Propagation of yellow bells (Geleznowia verrucosa Turcz., Rutaceae) from seed

1991 ◽  
Vol 42 (5) ◽  
pp. 901 ◽  
Author(s):  
BH Paynter ◽  
KW Dixon
Keyword(s):  
Seed Dormancy ◽  
Tap Water ◽  
Germination Percentage ◽  
Percentage Germination ◽  
Untreated Seed ◽  
Factors Influencing ◽  
Germination Temperature ◽  
Commercially Important

Geleznowia verrucosa Turcz. (Rutaceae) is a commercially important, bush-picked wildflower that has no known commercial means of propagation. This study examined factors influencing seed dormancy and likely to restrict germination of the species. Germination of entire, untreated seed was low (less than 2%), but removal of a small portion of the testa at or near the radicle end of the seed improved germination. This response was affected by the temperature under which the seed germinated, but was unaffected by exposure of the seed to light while germinating. The percentage germination of nicked seeds 52 days after sowing increased from 8% to 16-19% by increasing the temperature from 15/10�C to 20/15�C; 55-60% of nicked seed germinated when the germination temperature was increased to 23/15�C. The germination of nicked seed was reduced by leaching in running tap water. Following 1 week of leaching the germination percentage of nicked seed at day 52 in the glasshouse was reduced from 16% to 9%, with a further decrease to 5% after 2 weeks of leaching. There was also no stimulatory effect on the germination of entire seeds by stratifying the seed at 5�C after periods of solarisation. It is concluded that dormancy of fresh seeds of G. verrucosa is caused, in part, by the mechanical restriction of the testa on embryo growth and elongation.

Polyploid Distribution and Seed Dormancy in Relation to Provenance Rainfall in the Digitaria milanjiana Complex

1988 ◽  
Vol 36 (6) ◽  
pp. 693 ◽  
Author(s):  
JB Hacker
Keyword(s):  
Seed Dormancy ◽  
Chromosome Numbers ◽  
Low Temperatures ◽  
Arid Regions ◽  
Germination Percentage ◽  
Genetic Adaptation ◽  
Percentage Germination ◽  
High Rainfall ◽  
Ungerminated Seed ◽  
Over Time

Chromosome numbers were counted in 72 accessions in the Digitaria milanjiana complex and 2 of D. macroblephara from contrasting climates in Africa; 18 were diploids, 38 tetraploids, and 18 hexaploids. Higher polyploids were mostly from lower rainfall provenances. Diploids were mostly accessions which had been attributed to other species in pre-1982 classifications but which are now considered to be synonyms of D. milanjiana. Some 29 accessions, including diploids, tetraploids and hexaploids from low-rainfall and high-rainfall provenances at equatorial or near-tropical latitudes were grown and seed was harvested on 2 occasions (Jan. and Mar. 1987). Seed was treated at alternating temp. of 30/25°C or constant 60°C for 0, 2, 6, 10 or 16 weeks and then germinated. Percentage germination increased over time for all accessions, from 1% at harvest to 26% at 16 weeks. Germination was markedly lower in accessions from low-rainfall (14%) than high-rainfall (33% at 16 weeks) provenances. Similarly, percentage germination was lower in hexaploids (16%) than tetraploids (26%) and lower in tetraploids than diploids (38% at 16 weeks). High temp. treatment increased germination percentage but the effect was only marked in accessions with comparatively high levels of germination at low temperatures. Percentage dormancy (estimations based on live but ungerminated seed after germination treatment following 16 weeks at 60°C) was significantly and negatively correlated with rainfall of provenance. It was concluded that seed dormancy in D. milanjiana is related both to polyploidy and rainfall of provenance and that genetic adaptation to arid regions has been associated with polyploidisation and increasing dormancy.

Effect of Tree Spacing, Cone Storage, and Prechilling on Germination of Picea glauca Seed

1990 ◽  
Vol 66 (4) ◽  
pp. 388-392 ◽  
Author(s):  
G. E. Caron ◽  
B. S. P. Wang ◽  
H. O. Schooley
Keyword(s):  
Seed Dormancy ◽  
Seed Yield ◽  
Picea Glauca ◽  
Seed Weight ◽  
Germination Rate ◽  
Germination Percentage ◽  
Seed Maturation ◽  
Percentage Germination ◽  
Seed Extraction ◽  
Production Area

Cones were collected in 1984 at the time of natural seed dissemination from 18 open-pollinated, 30-year-o!d white spruce (Picea glauca(Moench) Voss) trees at 1.2, 2.4, and 4.9 m spacings in a demonstration seed production area at Petawawa National Forestry Institute. Cones were stored in a well-ventilated building for 2 to 6 weeks before seed extraction.Cones length, full-seed-yield per cone, and full-seed weight were greatest for cones collected from trees at the 1.2 m spacing. When cones were stored for 2 weeks, non-prechilled and prechilled seeds averaged 32.0 ± 1.0% [Formula: see text] and 62.3 ± 1.0% germination, respectively. When cones were stored for 6 weeks, non-prechilled and prechilled seeds averaged 61.3 ± 1.2% and 94.7 ± 0.5% germination, respectively. The higher germination percentage, germination rate, and lower tree to tree variation for prechilled seeds from cones stored for 6 weeks indicate that seed maturation was promoted by post-harvest cone storage prior to seed extraction. Average seed dormancy remained about the same from 2 to 6 weeks of storage; however, seeds from some trees became more dormant with the storage whereas those from others became less dormant. Relationship between seed weight and germination was weak. Key words: Cone storage, seed prechilling, germination percentage, germination rate, seed maturation, seed dormancy, seed weight, seed sorting.

Morphophysiological dormancy and germination ecology in diaspores of the subtropical palm Phoenix canariensis Chabaud

Botany ◽  
2021 ◽  
Author(s):  
Lanlan He ◽  
Ganesh K. Jaganathan ◽  
Baolin Liu
Keyword(s):  
Seed Dormancy ◽  
Seedling Emergence ◽  
Primary Root ◽  
Germination Percentage ◽  
Early Summer ◽  
Germination Ecology ◽  
Phoenix Canariensis ◽  
Morphophysiological Dormancy ◽  
Cotyledonary Petiole ◽  
Seed Dormancy And Germination

The timing of germination is a crucial event in a plant’s life cycle. Seed dormancy and germination mechanisms are important factors regulating seedling emergence. Since detailed experimental evidence for germination pattern of Phoenix canariensis colonizing sub-tropical climate is scarce, we investigated seed dormancy and germination ecology of P. canariensis. We found that the embryo is underdeveloped at the time of dispersal and doubles in size before the cotyledonary petiole (CP) protrudes through the operculum. The primary root and plumule emerge from the elongated CP outside the seed. In light/dark at 30/25°C, the CP emerged from 8% of the diaspores within 30 days and from 76% within 14 weeks. Thus, 8% of the diaspores have MD and the others MPD. Removal of the pericarp and operculum resulted in 100% germination within 5 days in light/dark at 30/25°C. Cold and warm stratification as well as treatment with GA3 significantly increased the germination speed, but the final germination percentage was not significantly increased. Seed germination was synchronized in early summer when seed dormancy was released by cold stratification in the soil over winter. A remote-tubular germination type and intricate root system provide an ecological advantage to the seedling establishment.

scholarly journals SUPERAÇÃO DA DORMÊNCIA EM SEMENTES DE Plathymenia reticulata Benth.

Nativa ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 317
Author(s):  
Cássio Do Prado Borges ◽  
Cheila Deisy Ferreira ◽  
Daniela Pereira Dias
Keyword(s):  
Electrical Conductivity ◽  
Germination Percentage ◽  
Lateral Side ◽  
Detergent Solution ◽  
Sodium Hypochlorite Solution ◽  
Percentage Germination ◽  
Dormancy Breaking ◽  
Germination Speed ◽  
Mean Germination Time ◽  
T1 And T2

Este trabalho objetivou avaliar a germinação e vigor de sementes de Plathymenia reticulata Benth. submetidas a diferentes tratamentos para superação de dormência. Os tratamentos testados foram: controle - sementes intactas (T0), escarificação mecânica com lixa d’água nº 60 (T1), desponte na região lateral do tegumento (T2), imersão em água fervente por 10 min (T3), em hipoclorito de sódio por 15 min (T4) e em solução com detergente por 15 min (T5). Foram determinados: peso de mil sementes, grau de umidade, porcentagem de germinação, índice de velocidade de germinação (IVG), tempo médio de germinação (TMG), curva de embebição, teste da condutividade elétrica e comprimento da radícula. A porcentagem de germinação das sementes submetidas ao T1 e T2 foi estatisticamente igual (respectivamente, 90 e 88%) e superiores aos outros tratamentos testados (12%). As sementes expostas aos T1 e T2 apesentaram porcentagem de absorção de água superiores e em menor tempo, assim como maiores IVG e menores TMG, comparadas aos demais tratamentos. O comprimento das radículas não variou entre os tratamentos testados. A condutividade elétrica da solução com as sementes do T0 foi superior aos outros tratamentos testados. Sementes de P. reticulata expostas ao T1 e T2 apresentam maior germinação e vigor.Palavras-chave: germinação, índice de velocidade de germinação, teste de condutividade elétrica, vigor, vinhático. DORMANCY BREAKING OF Plathymenia reticulata Benth. SEEDS ABSTRACT:This study aimed to evaluate the germination and vigor of Plathymenia reticulata Benth. seeds submitted to different dormancy breaking treatments. Testing treatments were: control - intact seeds (T0); mechanical scarification with sandpaper n. 60 (T1), coating cutting in the lateral side of tegument (T2), immersion in boiling water during 10 min (T3), in sodium hypochlorite solution during 15 min (T4), and in detergent solution during 15 min (T5). Moisture content, 1000-seed weight, germination percentage, germination speed index (GSI), mean germination time (MGT), imbibition curve, electrical conductivity test, and radicle length were determined. Germination percentage to T1 and T2 were statistically equal (90 and 88 %, respectively) and higher than others treatments tested (12%). Seeds exposed to T1 and T2 also presented higher and faster water absorption percentage, when compared to the others treatments, as well as higher GSI, and lower MGT. The rootlets length did not vary among treatments tested. Electrical conductivity of intact seeds was higher than others treatments. P. reticulata seeds expose to T1 e T2 had highest germination percentage and vigor.Keywords: germination, germination speed index, electrical conductivity test, vigor, vinhático.

Effect of heavy metal stress on emerging plants community constructions in wetland

2010 ◽  
Vol 62 (10) ◽  
pp. 2459-2466 ◽  
Author(s):  
Han Peng ◽  
Wu Geng ◽  
Wu Yong-quan ◽  
Li Mao-teng ◽  
Xiang Jun ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Seed Germination ◽  
Seedling Growth ◽  
Heavy Metal Stress ◽  
Germination Percentage ◽  
Percentage Germination ◽  
Wetland Ecosystem ◽  
Ecological Thresholds ◽  
Hongze Lake ◽  
Seedling Length

In this paper, we report the effects of heavy metals (HMs) (cadmium and mercury) on seed germination and seedling growth of Phragmites australis and Triarrhena sacchariflora, which are the two main typical emerging plants in Hongze Lake wetland. The results showed that there was a reduction in germination percentage, germination index and seedling length as HM concentration in the growing media increased for both treatments. The effect of HMs toxicity on seed germination and seedling growth of T. sacchariflora was more obvious than of P. australis. At the stage of seed germination, P. australis and T. sacchariflora were sensitive to Hg2 +  and Cd2 + , respectively, and Hg2 +  was more toxic than Cd2 +  at the stage of seedling growth. The effect of HMs toxicity is not invariable during plant growth. Compared to the stage of seedling growth, P. australis and T. sacchariflora are more susceptible to HMs at the stage of seed germination. In addition, we calculated the ecological thresholds of P. australis to Cd and Hg are 19.32 and 1.08 mg kg−1, and that of T. sacchariflora to Cd is 4.62 mg kg−1 based on the lab simulation. The results also indicated that the species of P. australis is more tolerant than T. sacchariflora to the HMs and is a better candidate for restoration in Hongze Lake wetland ecosystem.

scholarly journals Sexual and Vegetative Propagation of Hypericum empetrifolium Willd. subsp. empetrifolium

2018 ◽  
Vol 47 (2) ◽  
pp. 282-287
Author(s):  
Anastasia AKOUMIANAKI-IOANNIDOU ◽  
Ekaterini GERASIMIDOU ◽  
Alexandra SALTA ◽  
Ioannis ROUSSIS ◽  
Dimitrios BILALIS
Keyword(s):  
Significant Interaction ◽  
Incubation Temperature ◽  
Tap Water ◽  
Hormone Treatment ◽  
Germination Percentage ◽  
Stem Cuttings ◽  
Treatment Control ◽  
Asexual Propagation ◽  
Different Types ◽  
Pharmaceutical Properties

Hypericum empetrifolium Willd. subsp. empetrifolium is an evergreen small shrub with small elongated decorative leaves and small yellow flowers in inflorescences, characterized for several pharmaceutical properties. In the present study, a first approach on the sexual and asexual propagation of this species was performed. Seeds, subjected to different types of pre-treatments [soaked in tap water; 50, 100 or 150 mg L-1 GA3 for 30 min and no treatment (control)], cultured for germination in petri dishes at 5, 10, 15, 20, 25, and 30 °C. Seed germination was only affected by temperature and the best result was obtained at 15 °C (71.2%). A significant interaction was found between pre-treatments and incubation temperature with the highest germination percentage (82%) occurred when the seeds soaked in 100 mg L-1 GA3 solution for 30 min and incubated at 20 °C constant temperature. Moreover, the germination speed was fastest from 20 to 25 °C (T50= 9.84 and 9.56 days for 20 and 25 °C, respectively). For asexual propagation, apical stem cuttings were taken at four different periods (4 seasons) and treated with IBA at concentrations of 0, 1000, 2000 and 3000 mg L-1. The cuttings were planted in a peat/perlite mixture 1:1 v/v in plastic square plug trays in order to study the rooting percentage. Winter was the most appropriate season for cuttings collection (100% rooting percentage) and dipping in 1000 or 2000 mg L-1 IBA (72% and 73%, respectively) was the best rooting hormone treatment.

scholarly journals Thermal stress and physiological changes in watermelon seeds

2018 ◽  
Vol 48 (1) ◽  
pp. 66-74 ◽  
Author(s):  
Rita de Cássia Barbosa da Silva ◽  
Marcelo do Nascimento Araujo ◽  
Fábio Luiz Santos Ornellas ◽  
Bárbara França Dantas
Keyword(s):  
Enzyme Activity ◽  
Thermal Stress ◽  
Germination Rate ◽  
Germination Percentage ◽  
Initial Growth ◽  
Physiological Changes ◽  
Percentage Germination ◽  
Stress Protection ◽  
Evaluation Parameters ◽  
The Ideal

ABSTRACT Given that watermelon is a crop widespread around the world, there is considerable interest in verifying how its seeds physiologically behave under unfavorable temperature conditions. This study aimed to evaluate the biochemical changes mobilization and reserves degradation, as well as the enzyme activity, during seed germination and initial growth of watermelon seedlings subjected to thermal stress, using temperature, germination percentage, germination rate and relative germination frequency over the incubation time as evaluation parameters. The experimental design was completely randomized, in a 5 x 3 factorial scheme, with five temperatures (17 ºC, 20 ºC, 25 ºC, 30 ºC and 35 ºC) and three cultivars (Charleston Gray, Fairfax and Crimson Sweet), with 4 replicates of 50 seeds. Germination, seedling growth, reserve degradation and stress protection system were evaluated. Thermal stress caused deleterious effects on watermelon seeds with germination capacity at well defined temperature limits, being 25 ºC the ideal temperature, with the highest percentage of normal seedlings. Sub- (17 ºC) and supra-optimal (30 ºC) temperatures presented more than 80 % of abnormal seedlings. The α-amylase enzyme activity is intense only at the beginning of germination. Under thermal stress, the proline contents increase mainly in the cotyledons.

scholarly journals Dormancy-Breaking and Germination Requirements for Seeds of Sorbus alnifolia (Siebold & Zucc.) K.Koch (Rosaceae), a Mesic Forest Tree with High Ornamental Potential

Forests ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 319
Author(s):  
Yuhan Tang ◽  
Keliang Zhang ◽  
Yin Zhang ◽  
Jun Tao
Keyword(s):  
Seed Dormancy ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Natural Habitat ◽  
Eastern China ◽  
Forest Tree ◽  
Germination Percentage ◽  
Cold Stratification ◽  
Dormancy Breaking ◽  
Breaking Dormancy

Sorbus alnifolia (Siebold & Zucc.) K.Koch (Rosaceae) is an economically important tree in the temperate forests of Eastern China. In recent decades, ever-increasing use and modification of forestlands have resulted in major degeneration of the natural habitat of S. alnifolia. Moreover, S. alnifolia seeds germinate in a complicated way, leading to a high cost of propagation. The current study aimed to determine the requirements for breaking seed dormancy and for germination as well as to characterize the type of seed dormancy present in this species. Moreover, the roles of temperature, cold/warm stratification, and gibberellic acid (GA3) in breaking dormancy were tested combined with a study of the soil seed bank. The results showed that intact seeds of S. alnifolia were dormant, requiring 150 days of cold stratification to achieve the maximum germination percentage at 5/15 °C. Exposure of the seeds to ranges of temperatures at 15/25 °C and 20/30 °C resulted in secondary dormancy. Scarifying seed coat and partial removal of the cotyledon promoted germination. Compared with long-term cold stratification, one month of warm stratification plus cold stratification was superior in breaking dormancy. Application of GA3 did not break the dormancy during two months of incubation. Seeds of S. alnifolia formed a transient seed bank. The viability of freshly matured S. alnifolia seeds was 87.65% ± 11.67%, but this declined to 38.25% after 6-months of storage at room temperature. Seeds of S. alnifolia have a deep physiological dormancy; cold stratification will be useful in propagating this species. The long chilling requirements of S. alnifolia seeds would avoid seedling death in winter.

Allelopathic Effects of Lantana (Lantana camara) on Milkweedvine (Morrenia odorata)

Weed Science ◽  
1984 ◽  
Vol 32 (6) ◽  
pp. 757-761 ◽  
Author(s):  
Nagi Reddy Achhireddy ◽  
Megh Singh
Keyword(s):  
Seed Germination ◽  
Seedling Growth ◽  
Germination Percentage ◽  
Lantana Camara ◽  
Test Period ◽  
Percentage Germination ◽  
Allelopathic Activity ◽  
Foliar Symptoms ◽  
Allelopathic Effects ◽  
Germination And Growth

Allelopathic effects of lantana (Lantana camaraL. ♯3LANCA) residues (root, shoot), foliar leachates, and the soil (where lantana was grown) on milkweedvine (Morrenia odorataLindl. ♯3MONOD) seed germination and growth over a 30-day period were examined. Foliar leachates or the soil collected from the field where lantana had been growing had no effect on the final germination percentage or the seedling growth of milkweedvine. Incorporation of dried lantana shoot or root material into soil had no effect on the final percentage germination but caused significant reductions in milkweedvine growth over a 30-day test period. Roots were more inhibitory than shoots. Fifty percent of milkweedvine seedlings died within 15 days after germination at 1% (w/w) dried lantana root incorporation into the soil, and higher concentrations increased seedling death. Lantana roots incorporated into the soil produced foliar symptoms such as wilting and desiccation, whereas lantana shoots incorporated into the soil produced yellowing of the foliage of milkweedvine. Allelopathic activity of lantana residues was still strong even after decomposition of lantana residues for 4 weeks prior to the planting of milkweedvine seeds.

scholarly journals Factors Affecting Seed Dormancy and Germination of Greater Bur-Parsley (Turgenia latifolia)

2018 ◽  
Vol 36 ◽  
Author(s):  
M. REZVANI ◽  
S.A. SADATIAN ◽  
H. NIKKHAHKOUCHAKSARAEI
Keyword(s):  
Seed Germination ◽  
Environmental Factors ◽  
Seed Dormancy ◽  
Seedling Emergence ◽  
Potassium Nitrate ◽  
Germination Percentage ◽  
Dormancy Breaking ◽  
Planting Depth ◽  
Factors Affecting ◽  
Drought And Salt Stresses

ABSTRACT: Our knowledge about seed dormancy breaking and environmental factors affecting seed germination of greater bur-parsley (Turgenia latifolia) is restricted. This study has addressed some seed dormancy breaking techniques, including different concentrations of gibberellic acid (GA3) and potassium nitrate (KNO3), leaching duration, physical scarification as well as some environmental factors effective on seed germination such as salt and drought stresses, pH and seed planting depth. Seed germination was promoted with lower concentrations of KNO3 (0.01 to 0.02 g L-1), while higher concentrations reduced germination percentage. Seed dormancy was declined by low concentrations of GA3 up to 100 ppm. Seeds of greater bur-parsley germinated in a range of pH from 3 to 7. With enhancement of drought and salt stresses, seed germination decreased. Also, there was no seed germination in a high level of stresses. Seedling emergence reduced as planting depth increased. Use of GA3, KNO3, leaching and physical scarification had a positive effect on seed dormancy breaking of greater bur-parsley. The information from the study increases our knowledge about seed dormancy breaking techniques, response of germination to drought and salt stresses and also determination of distribution regions of greater bur-parsley in the future.

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