scholarly journals Effects of day length treatments on auxin content and its diurnal variation in soybean

1960 ◽  
Vol 29 (1) ◽  
pp. 163-166 ◽  
Author(s):  
Shigehisa KIYOSAWA
Keyword(s):  
Diurnal Variation ◽  
Day Length ◽  
Auxin Content

The callus model of plant flowering

1975 ◽  
Vol 190 (1100) ◽  
pp. 333-340 ◽  
Keyword(s):  
Nicotiana Sylvestris ◽  
Day Length ◽  
Nucleic Acid Metabolism ◽  
Glucose Content ◽  
Autonomous Regulation ◽  
Vegetative Buds ◽  
Photoperiodic Regulation ◽  
Auxin Content ◽  
Pyrimidine Bases ◽  
Protein Nucleic Acid

The callus model of flowering consists of cultures of stem calluses of three tobacco varieties, of photoperiodically neutral Trapesond, short-day Mammoth ( Nicotiana tabacum ) and long-day Sylvestris ( Nicotiana sylvestris ). Stem calluses of the Trapesond variety taken from flowering plants produce generative buds with flowers; those from young vegetating plants form vegetative buds. Stem calluses from both flowering and young vegetating plants of the Mammoth and Sylvestris varieties form only vegetative buds. The capacity for generative or vegetative morphogenesis is retained not only on prolonged cultivation of the primary calluses but also in passage culture. The differences in the ability of calluses to form generative or vegetative buds consists in the fact that in the photoperiodically neutral Trapesond variety all components of the hormone flowering complex are formed irrespective of day length in all parts of the plants, including the stems from which they are then transferred to the stem calluses (autonomous regulation); however, in the photoperiodically responsive Mammoth and Sylvestris varieties only part of the components of the hormone complex are formed autonomously whereas the others are produced as a result of biosynthesis which occurs in leaves under an optimal day length (photoperiodic regulation). At present the most promising seems to be a stem callus culture from neutral Wisconsin 38 and Trapesond plants. The ability of these calluses to form generative and vegetative buds is variable and changes on alteration of cultivation conditions. Formation of generative buds on stem calluses of these varieties occurs when the glucose concentration in the medium is sufficiently high and becomes more pronounced with increase of the content of the kinetin and some purine and pyrimidine bases. Vegetative buds are formed when the glucose content is low and increase of auxin content accelerates their formation. The callus model of flowering can be applied for comparative investigations of changes in the hormone complex and in protein-nucleic acid metabolism which occur at the transition from vegetative growth to flowering.

scholarly journals Dynamic Carbohydrate Supply and Demand Model of Vegetative Growth: Response to Temperature, Light, Carbon Dioxide, and Daylength

2017 ◽  
Author(s):  
Martin P.N. Gent
Keyword(s):  
Diurnal Variation ◽  
Dynamic Model ◽  
Growth Response ◽  
Supply And Demand ◽  
Co2 Enrichment ◽  
Day Length ◽  
Model Parameters ◽  
Demand Model ◽  
Environmental Responses ◽  
Response To Temperature

Predicting the growth response of seedlings from the environmental responses of photosynthesis and metabolism may be improved by considering the dynamics of non-structural carbohydrate, NSC, over a diurnal cycle. Attenuation of growth metabolism when NSC content is low could explain why some NSC is conserved through the night. A dynamic model, incorporating diurnal variation in NSC, was developed to simulate growth of seedlings hour-by-hour. I compared predictions of this model to published growth and NSC data for seedlings that varied according to temperature, light, day length, or CO2. Prolonged-darkness experiments showed a temperature dependent upper limit on the respiration capacity. Respiration was attenuated as NSC was depleted. Furthermore, when NSC was high at dawn, inhibition of photosynthesis could attenuate the accumulation of NSC under low temperature, or high light, or high CO2. These concepts were used to simulate plant metabolism and growth rates and diurnal variation of NSC in tomato seedlings under two light levels and various temperatures. Comparison of other results using the same model parameters showed the dynamic model could predict results for starch and starch-less plants, and when growth was affected by CO2 enrichment and day length.

Seasonal Variation in Flowering of Common Dandelion

Weed Science ◽  
1973 ◽  
Vol 21 (3) ◽  
pp. 230-232 ◽  
Author(s):  
Elmer Gray ◽  
Eugene M. McGehee ◽  
Don F. Carlisle
Keyword(s):  
Seasonal Variation ◽  
Diurnal Variation ◽  
Taraxacum Officinale ◽  
Day Length ◽  
Secondary Peak ◽  
Precipitation Temperature ◽  
Time Of Year ◽  
Common Dandelion

Seasonal variation in flowering of common dandelion (Taraxacum officinale Weber) was studied in 1969 and 1970 at Bowling Green, Kentucky. At this location the dandelion flowered throughout the year. Maximum flowering occurred during April and a secondary peak occurred in September and October. Number of flower stems per square meter was not significantly correlated with precipitation, temperature, or day length. Length of stem was positively correlated with temperature and day length. The plants exhibited diurnal variation in flowering habit. Number of times (or days) the heads opened and closed, length of time in which the heads remained open each day, and length of time heads remained closed before opening into mature heads (white balls) varied with time of year.

Fibrinolysis and Alimentary Lipaemia in Whites and Bantus; Their Relationship and Response to Intravenous Heparin

1964 ◽  
Vol 11 (01) ◽  
pp. 108-118 ◽  
Author(s):  
H Lackner ◽  
R Sougin-Mibashan
Keyword(s):  
Diurnal Variation ◽  
Fibrinolytic Activity ◽  
Butter Fat ◽  
Intravenous Heparin ◽  
The Difference

Summary and Conclusion1. Diurnal variation in fibrinolysis is marked in the Whites and almost absent in the Bantu. >2. The difference in fibrinolytic activity beween White and Bantu has been confirmed, but was found to decrease over the course of the morning due to diurnal variation in the White subjects.3. The ingestion of butter fat does not inhibit fibrinolysis to any appreciable extent in either White or Bantu.4. The accelerating effect of heparin on fibrinolysis was found to be present in lipaemic plasma, but appears to be distinct from the fat-clearing effect.

STUDIES ON DIURNAL VARIATION IN THYROID ACTIVITY

1962 ◽  
Vol 40 (3_Suppl) ◽  
pp. S149 ◽  
Author(s):  
A. Walser ◽  
H. Lüthy ◽  
H. R. Jenzer
Keyword(s):  
Diurnal Variation ◽  
Thyroid Activity

DIURNAL VARIATION OF PARTICULATE MATTER IN THE PROXIMITY OF ROVINARI FOSSIL-FUEL POWER PLANT

2011 ◽  
Vol 10 (1) ◽  
pp. 99-105 ◽  
Author(s):  
Catalin Nisulescu ◽  
Delia Calinoiu ◽  
Adrian Timofte ◽  
Andreea Boscornea ◽  
Camelia Talianu
Keyword(s):  
Particulate Matter ◽  
Power Plant ◽  
Diurnal Variation ◽  
Fossil Fuel ◽  
Fossil Fuel Power Plant
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