scholarly journals Germination of Crotalaria and Lupinus (Fabaceae) seeds submitted to different pre-germination treatments and their effect on enzymatic activity during early germination

2020 ◽  
Vol 80 (1) ◽  
pp. 23-29
Author(s):  
B. Garduza-Acosta ◽  
L. C. Lagunes-Espinoza ◽  
C. C. Bautista-Muñoz ◽  
G. García-de-los-Santos ◽  
J. M. Zaldívar-Cruz ◽  
...  
Keyword(s):  
Enzymatic Activity ◽  
Total Protein ◽  
Germination Percentage ◽  
Hot Water ◽  
Galactosidase Activity ◽  
Physical Dormancy ◽  
Legume Seeds ◽  
Specific Enzymatic Activity ◽  
Early Germination ◽  
Native Legume

Abstract Most of the wild and native legume seeds has a hard and impermeable testa, which causes physical dormancy and prevents them from germinating even when environmental conditions are favorable. The study evaluated the effect of scarification treatments on germination and enzymatic activity of Crotalaria longirostrata (Cl) and Lupinus exaltatus (Le) seeds. After scarification treatments, germination percentage (GP) and rate (GR) were assessed during 30 days after seeding (DAS); and water absorption (WA) and specific enzymatic activity (SEA) during early germination (0, 6, 18, 36, 72, 120 h) in a growing chamber at 25 °C and photoperiod of 12 h. Scarification with 98% H2SO4 15 min increased GP and GR in both species. At 30 DAS, GP and GR of Le seeds were 34% and 0.97 seeds day-1, respectively. In Cl seeds, GP was 64% and GR 0.90 seeds day-1. Scarification with H2O at 80 °C 1 min also promoted germination in Cl (52%). At 120 h after seeding, Le and Cl seeds showed already a high GP with acid scarification (31% and 48%, respectively). In seeds of both species, scarification treatments affected WA and SEA during early germination. During this period, scarification treatments that increased GP also showed a higher α-D-galactosidase activity. The maximum enzyme activity was observed 72 h after hot water scarification in Cl (82.6 U/mg total protein), followed by acid scarification (54.5 U/mg total protein). In Le, the activity peak was 36 h after acid scarification (9.5 U/mg total protein). No relationship was observed between β-glucosidase activity and GP in both species. In conclusion, during early germination of both species, the increase in GP is accompanied by a rise in α-D-galactosidase activity between 36 and 72 h after seeding; and in Cl seeds, an alternative scarification treatment to increase GP may be the use of hot water.

Seasonal influence on dormancy alleviation inDodonaea viscosa(Sapindaceae) seeds

2014 ◽  
Vol 24 (3) ◽  
pp. 229-237 ◽  
Author(s):  
Ganesh K. Jaganathan ◽  
Baolin Liu
Keyword(s):  
Water Treatment ◽  
Storage Temperature ◽  
Soil Layer ◽  
Germination Percentage ◽  
Hot Water ◽  
Natural Environments ◽  
Hot Water Treatment ◽  
Physical Dormancy ◽  
High Summer Temperature ◽  
The Tropics

AbstractSeeds ofDodonaea viscosa(Sapindaceae) have a water-impermeable seed coat, i.e. physical dormancy (PY). Although mechanical scarification, dry heat, sulphuric acid and hot water treatment make seeds permeable under laboratory conditions, the mechanisms by which dormancy is alleviated in natural environments have not yet been understood completely. The present investigation aims to understand the pattern of dormancy alleviation inD. viscosaseeds using an artificial burial approach for 2 years. Freshly collected seeds held in hydrated soil at 10/20°C, 15/20°C, 15/30°C, 20/35°C and 25°C for 32 weeks germinated to less than 15%, irrespective of storage temperature. Dry storage of seeds at 15, 20, 25 and 30°C for 1 year did not break dormancy. Hot water treatment at 80 and 90°C for 30 s broke dormancy in 90% of the seeds. On the other hand, burying seeds at a depth of 3–5 cm in the natural environment for 2 years increased germination from 7 to 71%. In particular, seeds exhumed after summer in both years showed a significant increase in germination percentage(P< 0.05). However, seeds buried after summer did not germinate to a higher percentage when exhumed prior to summer. We suggest that a high summer temperature, rising above 60°C in the top soil layer of the tropics, is a likely factor breaking dormancy. Most seeds germinated during burial, which indicates that light is not a cue for germination. We conclude that germination ofD. viscosafollowing summer is an adaptive mechanism to tolerate summer droughts, which are common in the dry tropics.

scholarly journals Effects of Aeschynomene histrix Poir. seed treatment on germination

2021 ◽  
pp. 247-252
Author(s):  
Bignon Daniel Maxime Houndjo ◽  
Sébastien Adjolohoun ◽  
Dourossimi Adam Adenile ◽  
Marcel Houinato ◽  
Brice Augustin Sinsin
Keyword(s):  
Seed Germination ◽  
Seed Treatment ◽  
Seedling Emergence ◽  
Germination Percentage ◽  
Hot Water ◽  
Physical Dormancy ◽  
Cattle Faeces ◽  
The Subject ◽  
Number Of Seeds ◽  
Three Phases

Description of the subject. Poor germination associated with physical dormancy was experienced in the legume Aeschynomene histrix Poir. seeds and can reduce the establishment and growth of this species. Objectives. To evaluate the effects of different pre-planting treatments, including digestion by Lagune cattle or other preplanting treatments on the germinability of A. histrix seeds. Method. The experiment was divided into three phases. Firstly, six Lagune cattle (three young bulls and three heifers) were fed individually with 1,000 seeds and these seeds were subsequently collected from faeces. Secondly, seed germination was compared among seeds defecated by cattle and seeds submitted to seven other pre-planting treatments: control (intact untreated seeds); seeds scarified using sandpaper; and seeds immersed in 80 °C-hot water for 2, 4, 6, 8, and 10 min. Thirdly, we also assessed the effect of crumbling cattle faeces on A. histrix germinability. Results. The results show that Lagune cattle can disperse seeds of A. histrix with maximum recovery on the second day after ingestion. Of the number of seeds fed 13.42% were recovered. The germination percentage was greatest for sandpaper scarified seeds (96%) and seeds pre-heated during 2 min (86%), but least for digested seeds (4.27%). Breaking-down the dung doubled seedling emergence from digested seeds. Conclusions. As it is desirable to break dormancy of A. histrix seeds, the use of mechanical scarification using sandpapering or hot water scarification 80 °C at 2 min may be more beneficial than cattle digestion.

scholarly journals Markedly different patterns of imbibition in seeds of 48 Acacia species

2019 ◽  
Vol 29 (4) ◽  
pp. 270-282 ◽  
Author(s):  
Geoffrey E. Burrows ◽  
Rowan Alden ◽  
Wayne A. Robinson
Keyword(s):  
Process Control ◽  
Seed Coat ◽  
Germination Percentage ◽  
Rain Gauge ◽  
Hot Water ◽  
Physical Dormancy ◽  
Acacia Species ◽  
Rain Events

AbstractThe seeds of most Australian acacias have pronounced physical dormancy (PY). While fire and hot water (HW) treatments cause the lens to ‘pop’ almost instantaneously, for many Acacia species the increase in germination percentage can be gradual. If PY is broken instantly by HW treatment, why is germination often an extended process? Control and HW treatments were performed on seeds of 48 species of Acacia. Seeds were placed on a moist substrate and imbibition was assessed by frequently weighing individual seeds. In the two soft-seeded species all control seeds were fully imbibed within 6–24 h, while in hard-seeded species very few control seeds imbibed over several weeks. In 10 species over 50% of the HW-treated seeds imbibed within 30 h, but mostly the percentage of imbibed seeds gradually increased over several weeks. Some seeds in a replicate would imbibe early, while others would remain unimbibed for many days or weeks then, remarkably, become fully imbibed in less than 24 h. While HW treatment broke PY almost instantaneously, it appeared that in many Acacia species some other part of the testa slowed water from reaching the embryo. This process of having staggered imbibition may be a way of ensuring not all seeds in a population germinate after small rain events. Thus it appears the lens acts as a ‘fire gauge’ while some other part of the seed coat acts as a ‘rain gauge’.

scholarly journals Influence of Seed Size, Testa Color, Scarification Method, and Immersion in Cool or Hot Water on Germination of Baptisia australis (L.) R. Br. Seeds

HortScience ◽  
2005 ◽  
Vol 40 (6) ◽  
pp. 1846-1849 ◽  
Author(s):  
Thomas H. Boyle ◽  
Kristen Hladun
Keyword(s):  
Temporal Variation ◽  
Seed Size ◽  
Immersion Time ◽  
Germination Percentage ◽  
Hot Water ◽  
Physical Dormancy ◽  
Immersion Period ◽  
Series Of Experiments ◽  
Testa Color ◽  
Seeds Germination

A series of experiments was performed to examine the germination responses of Baptisia australis (L.) R. Br. seeds. Germination tests were conducted at 23 °C and numbers of germinated seed were counted daily for 21 days. Seeds were separated into two size fractions using standard sieves. Seeds in the large-seeded fraction were heavier than those in the small-seeded fraction, but seed size/weight did not affect the germination percentage at 21 days (G21), the number of days to 50% of final germination (T50), or the number of days between 10% and 90% germination (T90 – T10). Seeds were classified into two groups based on testa color. Light-brown seeds (17% of total) were heavier and had lower G21 and higher T50 and T90 – T10 values than medium- to dark-brown seeds (83% of total). Seeds scarified mechanically germinated nearly 100% and had lower T50 and T90 – T10 values than untreated seeds. Untreated seeds had a higher T50 value than seeds soaked overnight in 20°C water, but the G21 and T90-T10 values were similar for the two treatments. Mechanical scarification followed by overnight soaking in 20 °C water yielded a G21 value of only 12%, and the low germination percentage was attributed to imbibition damage. When seeds were scarified in concentrated H2SO4 for 0, 1, 5, 20, 40, or 80 min, G21 values increased quadratically while T50 and T90 – T10 values decreased quadratically as the immersion time increased. To test the effects of moist heat on germination responses, seeds were immersed for 0, 0.5, 1, 2, 4, or 8 minutes in 85 °C water. G21 values increased linearly as the immersion period increased from 0 to 2 min but remained similar when the immersion time exceeded 2 min. The duration of immersion in hot water did not affect the T50 values whereas T90 – T10 values decreased linearly as the immersion period increased. We conclude that physical dormancy is responsible for temporal variation in germination of B. australis seeds. Scarifying seed in concentrated H2SO4 for 20 to 80 minutes may be the most practical means of treating bulk lots of B. australis seeds to obtain rapid and uniform (≥85%) germination.

scholarly journals Overcoming dormancy in seeds of Dietes bicolor (Steud.) Sweet ex Klatt

2022 ◽  
Vol 28 (1) ◽  
pp. 60-66
Author(s):  
Thiago Roberto Rezende Borges ◽  
Maurecilne Lemes da Silva ◽  
Givanildo Zildo da Silva ◽  
Diego Ismael Rocha
Keyword(s):  
Block Design ◽  
Relevant Information ◽  
Germination Percentage ◽  
Hot Water ◽  
Combined Treatments ◽  
Physical Dormancy ◽  
Morphophysiological Dormancy ◽  
Randomized Block Design ◽  
Dunnett's Test ◽  
Ornamental Species

Abstract Seminiferous propagation of Dietes bicolor is hindered by the probable physical and/or morphophysiological dormancy. The objective was to analyze the efficacy of different methods of overcoming dormancy in D. bicolor seeds to determine a possible pre-germination treatment for the species. Two experiments were conducted: (I) Evaluation of the breaking of physical dormancy, in which the treatments of mechanical scarification were carried using sandpaper #100; chemical scarification with sulfuric acid (H2SO4) for 5 and 10 minutes and immersion in hot water (70 ºC), also, for 5 and 10 minutes, were evaluated. The intact seed was considered a control. (II) Evaluation of morphophysiological dormancy, in which the seeds were submitted to combined treatments of stratification of hot temperature (20-35 °C) and/or cold temperature (9 ºC), distributed in periods of 0, 1, and 2 weeks, totalizing 9 treatments. In both experiments, germination percentage (G), germination speed index (GSI), and first count (FC) were determined, using a randomized block design, and evaluated by the Scott-Knott test at 1% and Dunnett’s test at 5%. The use of H2SO4 10 minutes induced 42% germination, 0.52 GSI, and 18% FC, but only FC was significantly different from the control. In the second trial, the treatment that spent only two weeks in hot temperatures (20-35 ºC) showed the highest germination (30%), compared to the control (G = 22%). These results provide relevant information for understanding the physiology of D. bicolor germination, in addition to contributing to the optimization of pre-germination practices for this important ornamental species.

scholarly journals A field perspective on effects of fire and temperature fluctuation on Cerrado legume seeds

2017 ◽  
Vol 27 (2) ◽  
pp. 74-83 ◽  
Author(s):  
L. Felipe Daibes ◽  
Talita Zupo ◽  
Fernando A.O. Silveira ◽  
Alessandra Fidelis
Keyword(s):  
Temperature Fluctuation ◽  
Field Experiments ◽  
Seed Viability ◽  
Soil Surface ◽  
Temperature Fluctuations ◽  
Fire Effects ◽  
Fuel Load ◽  
Physical Dormancy ◽  
Legume Seeds ◽  
Field Perspective

AbstractInformation from a field perspective on temperature thresholds related to physical dormancy (PY) alleviation and seed resistance to high temperatures of fire is crucial to disentangle fire- and non-fire-related germination cues. We investigated seed germination and survival of four leguminous species from a frequently burned open Neotropical savanna in Central Brazil. Three field experiments were conducted according to seed location in/on the soil: (1) fire effects on exposed seeds; (2) fire effects on buried seeds; and (3) effects of temperature fluctuations on exposed seeds in gaps and shaded microsites in vegetation. After field treatments, seeds were tested for germination in the laboratory, together with the control (non-treated seeds). Fire effects on exposed seeds decreased viability in all species. However, germination of buried Mimosa leiocephala seeds was enhanced by fire in an increased fuel load treatment, in which we doubled the amount of above-ground biomass. Germination of two species (M. leiocephala and Harpalyce brasiliana) was enhanced with temperature fluctuation in gaps, but this condition also decreased seed viability. Our main conclusions are: (1) most seeds died when exposed directly to fire; (2) PY could be alleviated during hotter fires when seeds were buried in the soil; and (3) daily temperature fluctuations in gaps also broke PY of seeds on the soil surface, so many seeds could be recruited or die before being incorporated into the soil seed banks. Thus seed dormancy-break and germination of legumes from Cerrado open savannas seem to be driven by both fire and temperature fluctuations.

Biocement: Green Building- and Energy-Saving Material

2011 ◽  
Vol 347-353 ◽  
pp. 4051-4054 ◽  
Author(s):  
Jian Chu ◽  
Volodymyr Ivanov ◽  
Viktor Stabnikov ◽  
Jia He ◽  
Bing Li ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Microbial Biomass ◽  
Enzymatic Activity ◽  
Energy Saving ◽  
Building Material ◽  
Clayey Soil ◽  
Raw Materials ◽  
Green Building ◽  
Specific Enzymatic Activity ◽  
Porous Soil

Cement and chemical grouts have often been used for soil strengthening. However, high cost, energy consumption, and harm to environment restrict their applications. Biocement could be a new green building- material and energy-saving material. Biocement is a mixture of enzymes or microbial biomass with inorganic chemicals, which can be produced from cheap raw materials. Supply of biocementing solution to the porous soil or mixing of dry biocement with clayey soil initiate biocementation of soil due to specific enzymatic activity. Different microorganisms and enzymes can be used for production of biocement.

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.

scholarly journals Susceptibility of Some Sugarcane Varieties to the Heat Treatment Used in the Control of Chlorotic Streak

1969 ◽  
Vol 40 (1) ◽  
pp. 67-69
Author(s):  
José Adsuar
Keyword(s):  
Heat Treatment ◽  
Puerto Rico ◽  
Water Treatment ◽  
Virus Disease ◽  
Germination Percentage ◽  
Hot Water ◽  
Hot Water Treatment ◽  
Agricultural Experiment Station ◽  
Sugarcane Varieties ◽  
Agricultural Experiment

Chlorotic streak, a virus disease of sugarcane, is known to occur in Puerto Rico and to cause a reduction in germination, tillering, and yield of sugarcane per acre. Immersion of the infected cane in hot water at 52° C. for 20 minutes inactivated the virus and increased the yield of cane and sugar. It is also known that the hot-water treatment may adversely affect the germination of the different varieties. Thirteen of the best sugarcane varieties as recommended by this Agricultural Experiment Station were tested for susceptibility to the hot-water treatment. The treatment adversely affected the germination percentage of M. 336, B. 41227, and Co. 281. It stimulated the germination of varieties H. 328560, P.R. 1000, B. 37161, B. 40105, B. 37172, B. 371933, P.R. 907, and P.R. 902. It had no significant effect on the germination of P.R. 905 and P.R. 980.

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