scholarly journals Is the abaxial palisade parenchyma in phyllaries of the sunflower (Helianthus annuus L.) capitulum a missing trait in modern genotypes?

Phyton ◽  
2016 ◽  
Vol 85 (1) ◽  
pp. 291-296
Author(s):  
Hern醤dez LF ◽  
MV Rosetti
2013 ◽  
Vol 37 (1) ◽  
pp. 5-16
Author(s):  
Adam Tomaszewski ◽  
Elżbieta Weryszko-Chmielewska ◽  
Grzegorz Skrodzki

The influence of two morphactins (IT 3233 and IT 3456) on the formation of tissues in sunflower leaves was investigated. The leaves were usually smaller, they had plicate laminae and rolled up edges. The different influence of morphactins in dependence on the position of the leaves on the stem and on the kind of tissues was confirmed. Leaves growing from the first node had the thickest laminae, main ribs and the longest cells of palisade parenchyma. The values contrasted with those in the leaves from the third node. An increase of the number of epidermis cells and stomata in leaves from the first and second node and a decrease in those from the third node were observed. Additional layers (1-2) of palisade parenchyma in leaves of the second and third node were formed. Mesophyll was very compact. Xylem consisted of a greater number of elements, arranged compactly and of much lower diameter.


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

2014 ◽  
Vol 2014 (2) ◽  
pp. 83-91
Author(s):  
Alfredo Garcia-Perez ◽  
◽  
Mark Harrison ◽  
Bill Grant ◽  
◽  
...  

Helia ◽  
2000 ◽  
Vol 23 (33) ◽  
pp. 97-104
Author(s):  
F.M. Khalifa ◽  
A.A. Schneiter ◽  
E.I. El Tayeb

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.


Helia ◽  
2001 ◽  
Vol 24 (35) ◽  
pp. 101-110 ◽  
Author(s):  
S. Sridhara ◽  
T.G. Prasad

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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