scholarly journals Diurnal photoperiods and rhythmicity of the phototropic bending response in hypocotyls of sunflower, Helianthus annuus L. seedlings

2021 ◽  
pp. 18-18
Author(s):  
Dragan Vinterhalter ◽  
Branka Vinterhalter
Keyword(s):  
Helianthus Annuus ◽  
Lag Phase ◽  
Phase Duration ◽  
Helianthus Annuus L ◽  
Prolonged Duration ◽  
Bending Capacity ◽  
Daily Rhythmicity ◽  
Free Running ◽  
Bending Response ◽  
Diurnal Rhythmicity

Research on phototropic (PT) bending in sunflower (Helianthus annuus L. cv. Kondi (Syngenta)) seedling hypocotyls presented herein focused on a comparison of diurnal and free-running photoperiods with the aim of explaining the development of diurnal rhythmicity. PT bending magnitudes and lag phase duration exhibited strong daily rhythmicity in all diurnal photoperiods, contrasting with the uniform PT bending response to constant light (CL) conditions. Plants had a daytime maximum for PT bending magnitudes in experiments starting around midday and a minimum in the dark period in those starting 4 h after dusk. Plants could compensate for large differences in the daytime duration of diurnal photoperiods. They required the first 4 h of darkness to recover and synchronize the PT bending and to start increasing the magnitudes of PT bending. The daily pattern of lag phase duration changes was similar but inverted, showing that synchronization also occurred during nighttime. Darkness was not required for PT bending under CL conditions, however, during diurnal photoperiods it enabled the establishment of diurnal rhythmicity and synchronized changes in PT bending capacity to occur when needed, providing maximal values at midday and minimal during the nighttime. Under prolonged duration of daytime corresponding to the start of CL condition, plantlets rapidly abandoned circadian regulation, their PT bending response becoming arrhythmic.

THE PROBLEM OF SAFE SUNFLOWER (Helianthus annuus L.) USE FOR FOOD AND FODDER PURPOSES (review)

2018 ◽  
Vol 53 (3) ◽  
pp. 485-498
Author(s):  
G.P. Kononenko ◽  
◽  
M.I. Ustyuzhanina ◽  
A.A. Burkin ◽  
◽  
...  
Keyword(s):  
Helianthus Annuus ◽  
Helianthus Annuus L

Sunflowers (Helianthus annuus L.) on Top of a Constructed Wetland as an Engineered Ecosystem to Clean Sewage Onsite

2014 ◽  
Vol 2014 (2) ◽  
pp. 83-91
Author(s):  
Alfredo Garcia-Perez ◽  
◽  
Mark Harrison ◽  
Bill Grant ◽  
◽  
...  
Keyword(s):  
Helianthus Annuus ◽  
Constructed Wetland ◽  
Helianthus Annuus L

scholarly journals Reciprocal hemizygosity analysis reveals that the Saccharomyces cerevisiae CGI121 gene affects lag time duration in synthetic grape must

2021 ◽  
Author(s):  
Runze Li ◽  
Rebecca C Deed
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Low Temperatures ◽  
Lag Time ◽  
Lag Phase ◽  
Phenotypic Traits ◽  
Time Duration ◽  
Phase Duration ◽  
Grape Must ◽  
The Impact ◽  
Reciprocal Hemizygosity Analysis

Abstract It is standard practice to ferment white wines at low temperatures (10-18 °C). However, low temperatures increase fermentation duration and risk of problem ferments, leading to significant costs. The lag duration at fermentation initiation is heavily impacted by temperature; therefore, identification of Saccharomyces cerevisiae genes influencing fermentation kinetics is of interest for winemaking. We selected 28 S. cerevisiae BY4743 single deletants, from a prior list of open reading frames (ORFs) mapped to quantitative trait loci (QTLs) on chromosomes VII and XIII, influencing the duration of fermentative lag time. Five BY4743 deletants, Δapt1, Δcgi121, Δclb6, Δrps17a, and Δvma21, differed significantly in their fermentative lag duration compared to BY4743 in synthetic grape must (SGM) at 15 °C, over 72 h. Fermentation at 12.5 °C for 528 h confirmed the longer lag times of BY4743 Δcgi121, Δrps17a, and Δvma21. These three candidate ORFs were deleted in S. cerevisiae RM11-1a and S288C to perform single reciprocal hemizygosity analysis (RHA). RHA hybrids and single deletants of RM11-1a and S288C were fermented at 12.5 °C in SGM and lag time measurements confirmed that the S288C allele of CGI121 on chromosome XIII, encoding a component of the EKC/KEOPS complex, increased fermentative lag phase duration. Nucleotide sequences of RM11-1a and S288C CGI121 alleles differed by only one synonymous nucleotide, suggesting that intron splicing, codon bias, or positional effects might be responsible for the impact on lag phase duration. This research demonstrates a new role of CGI121 and highlights the applicability of QTL analysis for investigating complex phenotypic traits in yeast.

scholarly journals Predictive Modeling for the Growth of Salmonella spp. in Liquid Egg White and Application of Scenario-Based Risk Estimation

2021 ◽  
Vol 9 (3) ◽  
pp. 486
Author(s):  
Mi Seon Kang ◽  
Jin Hwa Park ◽  
Hyun Jung Kim
Keyword(s):  
Predictive Model ◽  
Scenario Analysis ◽  
Specific Growth ◽  
Risk Estimation ◽  
Egg White ◽  
Lag Phase ◽  
Salmonella Spp ◽  
Baseline Model ◽  
Phase Duration ◽  
Root Model

The objective of the study was to develop a predictive model of Salmonella spp. growth in pasteurized liquid egg white (LEW) and to estimate the salmonellosis risk using the baseline model and scenario analysis. Samples were inoculated with six strains of Salmonella, and bacterial growth was observed during storage at 10–37 °C. The primary models were developed using the Baranyi model for LEW. For the secondary models, the obtained specific growth rate (μmax) and lag phase duration were fitted to a square root model and Davey model, respectively, as functions of temperature (R2 ≥ 0.98). For μmax, the values were satisfied within an acceptable range (Af, Bf: 0.70–1.15). The probability of infection (Pinf) due to the consumption of LEW was zero in the baseline model. However, scenario analysis suggested possible salmonellosis for the consumption of LEW. Because Salmonella spp. proliferated much faster in LEW than in egg white (EW) during storage at 20 and 30 °C (p < 0.01), greater Pinf may be obtained for LEW when these products are stored at the same conditions. The developed predictive model can be applied to the risk management of Salmonella spp. along the food chain, including during product storage and distribution.

scholarly journals TEMPERATURE - GERMINATION RESPONSES OF SUNFLOWER (Helianthus annuus L.) GENOTYPES / GERMINACION COMO REACCION A LA TEMPERATURA EN LOS GENOTIPOS DEL GIRASOL (Helianthus annuus L.) / GERMINATION - RÉACTION À LA TEMPÉRATURE DANS LES GÉNOTYPES DE TOURNESOL (Helianthus annuus L.)

Helia ◽  
2000 ◽  
Vol 23 (33) ◽  
pp. 97-104
Author(s):  
F.M. Khalifa ◽  
A.A. Schneiter ◽  
E.I. El Tayeb
Keyword(s):  
Seed Germination ◽  
Helianthus Annuus ◽  
Maximum Rate ◽  
Germination Rate ◽  
Thermal Time ◽  
Large Temperature ◽  
Climatic Zones ◽  
Helianthus Annuus L ◽  
Wide Range ◽  
Cardinal Temperature

SUMMARY Seed germination of six sunflower (Helianthus annuus L.) hybrids was investigated across a range of eleven constant temperatures between 5°C and 45°C. Large temperature differences in germination rate 1/t (d-1), cardinal temperature (°C) and thermal time θ (°cd) were observed among hybrids. Base temperatures (Tb) varied between 3.3°C and 6.7°C whereas maximum germination temperatures (Tm) varied between 41.7°C and 48.9°C. Final germination fraction was attained at 15°C - 25°C whereas the maximum rate of germination was attained at 30.4°C - 35.6°C. The maximum germination rate of hybrid USDA 894, the cultivar with the slowest germination rate, was only 50% of that of hybrid EX 47. The low Tb and high Tm of sunflower appear to be one of the factors which explain the successful adaptation of sunflower to a wide range of temperature. These findings are discussed in relation to the origin of the crop and its wide adaptations in diverse habitats and climatic zones.

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