Table 1.

Effects of the drought on leaf pre-dawn water potential (Ψ_pd in MPa), rate of decrease of Ψ_pd (RDPWP in MPa d⁻¹ m⁻²), net CO₂ assimilation rate (A in μmol m⁻²s⁻¹), stomatal conductance (g_s in mmol m⁻² s⁻¹), internal to ambient CO₂ concentration ratio (C_i/C_a), maximum photochemical efficiency of PSII (F_v/F_m), quantum yield of PSII electron transport (Φ_PSII), photochemical (q_P) and Stern–Volmer non-photochemical (q_N) quenching coefficients, and the fraction of PPF absorbed in PSII antennae and used neither in photochemistry nor dissipated thermally (P_E) of clones 14, 22, and 120 of C. canephora

Different upper case letters denote significant differences among means of the two genotypes in irrigated conditions. Different lower case letters represent significant differences among means of the genotypes submitted to drought by the Newman–Keuls test at P ≤ 0.05 (clone effect). Means for plants submitted to drought marked with an asterisk differ from those of control plants by F-test at P ≤ 0.05 (treatment effect).

Parameters	Drought-tolerant clone (14)		Drought-sensitive clone (22)		Drought-tolerant clone (120)
	Control	Drought	Control	Drought	Control	Drought
Ψpd	–0.02±0.01 A	–3.02±0.12 a*	–0.03±0.00 A	–3.01±0.11 a*	–0.03±0.01 A	–3.1±0.15 a*
RDPWP	–	0.67±0.04 c	–	1.01±0.04 a	–	0.84±0.03 b
A	9.40±0.34 A	2.62±0.27 a*	9.35±0.17 A	0.95±0.23 b*	9.62±0.61 A	2.57±0.14 a*
g s	60.00±5.00 B	13.00±3.50 a*	105.00±9.50 A	5.00±3.00 a*	72.00±7.00 B	10.00±1.00 a*
C i/C a	0.520±0.040 B	0.380±0.040 b*	0.670±0.040 A	0.520±0.040 a*	0.520±0.050 B	0.320±0.050 b*
F v/F m	0.840±0.011 A	0.842±0.011 a	0.831±0.011 A	0.800±0.011 b*	0.830±0.001 A	0.850±0.004 a
ΦPSII	0.455±0.049 A,B	0.287±0.050 a,b*	0.472±0.049 B	0.210±0.050 b*	0.577±0.048 A	0.395±0.046 a*
q P	0.713±0.051 A,B	0.495±0.051 a,b*	0.697±0.051 B	0.362±0.051 b*	0.815±0.033 A	0.615±0.055 a*
q N	0.665±0.056 A	0.717±0.057 a	0.642±0.056 A	0.543±0.057 a	0.560±0.067 A	0.652±0.021 a
P E	0.252±0.040 A	0.425±0.040 a,b*	0.242±0.039 A	0.508±0.039 a*	0.152±0.027 A	0.332±0.048 b*