Photosynthetic response of carrots to varying irradiances

Title:

Photosynthetic response of carrots to varying irradiances

Creator:

Kyei-Boahen, S., Lada, R., Astatkie, T., Gordon, R., and Caldwell, C.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:f07395a8-cb9a-4ec3-85d9-29f3e3f8dfa8
uuid:f07395a8-cb9a-4ec3-85d9-29f3e3f8dfa8
issn:0300-3604
doi:10.1023/B:PHOT.0000011967.74465.cc

Subject:

compensation irradiance, Daucus carota, net photosynthetic rate, nonlinear regression model, quantum yield, stomatal conductance, transpiration rate, and water use efficiency

Type:

model:article and TEXT

Format:

bez média and svazek

Description:

Response to irradiance of leaf net photosynthetic rates (PN) of four carrot cultivars: Cascade, Caro Choice (CC), Oranza, and Red Core Chantenay (RCC) were examined in a controlled environment. Gas exchange measurements were conducted at photosynthetic active radiation (PAR) from 100 to 1 000 μmol m-2 s-1 at 20 °C and 350 μmol (CO2) mol-1(air). The values of PN were fitted to a rectangular hyperbolic nonlinear regression model. PN for all cultivars increased similarly with increasing PAR but Cascade and Oranza generally had higher PN than CC. None of the cultivars reached saturation at 1 000 μmol m-2 s-1. The predicted PN at saturation (PNmax) for Cascade, CC, Oranza, and RCC were 19.78, 16.40, 19.79, and 18.11 μmol (CO2) m-2 s-1, respectively. The compensation irradiance (I c) occurred at 54 μmol m-2 s-1 for Cascade, 36 μmol m-2 s-1 for CC, 45 μmol m-2 s-1 for Oranza, and 25 μmol m-2 s-1 for RCC. The quantum yield among the cultivars ranged between 0.057-0.033 mol(CO2) mol-1(PAR) and did not differ. Dark respiration varied from 2.66 μmol m-2 s-1 for Cascade to 0.85 μmol m-2 s-1 for RCC. As PN increased with PAR, intercellular CO2 decreased in a non-linear manner. Increasing PAR increased stomatal conductance and transpiration rate to a peak between 600 and 800 μmol m-2 s-1 followed by a steep decline resulting in sharp increases in water use efficiency. and S. Kyei-Boahen ... [et al.].

Language:

Multiple languages

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Coverage:

301-305

Source:

Photosynthetica | 2003 Volume:41 | Number:2

Harvested from:

CDK

Metadata only:

false