scholarly journals Seed dormancy as an obstacle ın front of plant production

2018 ◽  
Vol 1 (3) ◽  
Author(s):  
Mustafa YILDIZ
Keyword(s):  
High Frequency ◽  
Seed Tuber ◽  
Plant Production ◽  
Hard Seed ◽  
Field Crops ◽  
Physiological Dormancy ◽  
Activity Of Enzymes ◽  
Chemical Pretreatments ◽  
Physical And Chemical ◽  
Hard Seed Coat

Dormancy is a state of lack of germination/sprouting in seed/tuber although required conditions (temperature, humidity, oxygen and light) are provided. Dormancy is based on hard seed coat dormancy or lack of supply and activity of enzymes (internal dormancy) necessary for germination/sprouting. Dormancy is an important factor limiting production in many field crops. Several physical and chemical pretreatments to production material (seed/tuber) are carried out for overcoming dormancy. Physical and physiological dormancy can be found together in some plants and this event makes difficult to provide high frequency healthy seedling growth. Whereas, emerging of all production material (seed, tuber) sown/planted and forming healthy seedling is a prerequisite of plant production.

Dormancy breakage in Cercis chinensis seeds

2020 ◽  
Vol 100 (6) ◽  
pp. 666-673
Author(s):  
Yunpeng Gao ◽  
Mingwei Zhu ◽  
Qiuyue Ma ◽  
Shuxian Li
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Seed Coat ◽  
Germination Percentage ◽  
Physical Dormancy ◽  
Optimal Method ◽  
Hard Seed ◽  
Positive Effects ◽  
Physiological Dormancy ◽  
Hard Seed Coat

The seeds of Cercis chinensis Bunge are important for reproduction and propagation, but strong dormancy controls their germination. To elucidate the causes of seed dormancy in C. chinensis, we investigated the permeability of the hard seed coat and the contribution of the endosperm to physical dormancy, and we examined the effect of extracts from the seed coat and endosperm. In addition, the effectiveness of scarification methods to break seed dormancy was compared. Cercis chinensis seeds exhibited physical and physiological dormancy. The hard seed coat played an important role in limiting water uptake, and the endosperm acted as a physical barrier that restricted embryo development in imbibed seeds. Germination percentage of Chinese cabbage [Brassica rapa subsp. chinensis (L.) Hanelt] seeds was reduced from 98% (control) to 28.3% and 56.7% with a seed-coat extract and an endosperm extract, respectively. This demonstrated that both the seed coat and endosperm contained endogenous inhibitors, but the seed-coat extract resulted in stronger inhibition. Mechanical scarification, thermal scarification, and chemical scarification had positive effects on C. chinensis seed germination. Soaking non-scarified seeds in gibberellic acid (GA3) solution did not promote germination; however, treatment with exogenous GA3 following scarification significantly improved germination. The optimal method for promoting C. chinensis seed germination was soaking scarified seeds in 500 mg·L−1 GA3 for 24 h followed by cold stratification at 5 °C for 2 mo.

scholarly journals Effect of the seed coat on dormancy and germination in Stylosanthes humilis H. B. K. Seeds

2017 ◽  
Vol 39 (2) ◽  
pp. 114-122 ◽  
Author(s):  
Izabel de Souza Chaves ◽  
Nilo Cesar Queiroga Silva ◽  
Dimas Mendes Ribeiro
Keyword(s):  
Seed Coat ◽  
Room Temperature ◽  
Low Ph ◽  
Physical Dormancy ◽  
Hard Seed ◽  
Stylosanthes Humilis ◽  
Physiological Dormancy ◽  
Radicle Protrusion ◽  
Townsville Stylo ◽  
Hard Seed Coat

Abstract: Seed of Townsville stylo (Stylosanthes humilis H.B.K.) is known to exhibit a hard seed coat and when freshly harvested also show a physiological dormancy, however, the nature of the co-actions between seed coat and embryo growth that determine dormancy is poorly understood. In this study, physical dormancy of Townsville stylo seeds was not reduced during natural ageing at room temperature, in contrast to the physiological dormancy, which is gradually overcome during after-ripening. Furthermore, the permeability of seed coat was affected by scarification treatments as well as by low-pH solutions. Together, these data indicate that physical dormancy overcome of seed is prerequisite for radicle protrusion and physiological dormancy of Townsville stylo seeds contribute to its timing.

Physical and chemical difference of seed coat between hard and soft seeds of Licorice (Glycyrrhiza Uralensis Fisch) 

2018 ◽  
Author(s):  
Qun Sun ◽  
Liwei Zhu ◽  
Wenjing Zhang and Jianhua Wang
Keyword(s):  
Seed Coat ◽  
Mineral Elements ◽  
Chemical Difference ◽  
X Ray ◽  
Hard Seed ◽  
Hard Seeds ◽  
Significant Enrichment ◽  
Physical Impact ◽  
Physical And Chemical ◽  
Hard Seed Coat

In this paper, the physical and chemical differences of seed coat between hard and soft seeds from the same Licorice lot were identified. Electron microscopy-based examination revealed that the cracks on hard seeds coat were much less obvious (shallower and narrower) than those of soft seeds, and that hilar fissure from hard seeds was considerably narrower. Endosperm of hard seeds was markedly thicker than that of soft seeds. Finally, X-ray fluorescence spectrometry revealed significant enrichment for 12 out of the 14 tested mineral elements in hard seed coat. It could be concluded that these above features of hard seeds would increase their resistance to physical impact and protect against cracks in seed coat surface, thus contributing to the impermeability of hard seeds.

LOW-TEMPERATURE ION-PLASMA DEPOSITION TECHNOLOGY OF NANOSTRUCTURED FILMS OF ALUMINUM AND BORON NITRIDES

2021 ◽  
Vol 56 ◽  
pp. 97-107
Author(s):  
M. S. Zayats ◽  
Keyword(s):  
Dielectric Properties ◽  
Low Temperature ◽  
Magnetron Sputtering ◽  
High Frequency ◽  
Plasma Deposition ◽  
Heating Temperature ◽  
Substrate Heating ◽  
Ion Plasma ◽  
Technological Cycle ◽  
Physical And Chemical

A low-temperature (substrate heating temperature up to 400 °C) ion-plasma technology for the formation of nanostructured AlN and BN films by the method of high-frequency reactive magnetron sputtering of the corresponding targets has been developed (the modernized installation "Cathode-1M"), which has in its technological cycle the means of physical and chemical modification, which allow to purposefully control the phase composition, surface morphology, size and texture of nanocrystalline films. The possibility of using the method of high-frequency magnetron sputtering for deposition of transparent hexagonal BN films in the nanoscale state on quartz and silicon substrates is shown. Atomic force microscopy (AFM) has shown that AlN films can have an amorphous or polycrystalline surface with grain sizes of approximately 20-100 nm, with the height of the nanoparticles varying from 3 to 10 nm and the degree of surface roughness from 1 to 10 nm. It was found that the dielectric penetration of polycrystalline AlN films decreases from 10 to 3.5 at increased frequencies from 25 Hz to 1 MHz, and the peak tangent of the dielectric loss angle reaches 0.2 at 10 kHz. Such features indicate the existence of spontaneous polarization of dipoles in the obtained AlN films. Interest in dielectric properties in AlN / Si structures it is also due to the fact that there are point defects, such as nitrogen vacancies and silicon atoms, which diffuse from the silicon substrate during synthesis and play an important role in the dielectric properties of AlN during the formation of dipoles. The technology makes it possible, in a single technological cycle, to produce multilayer structures modified for specific functional tasks with specified characteristics necessary for the manufacture of modern electronics, optoelectronics and sensorics devices. It should also be noted that the technology of magnetron sputtering (installation "Cathode-1M") is highly productive, energetically efficient and environmentally friendly in comparison with other known technologies for creating semiconductor structures and allows them to be obtained with minimal changes in the technological cycle.

scholarly journals Effect of pre-sowing treatments and growing media on seed germination and seedling growth of Albizia lebbeck (L.) Benth

2018 ◽  
Vol 10 (3) ◽  
pp. 860-863
Author(s):  
Naresh Kumar ◽  
A. K. Handa ◽  
Inder Dev ◽  
Asha Ram ◽  
A. R. Uthappa ◽  
...  
Keyword(s):  
Seedling Growth ◽  
Room Temperature ◽  
Cold Water ◽  
Hot Water ◽  
Albizia Lebbeck ◽  
Physical Dormancy ◽  
Growing Media ◽  
Hard Seed ◽  
Collar Diameter ◽  
Hard Seed Coat

The seeds of Albizia lebbeck have been observed to exhibit physical dormancy due to presence of hard seed-coat. To overcome this problem, the seeds were subjected to seven pre-sowing treatments viz., T1-immersion of seeds in cold water for 12 h; T2-immersion of seeds in cold water for 24 h; T3-immersion of seeds in hot water (100 °C) and subsequent cooling at room temperature for 12 h; T4-immersion of seeds in hot water (100 °C) and subsequent cooling at room temperature for 24 h; T5-immersion of seeds in cold water for 12 h followed by immersion in hot water (100 °C) and allowed to cool for 1 h; T6-immersion of seeds in cold water for 24 h followed by immersion in hot water (100 °C) and allowed to cool for 1 h. Untreated seeds served as control (T0). Treatment T3 gave highest germination (96%) which was comparable with T5 (95 %), T4 (94 %) and T6 (93%). Nine growing media viz., T1: soil,  T2: soil+sand (2:1), T3: soil+perlite (2:1), T4: soil+Farm Yard Manure (FYM) (2:1), T5: soil+vermicompost (2:1), T6: soil+sand+FYM (1:1:1), T7: soil+sand+vermicompost (1:1:1), T8: soil+perlite+FYM (1:1:1) and T9: soil+perlite+ vermicompost (1:1:1) were, also, studied for their effect on seedling growth of A. lebbeck. Among these media, maximum values of shoot length (23.82 cm), root length (21.14 cm), collar diameter (3.59 mm) and seedling quality index (0.350) were observed in T7.

Effectiveness of Physical and Chemical Pretreatments in Enhancing Cotton Gin Trash In Vitro Ruminant Digestibility

2002 ◽  
Author(s):  
Samuel J. Ray ◽  
Lester O. Pordesimo ◽  
Michael J. Buschermohle ◽  
John C. Waller ◽  
John B. Wilkerson
Keyword(s):  
Chemical Pretreatments ◽  
Physical And Chemical ◽  
Cotton Gin

II. An Experiment in Marine Fish Cultivation: II. Some Physical and Chemical Conditions in a Fertilized Sea-loch (Loch Craiglin, Argyll)

1947 ◽  
Vol 63 (1) ◽  
pp. 3-20 ◽  
Author(s):  
A. P. Orr
Keyword(s):  
Marine Fish ◽  
Sea Water ◽  
Animal Production ◽  
Plant Production ◽  
Natural Conditions ◽  
Chemical Conditions ◽  
Physical And Chemical

The dependence of plant production in the sea on the presence of nutrient salts, especially nitrate and phosphate, and on illumination has been repeatedly demonstrated. The object of the present work was to find primarily whether, and to what degree, plant and animal production could be increased by adding fertilizers to an enclosed body of sea water under otherwise natural conditions.

Influence of electromagnetic treatment of fillers on physical and chemical properties of the adhesive compositions for plywood manufacture

10.12737/4518 ◽  
2014 ◽  
Vol 4 (2) ◽  
pp. 135-144
Author(s):  
Бельчинская ◽  
Larisa Belchinskaya ◽  
Анисимов ◽  
Maksim Anisimov ◽  
Попов ◽  
...  
Keyword(s):  
High Frequency ◽  
Chemical Properties ◽  
Adhesive Layer ◽  
Internal Stresses ◽  
Pulsed Magnetic Fields ◽  
Electromagnetic Treatment ◽  
Adhesive Compositions ◽  
Reduction Of Emissions ◽  
Physical And Chemical ◽  
And Chemical Properties

During this work the reduction of emissions of free formaldehyde of the cured adhesive composition for the manufacture of environmentally friendly plywood is identified, through the introduction of pre-activated sorbent of fillers into its composition, as well as reducing internal stresses in the adhesive layer of the cured binder. The resulting effects are related with the use of adhesive formulations of different sorbents fillers subjected to preactivation in various electromagnetic fields (fields over high frequency and weak pulsed magnetic fields).

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