Effects of leaf age, nitrogen nutrition and photon flux density on the organization of the photosynthetic apparatus in leaves of a vine (Ipomoea tricolor Cav.) grown horizontally to avoid mutual shading of leaves

Planta ◽  
1996 ◽  
Vol 198 (1) ◽  
Author(s):  
Kouki Hikosaka

1995 ◽  
Vol 22 (3) ◽  
pp. 425 ◽  
Author(s):  
FW Badeck

A model on the allocation of nitrogen available for the construction of photosynthetic apparatus in leaves in different morphological positions is presented. The allocation pattern is calculated under the assumption that nitrogen distribution is optimised in order to maximise daily whole-plant assimilation. The solution is fairly sensitive to the assimilation function applied. It is shown that assimilation functions homogeneous in irradiance and nitrogen imply assimilation gradients and light-saturation characteristics of the whole canopy which contradict experimental findings. An equation for the calculation of electron transport rates as a function of the intra-leaf gradient of the photosynthetic photon flux density is presented. This inhomogeneous assimilation function leads to substantially different predictions of nitrogen allocation which reproduce a wider array of observed allocation patterns. The results presented in this paper support the thesis that the intra-leaf gradient of photosynthetic photon flux density and self-shading of the thylakoids need to be considered if the assimilation flux is to be modelled as a function of light as well as nitrogen availability on a mechanistic basis.



Oecologia ◽  
1998 ◽  
Vol 113 (3) ◽  
pp. 314-324 ◽  
Author(s):  
N. P. R. Anten ◽  
K. Miyazawa ◽  
K. Hikosaka ◽  
H. Nagashima ◽  
T. Hirose


1982 ◽  
Vol 18 (4) ◽  
pp. 375-382 ◽  
Author(s):  
Jairo A. Palta

SUMMARYGas exchange measurements were carried out on four cassava cultivars, M. COL22, M. MEX59, M. COL638, and M. VEN218, under a range of light intensities, to investigate possible differences in photosynthesis and transpiration. Over the range of photon flux density 100–1500 μE m−2 s−1 leaves showed a light saturation response typical of C-3 plants with little increase in photosynthetic rate above 1000–1500 μE m−2 s−1 (200–300 Wm−2 PAR). At light saturation there were significant differences in photosynthetic rates between cultivars, with the highest 10% greater than the lowest. Part of the response could be attributed to increased stomatal aperture, and a greater part to a direct effect of light intensity on the photosynthetic apparatus. Transpiration increased with light intensity levels, but no significant differences were observed between cultivars.





1977 ◽  
Vol 55 (17) ◽  
pp. 2288-2295 ◽  
Author(s):  
M. Aslam ◽  
S. B. Lowe ◽  
L. A. Hunt

The effect of plant and leaf age on CO2-exchange rates (CER) and transpiration rates in 15 genotypes of cassava (Manihot esculenta Crantz) was measured in situ by infrared gas analysis. The plants were grown in a controlled-environment room with a 14-h photoperiod, day–night temperatures of 29–24 °C, and 60–70% relative humidity.Plant age had no effect on leaf CER, whereas transpiration rates in 14-week-old plants were significantly greater than those in 7-week-old plants. Both CER and transpiration rates decreased with leaf age. The decline was negligible when measured at low photosynthetic photon flux density. At saturating light, however, both CER and transpiration rates decreased significantly in most of the genotypes. Significant genotypic differences were observed in the pattern of decline. Both stomatal (rs) and residual (rr) resistances to the diffusion of CO2 increased with leafage in all the genotypes. The relative increase in rr was much greater than the increase in rs. In all the genotypes the ratio rr:rs was greater than unity, suggesting that rr is the major component of the total resistance to photosynthesis. Chlorophyll content and specific leaf weight also varied significantly among the genotypes. However, chlorophyll content decreased and specific leaf weight increased with leaf age.





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