scholarly journals Plant origin determines seed mass, seed nutrients and germination behavior of a dominant grass species

2020 ◽  
Author(s):  
Andrea Veselá ◽  
Lien Duongová ◽  
Zuzana Münzbergová
Keyword(s):  
Vegetative Reproduction ◽  
Seed Mass ◽  
Seed Viability ◽  
Plant Performance ◽  
Grass Species ◽  
Nutrient Concentrations ◽  
Nitrogen And Phosphorus ◽  
Vegetative Traits ◽  
Germination Behaviour ◽  
Viable Seeds

AbstractAlthough number of studies exploring effects of climate change on plants is increasing, only few studies pay attention to germination. Understanding of germination behaviour is complicated by impact of climate on seed mass and possibly also seed nutrients, which play irreplaceable role in nourishing the sprout. The germination behaviour of species may also depend on trade-off between generative and vegetative reproduction.We studied Festuca rubra originating from localities situated along a natural climatic grid. Seeds of different origin were germinated in two temperature and two moisture regimes, simulating the extremes of the grid. To study relationship between generative and vegetative reproduction we used data on vegetative traits originating from the same study system.Seed mass and nutrient concentrations (nitrogen and phosphorus) were significantly affected by original climate, while carbohydrates not. Higher seed mass and warm temperature of origin caused higher and faster germination. Warm and dry condition during germination caused the lowest germination but the highest seed viability. Total germination and proportion of viable seeds negatively correlated with plant performance variables contributing to vegetative reproduction. Despite this, the patterns detected using datasets of germination and plant performance, did not provide fully comparable results.Simulated changes in climatic condition can modify seed mass and seed nutrients and these changes translate into changes in species germination behavior. After accounting for seed mass, both original and target conditions determine species germination indicating that both genetic differentiation as well as actual conditions drive the germination patterns. As the patterns detected at the level of seed germination do not fully match those detected for the vegetative traits, we urge that future studies should focus on multiple stages of plant life to understand species responses to future climates.

scholarly journals Survival of endophyte-infected ryegrass seed buried in soil

1999 ◽  
Vol 7 ◽  
pp. 151-156
Author(s):  
D.E. Hume ◽  
M.P. Rolston ◽  
D.B. Baird ◽  
W.J. Archie ◽  
M.R. Marsh
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Seed Viability ◽  
Seed Storage ◽  
Fungal Endophyte ◽  
Grass Species ◽  
Soil Conditions ◽  
Neotyphodium Lolii ◽  
Viable Seeds ◽  
One Year

Emergence of volunteer perennial ryegrass (Lolium perenne L.) from seed buried in soil may contribute to the ingress of ryegrass in newly sown pastures. To investigate this, ryegrass seed infected with fungal endophyte (Neotyphodium lolii) was buried in nylon bags under pasture at two depths and at two sites (Palmerston North, Lincoln) in early/mid-autumn 1998. Seed bags were removed from the soil at intervals over the course of one year to determine seed viability and presence of endophyte in seedlings. Viability of seed declined rapidly to be 10% 3 months after burial. Further decline in viability was less, so that 12 months after burial 4% of seeds were still viable. Endophyte viability also declined, from 58% infection of seedlings at the time of burial to 21% at 12 months. This was at a slower rate than the decline in seed viability and from what might have been predicted from seed storage experiments. Viability of seed buried at 10 cm was greater than that buried at 3 cm (e.g., means, 10% and 1% after 6 months, respectively). This has implications for cultivation practices before pasture establishment. Seed buried at Lincoln maintained higher viability than seed buried at Palmerston North (e.g., means, 6% and 4% after 6 months, respectively), which was associated with drier soil conditions at Lincoln. Survival of buried seed may therefore be of greater importance in summer-dry east coast regions, compared with moist west coast environments or in wet years. The significance of buried ryegrass seed will depend on the numbers involved, but after 12 months there were still viable seeds left in the soil and some of these were infected with endophyte. This is important for pastures sown with ryegrass that is free of endophyte or infected with a selected endophyte, and for slower establishing grass species such as tall fescue. Keywords: endophyte, endophyte survival, Lolium perenne, Neotyphodium lolii, perennial ryegrass, seed burial, seed survival

scholarly journals Nitrogen and Phosphorus Uptake Dynamics in Tropical Cerrado Woodland Streams

Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 1080 ◽  
Author(s):  
Nícolas Reinaldo Finkler ◽  
Flavia Tromboni ◽  
Iola Boëchat ◽  
Björn Gücker ◽  
Davi Gasparini Fernandes Cunha
Keyword(s):  
Nutrient Uptake ◽  
N Uptake ◽  
Pollution Abatement ◽  
Phosphorus Uptake ◽  
Soluble Reactive Phosphorus ◽  
Nitrogen Retention ◽  
Water Velocity ◽  
Nutrient Concentrations ◽  
Nitrogen And Phosphorus ◽  
Lotic Ecosystem

Pollution abatement through phosphorus and nitrogen retention is a key ecosystem service provided by streams. Human activities have been changing in-stream nutrient concentrations, thereby altering lotic ecosystem functioning, especially in developing countries. We estimated nutrient uptake metrics (ambient uptake length, areal uptake rate, and uptake velocity) for nitrate (NO3–N), ammonium (NH4–N), and soluble reactive phosphorus (SRP) in four tropical Cerrado headwater streams during 2017, through whole-stream nutrient addition experiments. According to multiple regression models, ambient SRP concentration was an important explanatory variable of nutrient uptake. Further, best models included ambient NO3–N and water velocity (for NO3–N uptake metrics), dissolved oxygen (DO) and canopy cover (for NH4–N); and DO, discharge, water velocity, and temperature (for SRP). The best kinetic models describing nutrient uptake were efficiency-loss (R2 from 0.47–0.88) and first-order models (R2 from 0.60–0.85). NO3–N, NH4–N, and SRP uptake in these streams seemed coupled as a result of complex interactions of biotic P limitation, abiotic P cycling processes, and the preferential uptake of NH4–N among N-forms. Global change effects on these tropical streams, such as temperature increase and nutrient enrichment due to urban and agricultural expansion, may have adverse and partially unpredictable impacts on whole-stream nutrient processing.

Frost hardiness and winter photosynthesis of Thujapiicata and Pseudotsugamenzlesll seedlings grown at three rates of nitrogen and phosphorus supply

1995 ◽  
Vol 25 (1) ◽  
pp. 18-28 ◽  
Author(s):  
B.J. Hawkins ◽  
M. Davradou ◽  
D. Pier ◽  
R. Shortt
Keyword(s):  
Net Photosynthesis ◽  
Douglas Fir ◽  
Frost Hardiness ◽  
Nutrient Concentrations ◽  
Nitrogen And Phosphorus ◽  
Red Cedar ◽  
Air Temperatures ◽  
Foliar Nutrient ◽  
One Year ◽  
P Supply

One-year-old seedlings of western red cedar (Thujapiicata Donn ex D.Don) and Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) were grown for one season in five nutrient treatments with nitrogen (N) supplied in solution at rates of 20, 100, or 250 mg•L−1 and phosphorus (P) supplied at rates of 4, 20, or 60 mg•L−1. Growth, onset of dormancy, frost hardiness on six dates, and foliar nutrient concentrations in autumn and spring were measured. Midwinter rates of net photosynthesis and transpiration were measured at air temperatures of 4, 7, and 11 °C in seedlings from all nutrient treatments. Recovery of net photosynthesis and transpiration in whole seedlings from the three N treatments was assessed at intervals for 28 days after the seedlings were frozen to −5, −15, and −25°C. Foliar N content differed significantly among nutrient treatments and was positively correlated with supply. Mitotic activity ceased earliest in plants with low N supply. Douglas-fir seedlings in the low-N treatment also ceased height growth earliest. These differences in growth had no significant correlation with frost hardiness. No consistent differences in frost hardiness among nutrient treatments were observed. Higher rates of N and P supply resulted in higher rates of winter net photosynthesis. Net photosynthesis was reduced dramatically by night frost, with greater damage occurring at lower temperatures. Net photosynthesis recovery occurred most quickly in seedlings with the midrate of N and P supply.

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.

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°C produce viable seeds. If cut and prostrated on insolated ground inflorescences can experience temperatures exceeding 50°C which may impair seed viability. We determined the effect of desiccation temperature (5, 15, 25, 35, 45 or 55°C) on viability of ripening seeds using inflorescences harvested on September 5, 2008 at Prague-Ruzyne (50°05'N, 14°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°C. Ripening seeds of maturing capitula only remained germinable if desiccation temperatures were ≤ 35°C (optimum 25°C) and were killed at 45 and 55°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.  

scholarly journals Differences in growth-economics of fast vs. slow growing grass species in response to temperature and nitrogen limitation individually, and in combination

BMC Ecology ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Claudia Colesie ◽  
Zsofia Reka Stangl ◽  
Vaughan Hurry
Keyword(s):  
Nutrient Availability ◽  
Nitrogen Availability ◽  
Global Environmental Change ◽  
Performance Outcomes ◽  
Plant Performance ◽  
Grass Species ◽  
Growth Responses ◽  
Fast Growing ◽  
Environment Temperature ◽  
Slow Growing

Abstract Background Fast growing invasive alien species are highly efficient with little investment in their tissues. They often outcompete slower growing species with severe consequences for diversity and community composition. The plant economics trait-based approach provides a theoretical framework, allowing the classification of plants with different performance characteristics. However, in multifaceted background, this approach needs testing. The evaluation and prediction of plant performance outcomes in ecologically relevant settings is among the most pressing topics to understand and predict ecosystem functioning, especially in a quickly changing environment. Temperature and nutrient availability are major components of the global environmental change and this study examines the response of growth economic traits, photosynthesis and respiration to such changes for an invasive fast-growing (Bromus hordaceus) and a slow-growing perennial (Bromus erectus) grass species. Results The fully controlled growth chamber experiment simulated temperature—and changes in nitrogen availability individually and in combination. We therefore provide maximum control and monitoring of growth responses allowing general growth trait response patterns to be tested. Under optimal nitrogen availability the slow growing B. erectus was better able to handle the lower temperatures (7 °C) whilst both species had problems at higher temperatures (30 °C). Stresses produced by a combination of heat and nutrient availability were identified to be less limiting for the slow growing species but the combination of chilling with low nutrient availability was most detrimental to both species. Conclusions For the fast-growing invader B. hordeaceus a reduction of nitrogen availability in combination with a temperature increase, leads to limited growth performance in comparison to the slow-growing perennial species B.erectus and this may explain why nutrient-rich habitats often experience more invasion than resource-poor habitats.

Effect of Ensiling and Rumen Digestion by Cattle on Weed Seed Viability

Weed Science ◽  
1991 ◽  
Vol 39 (1) ◽  
pp. 104-108 ◽  
Author(s):  
Robert E. Blackshaw ◽  
Lyle M. Rode
Keyword(s):  
Time Course ◽  
Seed Viability ◽  
Grass Species ◽  
Lag Phase ◽  
Rapid Decline ◽  
Weed Species ◽  
Embryo Viability ◽  
Seed Survival ◽  
Gradual Process ◽  
Broadleaf Species

Studies were conducted to determine the effect of ensiling and/or rumen digestion by cattle on the germination and viability of several common weed species. Seed survival of grass species subjected to ensiling and/or rumen digestion tended to be less than that of broadleaf species. Downy brome, foxtail barley, and barnyardgrass were nonviable after either ensiling for 8 weeks or rumen digestion for 24 h. Some green foxtail (17%) and wild oats (0 to 88%) seeds survived digestion in the rumen but were killed by the ensiling process. Varying percentages of seeds of kochia, redroot pigweed, common lambsquarters, wild buckwheat, round-leaved mallow, and field pennycress remained viable after ensiling (3 to 30%), rumen digestion (15 to 98%), and ensiling plus rumen digestion (2 to 19%). A time course study of rumen digestion indicated that loss of seed viability often was not a gradual process. With some species, there was an initial lag phase while degradation of the protective seed coat likely occurred, followed by a rapid decline in embryo viability. The diet fed to livestock appeared to affect viability losses caused by rumen digestion. Estimates of seed survival with varying rates of passage through the rumen due to differing ratios of grain to forage in the diet are presented.

scholarly journals Chemical Element Concentrations of Cycad Leaves: Do We Know Enough?

Horticulturae ◽  
2020 ◽  
Vol 6 (4) ◽  
pp. 85 ◽  
Author(s):  
Benjamin E. Deloso ◽  
Murukesan V. Krishnapillai ◽  
Ulysses F. Ferreras ◽  
Anders J. Lindström ◽  
Michael Calonje ◽  
...  
Keyword(s):  
Root Zone ◽  
Chemical Elements ◽  
Incident Light ◽  
Leaf Age ◽  
Influential Factors ◽  
Nutrient Concentrations ◽  
Future Research ◽  
Nitrogen And Phosphorus ◽  
Element Concentrations

The literature containing which chemical elements are found in cycad leaves was reviewed to determine the range in values of concentrations reported for essential and beneficial elements. We found 46 of the 358 described cycad species had at least one element reported to date. The only genus that was missing from the data was Microcycas. Many of the species reports contained concentrations of one to several macronutrients and no other elements. The cycad leaves contained greater nitrogen and phosphorus concentrations than the reported means for plants throughout the world. Magnesium was identified as the macronutrient that has been least studied. Only 14 of the species were represented by data from in situ locations, with most of the data obtained from managed plants in botanic gardens. Leaf element concentrations were influenced by biotic factors such as plant size, leaf age, and leaflet position on the rachis. Leaf element concentrations were influenced by environmental factors such as incident light and soil nutrient concentrations within the root zone. These influential factors were missing from many of the reports, rendering the results ambiguous and comparisons among studies difficult. Future research should include the addition of more taxa, more in situ locations, the influence of season, and the influence of herbivory to more fully understand leaf nutrition for cycads.

scholarly journals Flood water quality and marine sediment and nutrient loads from the Tully and Murray catchments in north Queensland, Australia

2009 ◽  
Vol 60 (11) ◽  
pp. 1123 ◽  
Author(s):  
Jim Wallace ◽  
Lachlan Stewart ◽  
Aaron Hawdon ◽  
Rex Keen ◽  
Fazlul Karim ◽  
...  
Keyword(s):  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Inorganic Nitrogen ◽  
Nutrient Concentrations ◽  
Large Contribution ◽  
Nutrient Loads ◽  
Nitrogen And Phosphorus ◽  
Annual Average ◽  
Nitrogen Loads ◽  
Flood Flows

Current estimates of sediment and nutrient loads from the Tully–Murray floodplain to the Great Barrier Reef lagoon are updated by taking explicit account of flood events. New estimates of flood discharge that include over-bank flows are combined with direct measurements of sediment and nutrient concentrations in flood waters to calculate the loads of sediment and nutrient delivered to the ocean during 13 floods that occurred between 2006 and 2008. Although absolute concentrations of sediment and nutrient were quite low, the large volume of water discharged during floods means that they make a large contribution (30–50%) to the marine load. By not accounting for flood flows correctly, previous estimates of the annual average discharge are 15% too low and annual loads of nitrogen and phosphorus are 47% and 32% too low respectively. However, because sediments may be source-limited, accounting for flood flows simply dilutes their concentration and the resulting annual average load is similar to that previously estimated. Flood waters also carry more dissolved organic nitrogen than dissolved inorganic nitrogen and this is the opposite of their concentrations in river water. Consequently, dissolved organic nitrogen loads to the ocean may be around twice those previously estimated from riverine data.

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