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 Primary seed dispersal by a sigmodontine rodent assemblage in a Peruvian montane forest

2016 ◽  
Vol 32 (2) ◽  
pp. 125-134 ◽  
Author(s):  
Catherine Teresa Sahley ◽  
Klauss Cervantes ◽  
Edith Salas ◽  
Diego Paredes ◽  
Victor Pacheco ◽  
...  
Keyword(s):  
Seed Dispersal ◽  
Seed Viability ◽  
High Elevation ◽  
Rodent Species ◽  
Faecal Samples ◽  
Plant Families ◽  
Viable Seeds ◽  
Montane Tropical Forest ◽  
Rodent Abundance ◽  
Disperser Effectiveness

Abstract:We examined quantity and quality components of primary seed dispersal for an assemblage of sigmodontine rodents in a high-elevation montane tropical forest in Peru. We collected faecal samples from 134 individuals belonging to seven rodent species from the subfamily Sigmodontinae (Cricetidae) over a 2-y period. We conducted seed viability tests for seeds found in faecal samples. We identified seeds from eight plant families (Bromeliaceae, Annonaceae, Brassicaceae, Ericaceae, Melastomatacae, Myrtaceae, Rosaceae, Solanaceae), nine genera and 13 morphospecies. The most abundant seeds belonged toGaultheriasp. 1 (46% of total) andMiconiasp. 1 (31% of total), while the most viable seeds belonged toGreigiasp. (84% viability) andGuatteriasp. (80% viability). We utilized relative rodent abundance, seed species diversity, seed abundance and seed viability per rodent species to calculate an index of rodent disperser effectiveness, and found thatThomasomys kalinowskiiwas the most effective disperser, followed byAkodon torques,Calomys sorellus,Thomasomys oreas,Oligoryzomys andinusandMicroryzomys minutus. Plant genera dispersed by sigmodontine rodents overlapped more with bird- and terrestrial-mammal-dispersed plants than with bat-dispersed plants. Future neotropical seed dispersal studies should consider small rodents as potential seed-dispersers, especially in tropical habitats where small-seeded, berry-forming shrubs and trees are present.

scholarly journals Phenology and seed germination behaviours of some wetland macrophytes at Biratnagar, Nepal

2016 ◽  
Vol 6 (1) ◽  
pp. 19-23
Author(s):  
Bhabindra Niroula ◽  
Praju Panta
Keyword(s):  
Seed Germination ◽  
Filter Paper ◽  
Seed Viability ◽  
Seed Morphology ◽  
Wetland Plants ◽  
Seed Maturation ◽  
Vegetative Phase ◽  
Percent Germination ◽  
Viable Seeds ◽  
Number Of Seeds

Phenology, seed morphology, seed viability and germination behabiour of some wetland plants in control at moist filter paper in petridishes was carried out in wetland plants-Aeschynemone asper L. (Fabaceae); Eragrostis unioloides (Retz.) Nees exsteudel (Poaceae); Hygrophila auriculata (K. Schum) Heine (Acanthaceae); Pesicaria barbatum (L.) Hara (Polygonaceae); and Rumex dentatus L. (Polygonaceae) were studied at Biratnagar. Number of seeds per gram ranged between161-12722. Viable seeds of A. asper (98%) and P. barbatum (55%) had no germination but E. unioloides had cent percent germination; H. auriculata, and Rumex dentatus showed 96% germination. A.asper and E. unioloides germinated in early rainy; spent vegetative phase up to August- September; and completed flowering, fruiting and seed maturation before winter.

scholarly journals Seed dispersal of Solanum thomasiifolium Sendtner (Solanaceae) in the Linhares Forest, Espírito Santo state, Brazil

2009 ◽  
Vol 23 (4) ◽  
pp. 1171-1179 ◽  
Author(s):  
João Vasconcellos-Neto ◽  
Lidiamar Barbosa de Albuquerque ◽  
Wesley Rodrigues Silva
Keyword(s):  
Seed Dispersal ◽  
Control Bird ◽  
Brazilian Coast ◽  
Espírito Santo ◽  
Bird Droppings ◽  
Fruit Productivity ◽  
Habitat Colonization ◽  
Viable Seeds ◽  
Espirito Santo ◽  
And Control

The aim of this study was to analyse seed dispersal and establishment of Solanum thomasiifolium in an area of "nativo" vegetation in Espirito Santo state on the southeastern Brazilian coast. Ten species of birds, the crab-eating fox (Cerdocyon thous), and one species of lizard (Tropidurus torquatus) fed on S. thomasiifolium fruits and dispersed viable seeds in their faeces. The proportional contribution of each of these groups to seed dispersal was 77% (birds), 19% (crab-eating fox) and 4% (lizards). Ants also contributed to seed dispersal. More seeds were deposited in vegetation islands than in the surrounding open areas. Germination rates of seeds collected directly from fruit (control), bird droppings, the faeces of crab-eating foxes and lizards were, respectively, 64, 64, 53, and 80 %. Differences among these rates were all significant, except between birds and control. Lizards were important as seed carriers between nearby islands and they expelled a higher proportion of viable seeds. Birds and the crab-eating foxes did not enhance seed germination, but promoted seed dispersal over a wider area. Plant architecture, fruit productivity, fruit characteristics and the diversity of frugivores are important for the success of S. thomasiifolium in habitat colonization.

Quantitative reduction of triphenyl tetrazolium chloride as a measure of viability in cereal seeds

1972 ◽  
Vol 12 (58) ◽  
pp. 517 ◽  
Author(s):  
RL Harty ◽  
LG Paleg ◽  
D Aspinall
Keyword(s):  
Sample Size ◽  
Standard Procedure ◽  
Seed Viability ◽  
Close Correlation ◽  
Triphenyl Tetrazolium Chloride ◽  
Tetrazolium Chloride ◽  
Enzyme Systems ◽  
Dehydrogenase Enzyme ◽  
Viable Seeds ◽  
Extracting Solvent

The reduction of 2,3,5-triphenyl tetrazolium chloride (TTC) to a coloured formazan derivative by dehydrogenase enzyme systems in viable seeds has been examined. TTC reduction occurs in dry but not wetmilled tissue and the coloured product could be extracted by any of several organic solvents. This formazan product was estimated spectrophotometrically at 480 nm. The influence of fineness of grinding the tissue, TTC concentration, period of treatment, sample size, vacuum infiltration of the milled tissue with TTC and of extracting solvent were examined and a standard procedure is suggested. Using this procedure, a close correlation between seed viability and TTC reduction was demonstrated. The advantages of this method over the widely used topographical method for estimating seed viability with TTC are discussed.

Selection and Processing of Serotinous Pitch Pine Cones

1995 ◽  
Vol 12 (2) ◽  
pp. 64-68 ◽  
Author(s):  
Robert A. Fimbel ◽  
Cheryl C. Fimbel ◽  
John E. Kuser
Keyword(s):  
Late Summer ◽  
Oak Forests ◽  
Phenotypic Characteristics ◽  
Convection Oven ◽  
Pitch Pine ◽  
Application Techniques ◽  
Heat Application ◽  
Viable Seeds ◽  
Pine Cones ◽  
Germinating Seeds

Abstract We examined phenotypic characteristics of serotinous pitch pine cones from the dwarfed pine-oak forests of the New Jersey Pine Barren Plains, and three heat-application techniques to release their seeds, to evaluate the influence of these factors on seed germination and seedling development. One- and two-year-old mature cones averaged twice the number of germinating seeds/cone as green cones collected in late summer, and larger cones yielded higher quantities of viable seeds compared to smaller ones. Treating serotinous cones in boiling water or a convection oven yielded higher germination rates than using a microwave oven, especially with green cones. Thirty-two months following germination, cone characteristics and opening techniques did not predict seedling performance in the field. Parent tree influenced seedling height. We present recommendations to maximize the number of viable propagules collected during the selection and processing of serotinous, dwarfed pitch pine cones. North. J. Appl. For. 12(2):64-58.

scholarly journals Electrical impedance spectroscopy in relation to seed viability and moisture content in snap bean (Phaseolus vulgaris L.)

2002 ◽  
Vol 12 (1) ◽  
pp. 17-29 ◽  
Author(s):  
T. Repo ◽  
D.H. Paine ◽  
A.G. Taylor
Keyword(s):  
Phaseolus Vulgaris ◽  
Impedance Spectroscopy ◽  
Moisture Content ◽  
Electrical Impedance ◽  
Seed Viability ◽  
Impedance Spectrum ◽  
Electrical Circuit ◽  
Electrical Impedance Spectroscopy ◽  
Snap Bean ◽  
Viable Seeds

A method, electrical impedance spectroscopy (EIS), is introduced to study seed viability non-destructively. Snap bean (Phaseolus vulgaris L.) seeds were studied by EIS to determine the most sensitive EIS parameter(s) and the optimal range of moisture content (MC) for separation of viable and non-viable seeds. Hydrated seeds exhibited two impedance arcs in the complex plane at the frequency range from 60 Hz to 8 MHz, and impedance spectra of viable and non-viable seeds differed. The hydrated seeds were best-modelled by an equivalent electrical circuit with two distributed circuit elements in series with a resistor (Voigt model). Moisture content and seed viability had strong effects on the EIS parameters. The most sensitive EIS parameters for detecting the differences between viable and non-viable seeds were the capacitance log(C2), the resistance R2, the resistance ratio R2/R1 and the apex ratio, which all represent specific features of the impedance spectrum. The highest differentiation in the EIS parameters between the viable and non-viable seeds occurred in partially imbibed seeds between MC of 40 and 45% (fresh weight basis).

Dispersal and viability of seeds from cones in tops of harvested loblolly pines

2001 ◽  
Vol 31 (2) ◽  
pp. 357-362 ◽  
Author(s):  
Michael G Shelton ◽  
Michael D Cain
Keyword(s):  
Seed Maturation ◽  
Potential Contribution ◽  
Seed Supply ◽  
Seed Cone ◽  
Standing Trees ◽  
Loblolly Pines ◽  
Closed Canopy ◽  
Viable Seeds ◽  
Pinus Taeda L ◽  
Dispersal Period

Seed supply is one of the most important determinants of successful natural regeneration. We conducted a study to determine the potential contribution of cones in the tops of harvested loblolly pines (Pinus taeda L.) to the stand's seed supply if trees were felled after seed maturation but before dispersal. Closed cones, collected in October 1996, were stored in wire cages with periodic removals over 2 years to determine the number and viability of extracted seeds. Storage sites were an opening in a seed-tree stand and a closed-canopy pine-hardwood stand in southeastern Arkansas. Of the initial 83 viable seeds/cone, 73% had dispersed in the opening and 63% in the closed stand by March 1997, which is considered the end of the normal dispersal period from standing trees. By October 1997, only 1 viable seed/cone remained in the opening and 5 viable seeds/cone in the closed stand, indicating rather complete dispersal or mortality of seeds by the first summer after harvest. Results indicate that cones in tops of trees cut during the 2-month period after seed maturation and before substantial dispersal can make an important contribution to the stand's seed supply, especially in reproduction cutting methods where most of the trees are harvested.

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 Enhancing the Viability of Rosella Seeds (Hibiscus sabdariffa L.) through Tetrazolium and Paper Media Test

2019 ◽  
Vol 4 (1) ◽  
pp. 23-30
Author(s):  
Taufiq Hidayat RS ◽  
Mayasari Yamin
Keyword(s):  
Seed Viability ◽  
Dry Weight ◽  
Tetrazolium Salt ◽  
Hibiscus Sabdariffa ◽  
Germination Capacity ◽  
Randomized Design ◽  
Vigor Index ◽  
Normal Seedling ◽  
Best Parameter ◽  
Viable Seeds

This study was aimed to determine the viability rate of rosella seed, to obtain the best result of seed testing for enhancing rosella seed viability, to find the best seed invigoration method for enhancing rosella seed viability, to obtain staining pattern through tetrazolium test of rosella seed, and to determine viability and vigor of rosella seed to be further used as estimation indicator for rosella plant growth in the field. The study was conducted in the Seed Laboratory, Indonesian Sweetener and Fiber Crops Research Institute (ISFCRI), Malang, East Java during July - August 2018. The material used included accessions of rosella seed (Hibiscus sabdariffa L.) ACC. 1148 from the year 2015 and collection of ISFCRI, 100 ml of Tetrazolium solution (40 ml KH2PO4, 60 ml Na2HPO4 and 1 gr of Tetrazolium powder). This research applied Completely Randomized Design (CRD) consisted of seed treatments of control (no immersion/0 hour), immersion for 5 hours, immersion for 10 hours, and scarification, each with 4 replications. Result of this study showed that the use of tetrazolium salt was found to be better in enhancing the viability of rosella seeds. Viable seeds was found to have bright red embryonic axis and bright red cotyledon. Testing using paper media on several seed invigoration treatments resulted in significantly different effect on parameters of vigor index, germination capacity, and dry weight of normal seedling. The best parameter of germination capacity and dry weight of normal seedling was obtained by treatment immersed in water at temperature of 27°C for 10 hours

scholarly journals Self-pollination of the orchid Cycnoches haagii from Brazilian Cerrado results in albino phenotype seedlings

2022 ◽  
Vol 28 (1) ◽  
pp. 85-91
Author(s):  
Vespasiano Borges de Paiva Neto ◽  
Mateus de Aguiar Torrezan ◽  
Manoela Aparecida Vieira da Silva ◽  
Daly Roxana Castro Padilha ◽  
Jerônimo Constantino Borel ◽  
...  
Keyword(s):  
Seed Viability ◽  
Germination Percentage ◽  
Brazilian Cerrado ◽  
Conservation Programs ◽  
Pigment Analysis ◽  
High Germination ◽  
Half Strength ◽  
Albino Phenotype ◽  
Viable Seeds

Abstract Cycnoches haagii Barb. Rodr. is an epiphytic orchid very targeted by collectors, but no reference was found in the literature about its reproductive biology. Thus, the purpose of this study was to obtain initial information regarding pollination types and its influence on seed viability of this native orchid of the Brazilian Cerrado, in order to enable future propagation and preservation programs. Pollination among flowers of the same plant (geitonogamy) or different plants (xenogamy) were carried out. Seeds extracted from the capsules were sown in B&G medium, with full and half strength. Seeds from geitonogamic resulted in 25% of albino protocorms and consequently in albino seedlings. This phenomenon did not occur in seedlings derived from xenogamic pollination. Pigment analysis showed that even the albino seedlings presented chlorophylls and carotenoids, however, in significantly minor concentrations, 16% and 37% respectively, in relation to green seedlings. Geitonogamic and xenogamic pollinations resulted in C. haagii viable seeds with high germination percentage (90%) under in vitro conditions. The germination of seeds from xenogamic pollination resulted in chlorophyll or normal seedlings only, and can be recommended at conservation programs. On the other hand, although geitonogamic pollination should be avoided at conservation programs of this orchid species as it leads to albino seedlings, it showed a very interesting system to obtain seedlings with this phenotype, an interesting plant material to future investigation.

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