Portable photosynthesis system

To determine the levels of chlorophyll and carotenoids in a leaf sample, 0.25 g of frozen leaves were crushed using liquid nitrogen in a Chinese mortar. Subsequently, 20 ml of 80% acetone was added to the sample and then centrifuged at 4800 rpm for 20 min. The sample’s luminescent absorption was noted at 470, 647, and 663 nm using a spectrophotometer. Finally, the total amount of chlorophyll and carotenoids was calculated by Lichtenthaler’s method [18 (link)].
Gas exchange parameters of plants were measured using a portable photosynthesis system provided by ADC BioScientific Ltd, Hoddesdon, UK. These parameters include the net photosynthetic CO₂ assimilation rate (A, µmol CO₂ m^− 2 s^− 1) and stomatal conductance (gs, mol H₂O m^− 2 s^− 1). The measurements were taken on completely expanded leaves at around 9:00 AM and 12:00 PM, 60 days after planting.

Plant gas exchange parameters include net CO₂ assimilation rate (A, μmol CO₂ m⁻² s⁻¹), intrinsic water-use efficiency (WUE_i, μmol CO₂ mol H₂O⁻¹), stomatal conductance (G_s, mol H₂O m⁻² s⁻¹), transpiration (E, mmol H₂O m⁻² s⁻¹), Sub-stomatal CO₂ concentration (C_i, μmol CO₂ mol⁻¹) and, instantaneous carboxylation efficiency (A/C_i) were measured using a portable photosynthesis system (ADC BioScientific Ltd, Hoddesdon, UK) after 60 days after planting. Around 9:00 AM and 12:00 AM, measurements were performed on completely expanded leaves.

Plant gas exchange parameters include net CO₂ assimilation rate (A, μmol (CO₂) m⁻² s⁻¹), water-use efficiency (WUE (A/E), μmol CO₂ mol H₂O⁻¹), stomatal conductance (g_s, mol H₂O m⁻².s⁻¹), transpiration (E, mmol H₂O m⁻².s⁻¹), Sub-stomatal CO₂ concentration (C_i, μmol CO₂ mol^-1) and, instantaneous carboxylation efficiency (A/C_i) were measured using a portable photosynthesis system (ADC BioScientific Ltd, Hoddesdon, UK) 60 days after planting. Measurements were made 30 days after applying the treatments and when the leaves were mature. Around 9:00 AM and 12:00 AM, measurements were performed on completely expanded leaves^{19 (link)}.