scholarly journals Period of time taken by Brachiaria humidicola (Rendle) Scheweick seed to complete germination

2016 ◽  
Vol 37 (2) ◽  
pp. 693
Author(s):  
Camila Aquino Tomaz ◽  
Cibele Chalita Martins ◽  
Givanildo Zildo da Silva ◽  
Roberval Daiton Vieira
Keyword(s):  
Sulfuric Acid ◽  
Seed Dormancy ◽  
Deionized Water ◽  
Final Evaluation ◽  
Dormancy Breaking ◽  
Germination Test ◽  
Brachiaria Humidicola ◽  
Seed Testing ◽  
Breaking Seed Dormancy

The period of 21 days suggested by the Brazilian Rules for Seed Testing for the germination test of B. humidicola seeds seems too long for seed producing companies and laboratories since they depend on the results for decisions concerning the storage or the commercialization of the seed lots. So, the objective of this work was to evaluate the possibility of getting germination results of B. humidicola seeds in a shorter period. The procedures consisted in submitting the seeds to a dormancy breaking treatment and to alternating temperatures during the germination test. Seed samples of nineteen S1 and S2 seed lots were submitted to the following treatments: moistening the germination substratum with 1) deionized water (check treatment), 2) a KNO3 (0.2%) solution, and 3) scarifying the seeds with sulfuric acid for 10 minutes. The germination test was conducted under the conditions of 1) alternating temperatures of 20 and 35 °C and 2) alternating temperatures of 15 and 35 °C both with 8 hours of light. Normal seedlings were evaluated in daily countings. The results showed that the germination test of B. humidicola seeds may be carried out under alternating temperatures of 15 and 35 °C without breaking seed dormancy with a final evaluation of the germination 10 days after the sowing of the seeds.

scholarly journals Methods for overcoming dormancy in Stryphnodendron pulcherrimum seeds

2016 ◽  
Vol 36 (87) ◽  
pp. 195
Author(s):  
Adriano Gonçalves Pereira ◽  
Eniel David Cruz ◽  
Hellen Síglia Demétrio Barros
Keyword(s):  
Sulfuric Acid ◽  
Seed Dormancy ◽  
Aerial Part ◽  
Dry Mass ◽  
Control Treatment ◽  
Tropical Species ◽  
Hard Seeds ◽  
Treatment Data ◽  
Mother Plants ◽  
Breaking Seed Dormancy

Seed dormancy is a phenomenon observed in several tropical species. This condition causes low and non-uniform germination. The present study was designed to identify an efficient method of breaking seed dormancy in Stryphnodendron pulcherrimum. Seeds of four mother plants were subjected to the following treatments: immersion in sulfuric acid for 2, 4, 6, 8, 10 and 12 min and scarification on 150-grit sandpaper. Seeds were sown on substrate containing sand and sawdust (1:1). It was evaluate the days to onset seedlings emergence, seedlings emergence (SE), emergence speed index (ESI), germination (G), hard seeds (HS), dead seeds (DS), dormant seeds (DMS), abnormal seedlings (AS) and dry mass of aerial part (DMAP) and roots (DMR). The experimental design was completely randomized with four replications of 25 seeds for each treatment. Data were subjected to analysis of variance and means compared by Tukey's test (p < 0.05). Significant differences among treatments were observed for ESI, SE, G, HS, DMAP and DMR. Highest HS was observed in control treatment (85%). Highest G was observed in seeds scarified with sulfuric acid for 10 min (82%) and 12 min (74%). These treatments also showed highest ESI, DMAP and DMR, indicating that these scarification treatments were the most efficient in overcoming dormancy.

scholarly journals Techniques for breaking seed dormancy of rainforest species from genus Acronychia

2020 ◽  
Vol 48 (2) ◽  
pp. 159-165
Author(s):  
Ganesha S. Liyanage ◽  
Catherine A. Offord ◽  
Karen D. Sommerville
Keyword(s):  
Gibberellic Acid ◽  
Seed Dormancy ◽  
Seed Coat ◽  
Similar Pattern ◽  
Dormancy Breaking ◽  
Eastern Australia ◽  
Radicle Emergence ◽  
Breaking Seed Dormancy ◽  
Impermeable Seed Coat

We tested for dormancy in three species of Acronychia (Rutaceae) occurring in the rainforest in eastern Australia, A. imperforata, A. laevis and A. oblongifolia, by incubating fresh intact seeds on 0.8% water agar for one month at 25/10°C. Four different techniques were then tested for their effect on dormancy: (i) incubation of intact seeds on agar incorporating gibberellic acid (GA3); (ii) seed coat removal (decoating); (iii) scarification near the radicle emergence point (scarification-emergence point); and (iv) scarification opposite the radicle emergence point (scarification-back). Imbibition tests were performed to determine whether dormancy was due to an impermeable seed coat. Germination differed among treatments, but all three species showed a similar pattern. Intact seeds showed < 6% germination after one month indicating the presence of dormancy. Highest germination (> 65%) was observed following scarification-emergence point treatment. Seed coat removal also resulted in increased germination (40-47%), in comparison with intact seeds, but GA3 and scarification-back treatments did not (< 12%). Though the seedcoats of all species were permeable, increased germination responses to decoating and scarification-emergence point treatments suggest scarification is required to clear the radicle emergence point. This may be a useful dormancy-breaking technique for Acronychia spp. and may be suitable for related Rutaceae species.

scholarly journals Seed anatomy and water uptake and their relation to seed dormancy of Ormosia paraensis Ducke

2018 ◽  
Vol 40 (3) ◽  
pp. 237-245
Author(s):  
Breno Marques da Silva e Silva ◽  
Camila de Oliveira e Silva ◽  
Fabiola Vitti Môro ◽  
Roberval Daiton Vieira
Keyword(s):  
Sulfuric Acid ◽  
Seed Dormancy ◽  
Water Uptake ◽  
Furniture Industry ◽  
Palisade Layer ◽  
Dormancy Breaking ◽  
Physical Dormancy ◽  
Seed Physiology ◽  
Breaking Dormancy ◽  
Hydrophobic Substances

Abstract: Ormosia paraensis Ducke has ornamental seeds widely used in the manufacture of bio-jewels and wood used in the furniture industry. For seedling production, the information on its seed physiology is scarce. Thus, the aim of this study was to assess methods for breaking dormancy and relate them to integument structure and water uptake by O. paraensis seeds. Seed dormancy-breaking was performed by mechanical scarification and soaking in sulfuric acid for 0, 15, 30, 60, 120, and 240 minutes. Dormancy‐broken seeds were compared with intact seeds. Seed integument is formed by a cuticle (hydrophobic substances), epidermis (macroesclereids of the palisade layer,), hypodermis (osteosclereids), and parenchyma cells. Intact seeds did not absorb water after 72 hours of soaking. The highest percentages and rates of seed germination were observed in treatments with mechanical scarification and soaking in sulfuric acid for 60 or 120 minutes. Seed soaking in sulfuric acid (H2SO4 p.a. 98.08%) for 60 or 120 minutes or mechanical scarification are adequate to overcome physical dormancy associated with O. paraensis seed integument impermeability to water or gases.

scholarly journals TIME REDUCTION FOR SURINAM GRASS SEED GERMINATION TEST

2015 ◽  
Vol 39 (5) ◽  
pp. 488-497 ◽  
Author(s):  
Camila de Aquino Tomaz ◽  
Cibele Chalita Martins ◽  
Mauricio Feis Ganz Sanches ◽  
Roberval Daiton Vieira
Keyword(s):  
Sulfuric Acid ◽  
Segmented Regression ◽  
Dormancy Breaking ◽  
Germination Test ◽  
Parameter Estimations ◽  
Seed Analysis ◽  
Seed Germination Test ◽  
Segmented Regression Model ◽  
Seed Water Content ◽  
The Ideal

ABSTRACTThe period for the germination test of Surinam grass seeds established by the Rules for Seeds Testing is 28 days, considered too lengthy by producers, venders, and seed analysis laboratories. So, the objective of this research was to evaluate the possibility of reducing the time for the germination test of Surinam grass seeds and to establish a method for dormancy breaking and the ideal temperature. Ten seed lots were submitted to the following treatments to overcome seed dormancy: control; substrate moistening with 0.2% KNO3; and scarification with sulfuric acid (98% 36 N) for 15 minutes. After the treatments, the lots were submitted to seed water content, germination and tetrazolium tests. During the germination test, conducted with four replicates of 100 seeds per treatment for 28 days, two conditions of alternating temperatures (20-35 °C and 15-35 °C) with 8 hours of light were tested. Attempting to determine the test end date, daily counts of the number of normal seedlings were made and for each lot, treatment, and temperature, a growth curve for the evaluation of germination was adjusted. The segmented regression model parameter estimations were calculated for each treatment. The germination test of Braquiaria decumbensseeds may be evaluated in 12 days after sowing using alternating temperatures of 20-35 °C and without any treatment to overcome dormancy.

Seed treatments alleviate dormancy of field bindweed (Convolvulus arvensisL.)

2018 ◽  
Vol 32 (5) ◽  
pp. 564-569 ◽  
Author(s):  
Renci Xiong ◽  
Ying Wang ◽  
Hanwen Wu ◽  
Yan Ma ◽  
Weili Jiang ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Seed Germination ◽  
Seed Dormancy ◽  
Soil Seed Bank ◽  
Hot Water ◽  
Clear Understanding ◽  
Cold Stratification ◽  
Radicle Growth ◽  
Field Bindweed ◽  
Breaking Seed Dormancy

AbstractField bindweed, a member of the Convolvulaceae family, is a problematic perennial weed in cotton fields and orchards in northwest China. The species exhibits strong seed dormancy, causing delayed germination. A clear understanding of the mechanisms involved in alleviating seed dormancy is important for effective plant propagation and successful management of field bindweed. Experiments were conducted to investigate seed germination and radicle growth of field bindweed by breaking seed dormancy using mechanical scarification, sulfuric acid, hot-water scarification, cold stratification, and chemical treatment. Chemical treatments (gibberellic acid or potassium nitrate) had no effect on breaking seed dormancy, whereas mechanical scarification (sandpaper and blade) resulted in 92% to 98% seed germination, indicating that seed dormancy of field bindweed was mainly due to the presence of a hard seed coat. Seeds pretreated with 80% sulfuric acid for 15 to 60 min or 98% sulfuric acid for 15 to 30 min had germination rates above 80%, and soaking seeds in 70 C water for 4 to 16 min or in boiling water for 5 to 20s were effective in breaking seed dormancy but had no effect on the radicle growth of field bindweed. Cold stratification at 5 C for 2 to 8wk partially accelerated seed dormancy release, resulting in 53% to 67% seed germination. Results indicated that field bindweed could potentially form a persistent soil seed bank with physically dormant seed; therefore, strategies for eliminating seed production should be adopted.

scholarly journals Studies on Seed Dormancy Breaking in Cucumber (Cucumis sativus L.) Variety Poinsett

2021 ◽  
pp. 124-129
Author(s):  
H. Usha Nandhini Devi ◽  
J. Renugadevi ◽  
V. Rajasree ◽  
L. Pugalendhi
Keyword(s):  
Cucumis Sativus ◽  
Seed Dormancy ◽  
Block Design ◽  
Germination Percentage ◽  
Quality Parameters ◽  
Seedling Quality ◽  
Dormancy Breaking ◽  
Germination Test ◽  
Cucumis Sativus L ◽  
Vigor Index

Experiments were carried out to study the effect of chemicals in breaking the dormancy of cucumber. The study was conducted at the Department of Vegetable Science, Horticultural College and Research Institute, Coimbatore during 2017-2018. The seeds of cucumber variety Poinsett were treated with various chemicals immediately after harvest to standardize the best dormancy breaking treatment. The design of the experiment was Factorial Randomised Block Design with two replications. The seeds were treated with the chemicals for 12 hrs and 24 hours duration. The germination test was conducted. Observations on seed and seedling quality parameters viz., speed of germination, and germination percent, vigor index I and vigor index II were recorded. At 12 hours duration, the highest speed of germination (23.29) was recorded in T2 (GA3150 ppm) whereas the highest germination percentage (92) was recorded in T8 (Ethrel150 ppm). At 24 hours duration, the highest speed of germination (30.77) and the highest germination percentage (86) was observed in T12 (KNO3500 ppm). At 12 hours duration, the highest Vigor Index I (2800.16) was recorded in T9 (Ethrel 500 ppm) while the vigor Index II was the highest (12.19) in T8 (Ethrel150 ppm). At 24 hours duration, the highest Vigor Index I (2349.28) was observed in T10 (Ethrel 1000 ppm) while the vigor Index II was the highest (14.066) in T11 (KNO3150 ppm).

AN IMPROVED METHOD FOR BREAKING DORMANCY IN SEEDS OF SESBANIA SESBAN

2008 ◽  
Vol 44 (2) ◽  
pp. 185-195 ◽  
Author(s):  
Y. R. WANG ◽  
J. HANSON
Keyword(s):  
Water Temperature ◽  
Seed Dormancy ◽  
Seed Coat ◽  
Phase 1 ◽  
Sesbania Sesban ◽  
Germination Test ◽  
Two Phase ◽  
Hard Seed ◽  
Hard Seeds ◽  
Breaking Seed Dormancy

SUMMARYDormancy in seeds of Sesbania sesban is caused by a water-impermeable seed coat (hard seeds or hardseededness). A two-phase pretreatment technique was developed for breaking seed dormancy and was validated using different accessions and seed lots. Seeds were first soaked in water at 80 °C for 8 min and prepared for the germination test. Ungerminated hard seeds at the first count (after four days incubation) during the germination test were then subjected to a second treatment by mechanically scarifying the seed coat. The effects of water temperature and variation in initial hardseededness and viability among and within accessions were also investigated. The optimum water temperature, allowing maximum seed germination without increasing the percentage of abnormal seedling/dead seeds was 80 °C. The mean percentage of hard seeds across 30 seed lots of six accessions was reduced to 26% after phase 1 and to 0% after phase 2. In addition, full germination occurred within only 10 days for treated seeds while germination in untreated seeds had reached only 48% after 14 days. Significant differences existed among the seed lots within the accessions (p > 0.05) for the percentage of initial hard seed and for the effects of treatments on breaking seed dormancy. The two-phase technique developed was validated using over 1000 seed lots of S. sesban, and it was found to be a rapid and cost-effective method for breaking hard seed dormancy with potential for wider use for hard-seeded legumes.

scholarly journals Dormancy Breaking and the Influence of Gibberellic Acid on the Early Growth of Tamarindus indica Seedlings in Mubi, Nigeria

2019 ◽  
pp. 1-6
Author(s):  
S. C. Yusuf ◽  
N. N. Zakawa ◽  
T. D. Tizhe ◽  
D. Timon ◽  
J. J. Obot ◽  
...  
Keyword(s):  
Gibberellic Acid ◽  
Seed Dormancy ◽  
Water Uptake ◽  
Cold Water ◽  
Germination Percentage ◽  
Early Growth ◽  
Tamarindus Indica ◽  
Dormancy Breaking ◽  
Number Of Leaves ◽  
Breaking Seed Dormancy

The purpose of this research was to determine the appropriate methods of breaking seed dormancy, level of water uptake, and the influence of gibberellic acid on the early growth of Tamarindus indica seedlings. The scarification methods used included: concentrated sulphuric acid (H2SO4), manual scarification, flaming, hot and cold water treatments. The experiments were conducted in the laboratory on Petri dishes and in potting media. GA3 was used to optimize the production of seedlings by spraying the solution on the foliage. The treatment for 10 minutes with concentrated H2SO4 gave the maximum germination percentage and water uptake (80.41%). GA3 enhances the growth of the seedlings by increasing the height, the number of leaves and stem girth at eight weeks after sowing. In conclusion, all the scarification treatments applied to the seeds of T. indica proved effective. The ten minutes treatment with concentrated H2SO4 was the best treatment for breaking seed dormancy of T. indica. And gibberellic acid enhanced early and fast seedling growth as it increase height, number of leaves and stem girth of T. indica.

Heat shock, smoke and darkness: partner cues in promoting seed germination in Epacris tasmanica (Epacridaceae)

2000 ◽  
Vol 48 (5) ◽  
pp. 603 ◽  
Author(s):  
Craig A. Gilmour ◽  
Ronald K. Crowden ◽  
Anthony Koutoulis
Keyword(s):  
Heat Shock ◽  
Seed Germination ◽  
Effective Treatment ◽  
Seed Dormancy ◽  
Inhibitory Effect ◽  
Dormancy Breaking ◽  
Seasonal Drought ◽  
Breaking Seed Dormancy ◽  
Tasmanian Endemic

The Epacridaceae is one of the families that dominate Australian heathlands, environments prone to disturbance events such as fire and seasonal drought. To investigate the role of fire-related cues in breaking seed-dormancy mechanisms in the Epacridaceae, the influences of heat shock, darkness, direct smoke and varying concentrations of aqueous smoke solutions (5, 10 and 100%) on seed germination of the Tasmanian endemic Epacris tasmanica were examined. A small fraction (5.3%) of non-dormant E. tasmanica seed could germinate in the absence of fire-related cues. The most effective treatment for promoting seed germination was direct smoke (74.67%); however, germination with direct smoke was delayed by about two weeks when compared to other significant treatments, suggesting an initial inhibitory effect. Significant interactions were recorded between all classes of treatments (heat shock, darkness and smoke solutions), with treatments acting sequentially and additively to promote germination. The most effective combinatory treatment tested was 5% smoked water (5%S) in conjunction with darkness (D) and heat-shock (H) treatments (5%SDH), which raised germination levels to 49%. In the absence of heat shock, darkness and various concentrations of smoked water had no significant effect on seed germination. The 5%SDH treatment promoted seed germination significantly also in two wet-heathland (E. lanuginosa (42.7%) and E. obtusifolia (64.7%)) and two dry-heathland Epacris species (the Tasmanian endemic E. apsleyensis (72.7%) and the rare mainland Australian E. purpurascens (75%)). The results of this study indicate that fire-related dormancy-breaking cues act synergistically in promoting seed germination in E. tasmanica and suggesting that their level of influence may reflect the ecology of Epacris species.

Breaking Seed Dormancy in Corchorus olitorius Landraces

Planta Medica ◽  
2008 ◽  
Vol 74 (03) ◽  
Author(s):  
AE-D Helaly ◽  
H Al-Amier ◽  
AA Al-Aziz ◽  
LE Craker
Keyword(s):  
Seed Dormancy ◽  
Corchorus Olitorius ◽  
Breaking Seed Dormancy
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