages compared with Mediterranean seeds. Apart from the stratification response, significant differences in viability and in germination were observed between the Atlantic and the Mediterranean populations. Considering data from previous studies in the analysis, the results suggest that there is a potential effect of latitude in the ecological germination requirements, by which the higher the latitude, the longer the cold stratification period required to germinate, with a correlation with the mean annual temperature. These results suggests that two factors, modulation of dormancy relating to adaptative or maternal effects and viability, govern the germination of the species.

Bacca quo vadis: Regeneration niche differences among seven sympatric Vaccinim species on headlands of Newfoundland

2000 ◽  
Vol 10 (1) ◽  
pp. 89-97 ◽  
Author(s):  
Sam P. Vander Kloet ◽  
Nick M. Hill
Keyword(s):  
Single Species ◽  
Regeneration Niche ◽  
Niche Differences ◽  
Germination Success ◽  
Dispersal Unit ◽  
Species Groups ◽  
Regeneration Strategies ◽  
Quo Vadis ◽  
Natural Dispersal ◽  
Insight Into

AbstractOn headlands in Newfoundland, four of the seven sympatric Vaccinium species co-occur frequently at the quadrat level in tundra communities. We hypothesized that differentiation at the regeneration niche level was a prerequisite for the coexistence of these sympatric congeners. After a description and quantification of parameters affecting whole berry and seed dispersal and those affecting seed germination, differentiation at these two levels of the regeneration niches of the seven Vaccinia was investigated using numerical clustering techniques. Differentiation patterns were similar in both the germination and the dispersal dendrograms; three species were most dissimilar (viz. V. angustifolium, V. boreale and V. uliginosum), and the remaining four were separated into single species groups at the 62% and 75% similarity levels by the germination and dispersal dendrograms, respectively. Overall, patterns reflect divergence in dispersal mechanisms and germination abilities among the seven species, in support of the thesis that sympatric congeners have varied regeneration strategies. Differences in the germination success observed after testing natural dispersal units (e.g. seed from scat and seed within whole berries) points to the need to conduct germination trials in ecologically relevant ways. This approach reveals how divergent regeneration strategies are possible in species having similar, palatable baccate fruits (e.g. V. angustifolium and V. uliginosum) and highlights our lack of insight into regeneration strategies of the groups. The cranberry seeds, despite germination success gauged by results from standard germination protocols, exhibit no germination in trials conducted with the natural dispersal unit, the whole berry.

scholarly journals Cold Stratification and Pericarp Removal Improve Seed Germination of Ptelea trifoliata and Ptelea crenulata

HortScience ◽  
2020 ◽  
Vol 55 (4) ◽  
pp. 503-506
Author(s):  
Anna J. Talcott ◽  
William R. Graves
Keyword(s):  
Germination Percentage ◽  
Cold Stratification ◽  
Tetrazolium Chloride ◽  
Germination Success ◽  
Swallowtail Butterflies ◽  
Viable Seeds ◽  
Managed Landscapes ◽  
Germination Value ◽  
Improve Seed Germination ◽  
Peak Value

Two species of North American shrubs in the genus Ptelea (Rutaceae), commonly known as eastern and western hoptree or wafer ash, have unfulfilled potential to increase the diversity of managed landscapes and support populations of pollinators and swallowtail butterflies. The white flowers of Ptelea are highly fragrant, and pistillate flowers give rise to clusters of distinctive samaras. The insufficiency of information about improving germination of seeds of Ptelea trifoliata and lack of recommendations for Ptelea crenulata prompted us to investigate effects of pericarp removal and cold (4 °C) stratification periods of 0, 4, 8, and 16 weeks on the germination of seeds of these two species. Samaras were collected from multiple plants of both species in the midwestern United States (P. trifoliata) and California (P. crenulata). The germination percentage of viable seeds, calculated after tests of viability with tetrazolium chloride of seeds that did not germinate, increased with longer stratification periods, with 100% germination for P. crenulata and 91% germination for P. trifoliata after 16 weeks of stratification. The germination value, a measure of the speed and uniformity of germination, and peak value also increased with longer stratification in both species. Pericarp removal increased the germination percentage of both species and increased the peak and germination value of P. crenulata. Propagators seeking to grow these species of Ptelea from seed should remove the pericarp and cold-stratify seeds for 16 weeks to improve germination success.

Seeds of the threatened dry rainforest tree Cadellia pentastylis (Surianaceae) are non-dormant

2022 ◽  
pp. 1-5
Author(s):  
Nathan J. Emery ◽  
Justin C. Collette
Keyword(s):  
Heat Shock ◽  
Gibberellic Acid ◽  
Ex Situ ◽  
Physical Dormancy ◽  
Palisade Cell ◽  
Physiological Dormancy ◽  
Germination Success ◽  
Pre Treatment ◽  
Insect Predation ◽  
Smoke Water

Abstract Cadellia pentastylis (Surianaceae) is an Australian endemic threatened rainforest tree. Irregular flowering and fruiting events coupled with high rates of infertility and insect predation has meant that seed testing has not been possible for this species. Seeds were opportunistically collected from a wild population in early 2021, which allowed for the first germination tests to be conducted. In this study, the presence of physical dormancy was examined by performing an imbibition test using scarified and non-scarified seeds. We also investigated whether a 5-min heat shock treatment at temperatures ranging from 60 to 120°C improved germination success. The presence of physiological dormancy was also examined by recording germination success following a gibberellic acid or smoke-water pre-treatment. Both scarified and non-scarified seeds readily imbibed water over a 72-h period, and several seeds had germinated in both treatments after 48 h. Final germination proportion and t50 following a heat shock, gibberellic acid or smoke-water pre-treatment did not significantly differ from the controls. We conclude that C. pentastylis seeds are non-dormant. Although a palisade cell layer has been reported in the endocarp, our results suggest that this layer may not be sufficiently formed to restrict germination. We recommend that seeds are collected from populations following dispersal and propagated shortly after or stored as conservation collections in ex situ Seedbanks.

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