Changes in the ability of plants to alter the pH of the flooding medium as an early symptom of flooding stress in Helianthus annuus

1984 ◽  
Vol 62 (11) ◽  
pp. 2417-2422 ◽  
Author(s):  
David R. Drakeford ◽  
David M. Reid
Keyword(s):  
Helianthus Annuus ◽  
Nutrient Medium ◽  
Ph Value ◽  
Early Symptom ◽  
Hydroponic System ◽  
Flooding Stress ◽  
Helianthus Annuus L ◽  
Biophysical Changes ◽  
Passive Drift

Roots of sunflower plants (Helianthus annuus L.) were flooded in nutrient medium and nonflooded controls were continuously bathed with nutrient medium in a hydroponic system. The pH of the nutrient medium was measured over a period of days. Within 24 h the pH of the nutrient medium in the flooded treatments was 1 pH unit higher than that of the nonflooded treatments and remained higher over several days. Nonflooded plants were able to acidify the medium to a pH value of 4 but when flooded at this pH plants underwent a rapid "catastrophic death," different from normal senescence, in which the shoot dehydrated before chlorosis set in. This pH phenomenon is consistent with both an active acidification of the nutrient medium under nonstressed conditions and a passive drift to a pH dictated by the materials of the hydroponic system, under flooded conditions. It is postulated that flooding rapidly shuts down an acidification mechanism and that this may be symptomatic of early biophysical changes brought about by flooding.

Fates of ethanol produced during flooding of sunflower roots

1990 ◽  
Vol 68 (11) ◽  
pp. 2408-2414 ◽  
Author(s):  
G. A. U. Jayasekera ◽  
D. M. Reid ◽  
E. C. Yeung
Keyword(s):  
Organic Acids ◽  
Helianthus Annuus ◽  
Ethanol Metabolism ◽  
Steady Increase ◽  
Flooding Stress ◽  
Helianthus Annuus L ◽  
Initial Rise ◽  
Adh Activity ◽  
Organic Acids And Sugars ◽  
Ethanol Synthesis

Hypoxic flooding of sunflower (Helianthus annuus L. cv. Delgren 131) roots caused rapid promotion of ethanol synthesis. Some of the root-synthesized ethanol was retained while a major portion was leaked into the flooding medium. A portion of the root ethanol was transported to shoots via transpirational stream, where some of it was vented out to the air around the leaves. Sunflower roots and shoots have the capacity to utilize ethanol retained by incorporating the carbon from ethanol into lipids, amino and organic acids, and sugars. Removal of ethanol from tissues by leaking, by venting, and by metabolic reutilization may be useful mechanisms that sunflowers use to avoid ethanol accumulation. Shoots of flooded sunflower plants, which are of course important as sources of oxygen and carbohydrates for roots, also act as a sink for root ethanol. More ethanol metabolism may be taking place in shoots than in roots. Prolonged flooding stress caused a rapid and steady increase in ADH activity in roots, but ethanol levels showed a decline after an initial rise. ADH in flooded roots may be useful in the regeneration of NAD, thus ensuring continuation of glycolysis.

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 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.

scholarly journals RADIATION USE EFFICIENCY, ABOVE GROUND BIOMASS ACCUMULATION, CANOPY DEVELOPMENT, LEAF AREA-LIGHT INTERCEPTION PROFILES AND RADIATION INTERCEPTION OF SUNFLOWER (Helianthus annuus L.) AS INFLUENCED BY IRRIGATION REGIMEN / INFLUENCIA DEL RÉGIMEN DE IRRIGACIÓN SOBRE LA EFICACIA DEL USO DE LA RADIACIÓN, LA ACUMULACIÓN DE BIOMASA, EL DESAROROLLO DEL CANOPEO, EL ÁREA DE LA HOJA Y LOS PERFILES DE INTERCEPCIÓN DE LUZ Y DE RADIACIÓN EN GIRASOL (Helianthus annuus L.) / EFFICACITÉ DE L’UTILISATION DES RADIATIONS SOLAIRES, ACCUMULATION DE LA BIOMASSE DANS LA PARTIE AÉRIENNE, DÉVELOPPEMENT DE L’OMBRELLE, PROFILS D’INTERCEPTION DE LA LUMIÈRE PAR LA FEUILLE ET INTERCEPTION DES RADIATIONS SOLAIRES CHEZ LE TOURNESOL (Helianthus annuus L.) SOUS L’INFLUENCE D’UN RÉGIME D’IRRIGATION

Helia ◽  
2001 ◽  
Vol 24 (35) ◽  
pp. 101-110 ◽  
Author(s):  
S. Sridhara ◽  
T.G. Prasad
Keyword(s):  
Helianthus Annuus ◽  
Biomass Accumulation ◽  
Light Interception ◽  
Radiation Use Efficiency ◽  
Leaf Nitrogen Content ◽  
Radiation Interception ◽  
Canopy Development ◽  
Helianthus Annuus L ◽  
Use Efficiency ◽  
Radiation Use

SUMMARYA field experiment was conducted at Gandhi Krishi Vignana Kendra, University of Agricultural Sciences, Bangalore to study the effect of irrigation regimens on the biomass accumulation, canopy development, light interception and radiation use efficiency of sunflower. The treatments includes irrigating the plants at 0.4, 0.6, 0.8 and 1.0 cumulative pan evaporation. The results indicated that the aboveground biomass, canopy development, radiation interception and radiation use efficiency were influenced favorably by the irrigation regimens. Irrespective of the irrigation regimen, the radiation use efficiency of sunflower increased from 15 DAS to 75 DAS and then tended to decline. The decrease in RUE after anthesis is coupled with decrease in leaf nitrogen content. In general the RUE of sunflower ranged from 0.49 g MJ-1 to 1.84 g MJ-1 at different growth stages. The light transmission within the canopy increased exponentially with plant height and the canopy extension coefficient is found to be 0.8.

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