scholarly journals Optimization of Waltheria indica Seed Dormancy Relief Treatments and Seed Storage Parameters

HortScience ◽  
2016 ◽  
Vol 51 (9) ◽  
pp. 1184-1187
Author(s):  
Scott B. Lukas ◽  
Joseph DeFrank ◽  
Orville C. Baldos
Keyword(s):  
Seed Dormancy ◽  
Large Scale ◽  
Heat Exposure ◽  
Seed Storage ◽  
Hot Water ◽  
Physical Dormancy ◽  
Dry Heat ◽  
Long Term Storage ◽  
Viable Seeds ◽  
Temperature Exposure

In Hawaii, Waltheria indica (uhaloa) has been identified for expanded usage as a roadside groundcover in lowland dry ecosystems. Seed dormancy through lack of germination of viable seeds was identified in uhaloa. The presence of physical dormancy in uhaloa seeds was determined and dormancy relief methods were evaluated including hand scarification, dry heat temperature exposure, hot water exposure, and mechanical abrasion in an electric drum scarifier. As a compliment to dormancy relief, long-term storage parameters were evaluated for scarified and nonscarified seeds. The elucidation of physical dormancy was determined through hand scarification, resulting in 96% germination compared with 8% of nonscarified seeds, but is not practical on a large-scale basis. The greatest practical dormancy relief was achieved with a mechanical electric drum scarifier lined with 80-grit sandpaper for a duration of 15 or 30 seconds producing 95% and 99% germination, respectively. Seeds immersed in boiling water for 3 and 5 seconds resulted in 58.6% and 57.7% germination, respectively. Dormancy relief through dry heat exposure was inferior to other relief methods, producing 39% germination at 75 °C for 60 minutes. Nonscarified seeds exhibited minimal loss of viability during 10 months of storage at 5 °C at 12% and 50% relative humidity (RH), but a significant decline in viability of scarified seeds was detected.

Mechanisms of seed dormancy in an annual population of Zostera marina (eelgrass) from The Netherlands

1991 ◽  
Vol 69 (9) ◽  
pp. 1972-1976 ◽  
Author(s):  
Paul Garth Harrison
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Seed Coat ◽  
Zostera Marina ◽  
Early Winter ◽  
Physical Dormancy ◽  
Physiological Dormancy ◽  
Annual Population ◽  
Effects Of Temperature ◽  
Viable Seeds

Mechanisms of dormancy of seeds from an annual population of the seagrass Zostera marina L. (eelgrass) in the SW Netherlands were investigated in the laboratory. Both physiological dormancy (a requirement for reduced salinity for germination) and physical dormancy (imposed by the seed coat) existed in recently shed seeds. Physiological seed dormancy was partly released in the seed bank by early winter, but physical dormancy lasted longer. By March seeds germinated quickly in the dark in full-strength seawater without artificial weakening of the seed coat. Viable seeds were released with coats that ranged from green (easily ruptured by the embryo) to brown (not easily ruptured); this variation may account for the occasional seedlings that appear during winter. No significant effects of temperature or light on germination were detected. A reexamination of the literature suggests that the observed variation in timing of germination in eelgrass populations may be a result of hitherto overlooked aspects of dormancy. Key words: eelgrass, seagrass, seed coat, seed dormancy, seed germination, Zostera marina.

scholarly journals SEED DORMANCY BREAKING TREATMENTS FORAFRICAN PURSLANE (Zaleya pentandra)

2015 ◽  
Vol 33 (4) ◽  
pp. 623-629 ◽  
Author(s):  
S. MUNAWAR ◽  
M. NAEEM ◽  
H.H. ALI ◽  
M. JAMIL ◽  
M. IQBAL ◽  
...  
Keyword(s):  
Seed Dormancy ◽  
Arid Zone ◽  
Hot Water ◽  
Plant Management ◽  
Dormancy Breaking ◽  
Invasive Weed ◽  
Hard Seed ◽  
Dry Heat ◽  
Breaking Dormancy ◽  
Seed Scarification

ABSTRACT Understanding the mechanisms involved in releasing seed dormancy is crucial for effective plant management and renewal of species in the arid zone. Zaleya pentandra is an emerging invasive weed of the arid areas of Pakistan. We investigated the effects of different dormancy breaking treatments on the germination of Z. pentandra seeds. Seeds were treated with hot water (by placing them in boiling water for 5, 15, 30, 60, 90, 120, and 150 min), dry heat (by placing them in a preheated oven at 70 oC for 1, 2, and 4 hours; at 70 oC for 1, 2, 3, and 4 days, and at 200 oC for 5, 10, 15, 30, and 45 min) and stratification (by placing them at 2-5 ºC in a refrigerator for 5, 10, 30, and 60 min; for 3, 6, and 12 hours, and for 1, 2, 4, 8, 15, and 30 days). Seeds also were soaked in thiourea ([(NH2)2CS] (0, 2,500, 5,000, 7,500, and 10,000 mg L-1 for 24 h at 30 oC) and in KNO3 (0, 10,000, 20,000, 30,000, 40,000, 50,000, and 60,000 mg L-1 for 24 h at 30 oC). Additionally, seeds were scarified with HCl (for 3, 6, 9, 12, 15, 18, and 21 h), HNO3 (for 3, 6, 9, 12, 15, 18, and 21 h), and H2SO4 (for 20, 40, 60, 80, 100, and 120 min at 30 oC) and also mechanically scarified with sandpaper. Zaleya pentandra seeds showed typical signs of hard seed coat dormancy. Mechanical scarification and acid treatments promoted seed germination to a varying degree. Seed scarification with HNO3 for 12 to 18 h as well as with HCl for 12 h and 15 h was efficient in breaking dormancy of Z. pentandra seeds, providing germination up to 92.5%. Seed scarification with H2SO4 from 20 to 120 min showed little effect, whereas hot water, dry heat, stratification and various concentrations of thiourea and KNO3 were ineffective in breaking Z. pentandra seed dormancy.

Physical dormancy in seeds of six genera of Australian Rhamnaceae

2005 ◽  
Vol 15 (1) ◽  
pp. 51-58 ◽  
Author(s):  
S.R. Turner ◽  
D.J. Merritt ◽  
C.C. Baskin ◽  
K.W. Dixon ◽  
J.M. Baskin
Keyword(s):  
Seed Dormancy ◽  
Restoration Ecology ◽  
Hot Water ◽  
Optimum Temperature ◽  
Physical Dormancy ◽  
South West ◽  
Temperature Regimes ◽  
High Germination

Physical dormancy (PY) was identified in six genera representative of Australian Rhamnaceae and subsequently was broken, based on identification of key seed dormancy characteristics: (1) isolation and classification of embryo features; (2) imbibition experiments to determine the rate and amount of water uptake in seeds; and (3) determination of optimum temperature regimes for germination. All six species had relatively large spatulate embryos. Imbibition studies showed all species possessed PY (i.e. a water-impervious seed coat) that was broken by a hot-water treatment. Alleviation of PY resulted in high germination (<70%) at 7/18°C, temperatures similar to winter in south-west Western Australia. Germination was suppressed at higher temperatures and in the presence of light. The study adds information to our knowledge of seed dormancy in Australian Rhamnaceae, and highlights the benefits of understanding dormancy states in seeds prior to evaluating dormancy-release mechanisms on wild species used in restoration ecology and horticulture.

scholarly journals Polyphenols leaching and seed dormancy in carob (Ceratonia siliqua L.) in relation to hot water treatment

2021 ◽  
Vol 43 (11) ◽  
Author(s):  
Valeria Cavallaro ◽  
Carmelo Maucieri ◽  
Cristina Patanè ◽  
Giancarlo Fascella ◽  
Alessandra Pellegrino ◽  
...  
Keyword(s):  
Sulphuric Acid ◽  
Seed Dormancy ◽  
Seed Coat ◽  
Large Scale ◽  
Hot Water ◽  
Ceratonia Siliqua ◽  
Seed Treatments ◽  
Total Polyphenols ◽  
Ceratonia Siliqua L ◽  
Large Scale Cultivation

AbstractCarob (Ceratonia siliqua L.) is a relevant element of the Mediterranean spontaneous vegetation. Moreover, it is useful in reforestation, and it is currently re-valued for sustainable agriculture in dryland areas. However, the difficulties tied to carob propagation (mainly seed dormancy) hamper its large-scale cultivation. In this paper, the effects of four seed treatments (no treatment [control], soaking at 70 °C and 90 °C in water, or in 96% sulphuric acid) on five carob genotypes germination were studied. As compared to the very low germination of untreated seeds (0–13% germination), sulphuric acid (93–100% germination) and 90 °C water soaking (from 72 to > 90% germination in four out the five genotypes) were effective in promoting germination. Soaking at 90 °C resulted in the leaching of a higher amount of total polyphenols from the genotypes seed coat as compared to soaking at 70 °C. A significant correlation (0.75**) was ascertained between polyphenol leaching of the different genotypes and germination. These results suggest that dormancy in this species is not primarily associated with seed coat hardness, as it is generally thought, but also with the release of polyphenols. Polyphenols determination of the dormant and the few non-dormant seeds of the different genotypes also seem to confirm this hypothesis since these last showed an almost halved total polyphenols content (on average 17.0) as compared to dormant ones (34.8 mg g−1 of seed FW). Further studies may determine the polyphenols involved, but also assess new, easier to carry out, seed treatments. The important role of the galactomannans on seed germination of carob is also discussed. Finally, similar studies may enhance the knowledge of dormancy processes in other Fabaceae species whose germination is positively affected by hot water treatments.

scholarly journals Carnivore endozoochory of a dry-fruited tree can benefit quarry passive restoration

2019 ◽  
Author(s):  
Vânia Salgueiro ◽  
Carmo Silva ◽  
Sofia Eufrázio ◽  
Pedro Salgueiro ◽  
Pedro G. Vaz
Keyword(s):  
Large Scale ◽  
Tap Water ◽  
Seedling Emergence ◽  
Survival Rates ◽  
Experimental Studies ◽  
Sowing Date ◽  
List Type ◽  
Physical Dormancy ◽  
Passive Restoration ◽  
Viable Seeds

AbstractAs more work assert passive restoration as a complementary approach to technical reclamation, it is imperative to know its drivers. Although the consequences of endozoochory are crucial to predict passive restoration success, few experimental studies assess the use of heavily disturbed sites by seed dispersers such as carnivores and how the seeds they bring in emerge and survive. Using an indoor sowing experiment conductedin situ, we examined for the first time how carnivore endozoochorous seeds collected in a quarry potentially influence its passive restoration, through effects on plant emergence and survival. Also, we tested whether sowing date and water soaking, relevant factors when sowings are to be carried out, would affect seedling emergence and survival rates when compared with the effect of endozoochory. Most interesting in our analysis were the results for Carob tree (Ceratonia siliqua), a dry-fruited species being used in an ongoing action of artificial revegetation of this quarry located within a natural park in Portugal. Irrespective of the carnivore species, endozoochorous carob seeds collected in the quarry performed similarly to untreated seeds regarding emergence rates. Endozoochorous carob seedlings showed greater mortality rates but the net result for the plant can still be the colonization of recently vacant habitats by a large proportion of viable seeds. The later carob seeds were sown, the faster seedlings emerged, including endozoochorous seedlings. As expected, water soaking implied faster emergences. Broadly, plantings, sowings with previous soaking, and carnivore-mediated seed dispersal of this dry-fruited tree can jointly enhance quarry restoration.Implications for practiceRestorers can undertake pilot sowing experiments similar to ours prior to large scale revegetation campaigns to identify which species can benefit the most from endozoochory.Carnivores in the surroundings of a quarry contribute a large proportion of viable seeds, likely assisting quarry passive restoration.Carnivores ingesting carob seeds later in the fruiting season may assist quarry passive revegetation more readily as seeds ingested around that time emerge earlier.Immersion in tap water seems to be a simple, inexpensive, and a highly efficient method to break physical dormancy when carob seed sowings are to be carried out in degraded sites.

scholarly journals Effect of physical and chemical treatments on breaking the seed dormancy of Caesalpinia bonduc (L.) Roxb.

2021 ◽  
Vol 8 (3) ◽  
Author(s):  
J Jaya Rathi ◽  
R Sasirekha ◽  
R Ranjith Kumar
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Seed Dormancy ◽  
Growth Regulators ◽  
Inorganic Compounds ◽  
Hot Water ◽  
Medicinal Uses ◽  
Chemical Treatments ◽  
Dry Heat ◽  
Physical And Chemical

Caesalpinia bonduc (L.) Roxb. is a medicinal plant belonging to the family Caesalpiniaceae was used for the present study. It is a prickly shrub widely distributed all over the world. Keeping the economic and social medicinal uses of C. bonduc seeds are being used widely in Folk, Ayurvedha, Siddha, Unani medicines to treat skin disease, eyesores, cancer, asthma, tuberculorosis, fever, toothaches etc. The aim of this study is to determine the requirements for breaking seed dormancy and germination of C. bonduc. The germination is prevented due to hard seed coat. C. bonduc seeds were experimented with various physical and chemical treatments to break the dormancy. The seeds were subjected to various treatments like mechanical scarification, dry heat method, light, hot water, acid scarification, inorganic compounds, plant growth regulators etc. The seeds treatment with mechanical scarification at 50, 40 and 30 seconds showed 100%, 80% and 10% of germination, whereas no changes was observed in dry heat. White light treatment showed 100% germination at 48 hrs, whereas darkness and red light showed least germination of about 10%. The hot-water treatment showed 100% germination. In chemical treatments, concentrated sulphuric acid scarification showed highest germination percentage, whereas lowest germination was found in nitric acid. Among the plant growth regulators, Gibberellic acid showed 100% germination whereas 2-isopentyl adenine showed least germination of 10% at 50 ppm. Results of this study prove that mechanical scarification was the most effective treatment to overcome dormancy of seeds in C. bonduc.

Seed dormancy in four Tibetan Plateau Vicia species and characterization of physiological changes in response of seeds to environmental factors

2013 ◽  
Vol 23 (2) ◽  
pp. 133-140 ◽  
Author(s):  
Xiaowen Hu ◽  
Tingshan Li ◽  
Juan Wang ◽  
Yanrong Wang ◽  
Carol C. Baskin ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Seed Dormancy ◽  
Germination Rate ◽  
Soil Surface ◽  
The Tibetan Plateau ◽  
Physical Dormancy ◽  
High Germination ◽  
One Year ◽  
Hydrotime Model ◽  
Aba Biosynthesis

AbstractAlthough seed dormancy of temperate legumes is well understood, less is known about it in species that grow in subalpine/alpine areas. This study investigated dormancy and germination of four Vicia species from the Tibetan Plateau. Fresh seeds of V. sativa were permeable to water, whereas those of V. angustifolia, V. amoena and V. unijuga had physical dormancy (PY). One year of dry storage increased the proportion of impermeable seeds in V. angustifolia, but showed no effect on seed coat permeability in V. amoena or V. unijuga. Seeds of all four species also had non-deep physiological dormancy (PD), which was especially apparent in the two annuals at a high germination temperature (20°C). After 1 year of storage, PD had been lost. The hydrotime model showed that fresh seeds obtained a significantly higher median water potential [Ψb(50)] than stored seeds, implying that PD prevents germination in winter for seeds dispersed without PY when water availability is limited. After 6 months on the soil surface in the field, a high proportion of permeable seeds remained ungerminated, further suggesting that PD plays a key role in preventing germination after dispersal. Addition of fluridone, an inhibitor of abscisic acid (ABA) biosynthesis, evened-out the differences in germination between fresh and stored seeds, which points to the key role of ABA biosynthesis in maintaining dormancy. Further, fresh seeds were more sensitive to exogenous ABA than stored seeds, indicating that storage decreased embryo sensitivity to ABA. On the other hand, the gibberellic acid GA3 increased germination rate, which implies that embryo sensitivity to GA is also involved in seed dormancy regulation. This study showed that PY, PD or their combination (PY+PD) plays a key role in timing germination after dispersal, and that different intensities of dormancy occur among these four Vicia species from the Tibetan Plateau.

The potential of the smoke-derived compound 3-methyl-2H-furo[2,3-c]pyran-2-one as a priming agent for tomato seeds

2007 ◽  
Vol 17 (3) ◽  
pp. 175-181 ◽  
Author(s):  
Neeru Jain ◽  
Johannes Van Staden
Keyword(s):  
Large Scale ◽  
Seed Storage ◽  
Seed Priming ◽  
Stress Conditions ◽  
Scale Production ◽  
Seedling Vigour ◽  
Flow Cytometry Data ◽  
Tomato Seeds ◽  
Vigour Index ◽  
Continuous Presence

AbstractThe stimulatory role of 3-methyl-2H-furo[2,3-c]pyran-2-one, a smoke-derived butenolide, on germination and post-germination events is well documented. Previous studies have involved germinating seeds in the continuous presence of the compound. However, commercial growers cannot exploit the potential of the butenolide for large-scale production of crops due to limited availability and environmental constraints. The present study was undertaken to assess the potential of the butenolide as a priming agent of tomato (Solanum esculentum Mill.) seeds. Flow cytometry data revealed that butenolide-primed seeds had a higher percentage of nuclei at the 4C stage than water-primed seeds. Emergence of the radicle was much faster in the primed seeds. After 36 h of imbibition, a higher percentage of the butenolide-primed seeds (22%) exhibited radicle emergence compared to the water-primed seeds (12%). While butenolide-primed seeds initially germinated more rapidly than either water-primed or unprimed seeds in a 48-h period, water-imbibed seeds reached a similar germination level as the butenolide-primed seeds by 60 h of incubation. The butenolide-primed seeds produced significantly (P ≤ 0.05) more vigorous seedlings than water-primed seeds or seeds in the continuous presence of either water or butenolide. A gradual decrease in the seedling vigour index was recorded for both water and butenolide-primed seeds with increased seed storage at room temperature. Nevertheless, the vigour index was significantly greater in the butenolide-primed seeds than the water-primed seeds. Vigour indices were significantly (P ≤ 0.05) higher for the butenolide-primed seeds under various stress conditions (salinity, osmoticum or temperature) compared to control or water-primed seeds. Results of the present study suggest that the butenolide is a good seed-priming agent. Additionally, primed seeds retained the promotive effect for a considerable time. This was also the case for tomato seeds under various simulated field stress conditions.

Seed germination biology of sweet acacia (Vachellia farnesiana) and response of its seedlings to herbicides

Weed Science ◽  
2021 ◽  
pp. 1-19
Author(s):  
Bhagirath S. Chauhan ◽  
Shane Campbell ◽  
Victor J. Galea
Keyword(s):  
Sodium Chloride ◽  
Seed Germination ◽  
Development Stage ◽  
Hot Water ◽  
Control Treatment ◽  
Similar Species ◽  
Weed Species ◽  
Physical Dormancy ◽  
Seed Biology ◽  
Wide Range

Abstract Sweet acacia [Vachellia farnesiana (L.) Willd.]is a problematic thorny weed species in several parts of Australia. Knowledge of its seed biology could help to formulate weed management decisions for this and other similar species. Experiments were conducted to determine the effect of hot water (scarification), alternating temperatures, light, salt stress, and water stress on seed germination of two populations of V. farnesiana and to evaluate the response of its young seedlings (the most sensitive development stage) to commonly available POST herbicides in Australia. Both populations behaved similarly to all the environmental factors and herbicides; therefore, data were pooled over the populations. Seeds immersed in hot water at 90 C for 10 min provided the highest germination (88%), demonstrating physical dormancy in this species. Seeds germinated at a wide range of alternating day/night temperatures from 20/10 C (35%) to 35/25 C (90%) but no seeds germinated at 15/5 C. Germination was not affected by light, suggesting that seeds are nonphotoblastic and can germinate under a plant canopy or when buried in soil. Germination was not affected by sodium chloride concentrations up to 20 mM and about 50% of seeds could germinate at 160 mM sodium chloride, suggesting its high salt tolerance ability. Germination was only 13% at −0.2 MPa osmotic potential and no seeds germinated at −0.4 MPa, suggesting that V. farnesiana seeds may remain ungerminated until moisture conditions have become conducive for germination. A number of POST herbicides, including 2,4-D + picloram, glufosinate, paraquat and saflufenacil, provided >85% control of biomass of young seedlings compared with the nontreated control treatment. Knowledge gained from this study will help to predict the potential spread of V. farnesiana in other areas and help to integrate herbicide use with other management strategies.

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