Phenotypic traits measurement
Phenotypic traits were measured for each clone. Plants with apparently
abnormal values were checked immediately and the values corrected
whenever necessary. To investigate the influence of Cd on
photosynthesis, we measured net photosynthetic rate (A) in mornings
between 8-11 am on sunny days, using a Li-6800 portable InfraRed Gas
Analyser (IRGA). Chlorophyll content was extracted using the acetone
method (Su et al., 2010) and measured using a spectrophotometer. Actual
quantum efficiency of PSⅡ (YⅡ) shows the actual light energy conversion
efficiency, and maximum quantum efficiency of PSⅡ (Fv/Fm) shows the
maximum efficiency of PSII which converts absorbed light energy into
chemical energy. We first placed the plants in darkness for 30 minutes
as a pretreatment, and then measured YⅡ, Fv/Fm and electron transfer
efficiency (ETR) in photosynthesis of healthy leaves using PAM-2500,
DualPam-100. Ion leakage rate (ILR) as an indicator of cell membrane
damage, was measured using conductivity meter (FiveEasy Plus™, Mettler
Toledo, Switzerland). Leaf cadmium after high Cd treatment was separated
by boiling with concentrated nitric acid, and measured using an
ICP-MS,Thermo Fisher iCAP RQ,America. Multiple comparisons based on
Turkey’s post-hoc HSD test was performed with ANOVA by the R packageagricolae (Mendiburu, 2019) to test the differences among groups
in physiological traits due to Cd treatments.