scholarly journals A Reliable Methodology for Determining Seed Viability by Using Hyperspectral Data from Two Sides of Wheat Seeds

Sensors ◽  
2018 ◽  
Vol 18 (3) ◽  
pp. 813 ◽  
Author(s):  
Tingting Zhang ◽  
Wensong Wei ◽  
Bin Zhao ◽  
Ranran Wang ◽  
Mingliu Li ◽  
...  
Keyword(s):  
Seed Viability ◽  
Hyperspectral Data ◽  
Two Sides ◽  
Wheat Seeds

scholarly journals Comparative Proteomics at the Critical Node of Vigor Loss in Wheat Seeds Differing in Storability

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiuling Chen ◽  
Andreas Börner ◽  
Xia Xin ◽  
Manuela Nagel ◽  
Juanjuan He ◽  
...  
Keyword(s):  
Seed Viability ◽  
Storage Period ◽  
Protein Translation ◽  
Artificial Ageing ◽  
Plateau Phase ◽  
Cell Defense ◽  
Critical Node ◽  
Cytotoxic Compounds ◽  
Wheat Seeds

The critical node (CN, 85% germination) of seed viability is an important threshold for seed regeneration decisions after long-term conservation. Dependent on the germplasm, the storage period until CN is reached varies and information on the divergence of the proteomic profiles is limited. Therefore, the study aims to identify key proteins and mechanisms relevant for a long plateau phase and a late CN during artificial seed aging of wheat. Seeds of the storage-tolerant genotype (ST) TRI 23248, and the storage-sensitive genotype (SS) TRI 10230 were exposed to artificial ageing (AA) and extracted embryos of imbibed seeds were analyzed using an iTRAQ-based proteomic technique. ST and SS required AA for 24 and 18 days to reach the CN, respectively. Fifty-seven and 165 differentially abundant proteins (DAPs) were observed in the control and aged groups, respectively. Interestingly, a higher activity in metabolic processes, protein synthesis, transcription, cell growth/division, and signal transduction were already found in imbibed embryos of control ST seeds. After AA, 132 and 64 DAPs were accumulated in imbibed embryos of both aged ST and SS seeds, respectively, which were mainly associated with cell defense, rescue, and metabolism. Moreover, 78 DAPs of ST appeared before CN and were mainly enriched in biological pathways related to the maintenance of redox and carbon homeostasis and they presented a stronger protein translation ability. In contrast, in SS, only 3 DAPs appeared before CN and were enriched only in the structural constituents of the cytoskeleton. In conclusion, a longer span of plateau phase might be obtained in seeds when proteins indicate an intense stress response before CN and include the effective maintenance of cellular homeostasis, and avoidance of excess accumulation of cytotoxic compounds. Although key proteins, inherent factors and the precise regulatory mechanisms need to be further investigated, the found proteins may also have functional potential roles during long-term seed conservation.

scholarly journals Tetrazolium test adjustment for wheat seeds

2013 ◽  
Vol 35 (3) ◽  
pp. 361-367 ◽  
Author(s):  
Tereza Cristina de Carvalho ◽  
Francisco Carlos Krzyzanowski ◽  
Osvaldo de Castro Ohlson ◽  
Maristela Panobianco
Keyword(s):  
Seed Viability ◽  
Longitudinal Section ◽  
Wheat Seed ◽  
Germination Test ◽  
Efficient Procedure ◽  
Paper Towels ◽  
Direct Immersion ◽  
Tetrazolium Test ◽  
Wheat Seeds ◽  
Test Adjustment

The assessment of the germination test in wheat seeds varies from 4 to 15 days, because the species normally presents dormancy in freshly harvested seeds. The tetrazolium test can characterize seed viability in less than 24 hours including lots with dormancy seeds. The objective of this study was to develop a practical and efficient procedure for evaluating the viability of wheat seeds using the tetrazolium test. Five seed lots of the BRS 208 cultivar were used, where the following were tested: a) pre-conditioning between moist paper towels or direct immersion in water for 18 hours, at 20 °C; b) longitudinal section of the embryo and the endosperm; c) coloration on paper or by immersion for 2 and 3 hours, at 30 and 40 °C; and d) concentrations of tetrazolium solution at 0.075%, 0.1%, 0.5% and 1.0%. The tetrazolium test may be efficiently used to evaluate wheat seed viability by pre-conditioning the seeds between paper towels (18 hours, at 20 °C) and adopting the following combinations of preparation and coloration: coloration of both halves of the seed on paper (2 hours, at 30 °C), in a 1.0% tetrazolium solution; or coloration of one half of the seed by immersion (3 hours, at 30 °C), in a 0.1% tetrazolium solution; or coloration of one half of the seed by immersion (2 hours, at 40 °C), in a 0.075% tetrazolium solution. This latter procedure is recommended for identifying and discarding lots with lower viability.

scholarly journals Study on prevalence of mycoflora on seeds of spring wheat in the conditions of the Samara region

2021 ◽  
pp. 25-29
Author(s):  
Marina Nikolaevna Kincharova ◽  
Alexander Ivanovich Kincharov
Keyword(s):  
Relative Abundance ◽  
Root Rot ◽  
Seed Viability ◽  
Percentage Frequency ◽  
Spring Soft Wheat ◽  
Alternaria Sp ◽  
Fusarium Sp ◽  
High Degree ◽  
Wheat Seeds ◽  
Variety Testing

Wheat seeds are a favorable environment for pathogenic mycoflora, which in turn causes a decrease in seed viability and the release of various mycotoxins that significantly affect the growth and development of plants. The study of the phytosanitary condition of spring soft wheat seed material of competitive variety testing for the seed borne pathogen was carried out. As a result of research, a high degree of infection of seeds with pathogens of root rot and mold on a natural infectious background was revealed. The studied seed samples were dominated by fungi: Alternaria sp. (with a percentage frequency from 3 to 23% in favorable years and 36-53% in unfavorable years, and a relative abundance of 7.9-54.8% and 48-69. 2%, respectively), Fusarium sp. (with a percentage frequency from 8 to 26% in favorable years and 1-19% in unfavorable years, and a relative abundance of 17.9-61.9% and 8-33. 3%, respectively) and a group of fungi that cause seed mold. Differences in precipitation and relative humidity may be a possible reason for differences in the frequency of occurrence and in the form of fungi found on wheat seeds in different years.

scholarly journals Water potential and time of Pyrenophora tritici-repentis inoculation in wheat seeds

2017 ◽  
Vol 38 (4) ◽  
pp. 1681 ◽  
Author(s):  
Victória Vieira Bertagnolli ◽  
Carolina Cardoso Deuner ◽  
Patrícia Frizon ◽  
Valéria Cecília Ghissi
Keyword(s):  
Water Potential ◽  
Mycelial Growth ◽  
Culture Medium ◽  
Seedling Emergence ◽  
Seed Viability ◽  
Growth Index ◽  
Tan Spot ◽  
Pyrenophora Tritici Repentis ◽  
Inoculation Time ◽  
Wheat Seeds

Wheat seeds infected with Pyrenophora tritici-repentis, the causal agent of tan spot, are partially responsible for outbreaks caused by this pathogen. Seed lots with a high incidence of P. tritici-repentis must be rapidly acquired for transmission and pathogen-control studies. Therefore, the aim of this study was to determine whether changes in water potential of culture medium and variations in inoculation time might favor the infection of wheat seeds by P. tritici-repentis without compromising seed viability. Colonies of P. tritici-repentis were grown on potato-dextrose-agar (PDA) culture medium, adjusted to a water potential of -0.36 MPa, under water stress induced by mannitol at potentials of -0.4, -0.6, -0.8, -1.0, and -1.2 MPa. Analyses were carried out to determine mycelial growth index and seed exposure time to the culture medium to start germination as a function of water potential. Afterwards, wheat seeds were placed in contact with colonies of P. tritici-repentis for 24, 48, and 72 hours at potentials of -0.4, -0.6, -0.8, -1.0, and -1.2 MPa. The experiment was arranged in a completely randomized design, in a factorial scheme (water potential × inoculation time). Rates of germination, seedling emergence in soil, and seed infection were assessed. Mycelial growth was stimulated at lower water potentials, which germinated faster. A 24-hour inoculation time and a -0.4 MPa water potential were efficient to infect wheat seeds with P. tritici-repentis, without hindering seedling germination and emergence under laboratory conditions.

Characterization of defects in tabular silver halide grains

1990 ◽  
Vol 48 (4) ◽  
pp. 1046-1047
Author(s):  
C. Goessens ◽  
D. Schryvers ◽  
J. Van Landuyt ◽  
A. Verbeeck ◽  
R. De Keyzer
Keyword(s):  
Radiation Damage ◽  
Silver Halide ◽  
Chemical Characteristics ◽  
X Ray ◽  
Free Region ◽  
Central Defect ◽  
Crystallographic Defects ◽  
Physical And Chemical ◽  
Two Sides

Silver halide grains (AgX, X=Cl,Br,I) are commonly recognized as important entities in photographic applications. Depending on the preparation specifications one can grow cubic, octahedral, tabular a.o. morphologies, each with its own physical and chemical characteristics. In the present study crystallographic defects introduced by the mixing of 5-20% iodide in a growing AgBr tabular grain are investigated. X-ray diffractometry reveals the existence of a homogeneous Ag(Br1-xIx) region, expected to be formed around the AgBr kernel. In fig. 1 a two-beam BF image, taken at T≈100 K to diminish radiation damage, of a triangular tabular grain is presented, clearly showing defect contrast fringes along four of the six directions; the remaining two sides show similar contrast under relevant diffraction conditions. The width of the central defect free region corresponds with the pure AgBr kernel grown before the mixing with I. The thickness of a given grain lies between 0.15 and 0.3 μm: as indicated in fig. 2 triangular (resp. hexagonal) grains exhibit an uneven (resp. even) number of twin interfaces (i.e., between + and - twin variants) parallel with the (111) surfaces. The thickness of the grains and the existence of the twin variants was confirmed from CTEM images of perpendicular cuts.

The Eleventh Circuit Holds that Agreements in which Pharmaceutical Companies Pay Generic Companies Not to Compete May be Valid

2004 ◽  
Vol 32 (1) ◽  
pp. 181-184
Author(s):  
Amy Garrigues
Keyword(s):  
Pharmaceutical Companies ◽  
Court Decisions ◽  
Patent Holder ◽  
Trial Court ◽  
Court Of Appeals ◽  
The Us ◽  
Antitrust Laws ◽  
Per Se ◽  
Appeals Court ◽  
Two Sides

On September 15, 2003, the US. Court of Appeals for the Eleventh Circuit held that agreements between pharmaceutical and generic companies not to compete are not per se unlawful if these agreements do not expand the existing exclusionary right of a patent. The Valley DrugCo.v.Geneva Pharmaceuticals decision emphasizes that the nature of a patent gives the patent holder exclusive rights, and if an agreement merely confirms that exclusivity, then it is not per se unlawful. With this holding, the appeals court reversed the decision of the trial court, which held that agreements under which competitors are paid to stay out of the market are per se violations of the antitrust laws. An examination of the Valley Drugtrial and appeals court decisions sheds light on the two sides of an emerging legal debate concerning the validity of pay-not-to-compete agreements, and more broadly, on the appropriate balance between the seemingly competing interests of patent and antitrust laws.

The Two Sides of Temporal Orienting

2010 ◽  
Vol 57 (2) ◽  
pp. 142-148 ◽  
Author(s):  
Ángel Correa ◽  
Paola Cappucci ◽  
Anna C. Nobre ◽  
Juan Lupiáñez
Keyword(s):  
Executive Control ◽  
Stroop Effect ◽  
Traffic Situation ◽  
Target Onset ◽  
Stimulus Features ◽  
Two Sides ◽  
Spatial Stroop Effect ◽  
Probable Interval ◽  
Spatial Stroop ◽  
Temporal Orienting

Would it be helpful to inform a driver about when a conflicting traffic situation is going to occur? We tested whether temporal orienting of attention could enhance executive control to select among conflicting stimuli and responses. Temporal orienting was induced by presenting explicit cues predicting the most probable interval for target onset, which could be short (400 ms) or long (1,300 ms). Executive control was measured both by flanker and Simon tasks involving conflict between incompatible responses and by the spatial Stroop task involving conflict between perceptual stimulus features. The results showed that temporal orienting facilitated the resolution of perceptual conflict by reducing the spatial Stroop effect, whereas it interfered with the resolution of response conflict by increasing flanker and Simon effects. Such opposite effects suggest that temporal orienting of attention modulates executive control through dissociable mechanisms, depending on whether the competition between conflicting representations is located at perceptual or response levels.

Two sides of the same coin: Biculturalism and endorsement of cultural ideologies

2011 ◽  
Author(s):  
Stephanie A. Quezada ◽  
Isabel J. Gonzalez ◽  
Michael A. Zarate
Keyword(s):  
Cultural Ideologies ◽  
Two Sides
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