Table 4.

Plant water relations, growth, and stable isotopes of S. italica grown under well-watered, moderately and severely water-limited treatments and harvested during two collection periods

One-way ANOVAs were conducted on each variable as described in ‘Materials and methods’. The source water used to calculate Δ¹⁸O_LW and Δ¹⁸O_BL was root crown water. P-values are reported in the right column (***P<0.001, **P<0.01, *P<0.05, ns P>0.05). Means±SE were calculated for each variable, and within the same row, means followed by the same letter were not significantly different. Other factors also were analysed and are given in Supplementary Tables S3 and S4.

Variables	Well-watered	Water limitation		ANOVA
		Moderate	Severe	P
Total water use (l)	12.65 ± 0.88a	3.77 ± 0.07b	2.57 ± 0.06c	***
Fresh aboveground biomass (g)	486.1 ± 36.4a	140.7 ± 6.3b	100.4 ± 3.3c	***
Dry aboveground biomass (g)	104.7 ± 8.0a	33.4 ± 1.3b	24.9 ± 1.1c	***
Number of tillers	9.2 ± 1.6a	6.6 ± 1.0a	7.9 ± 0.9a	ns
Δ18OLW	21.5 ± 0.8a	20.8 ± 1.0a	20.6 ± 1.3a	ns
Δ18OBL	42.1 ± 0.5a	40.8 ± 0.4ab	40.1 ± 0.5b	*
δ13CBL	−12.96 ± 0.06a	−13.88 ± 0.10b	−13.81 ± 0.11b	***
δ18OSW	−16.2 ± 0.1c	−14.2 ± 0.2b	−13.0 ± 0.1a	***
δ18ORC	−15.9 ± 0.1c	−13.9 ± 0.2b	−12.7 ± 0.3a	***
C i/Ca	0.44 ± 0.01a	0.30 ± 0.01b	0.27 ± 0.01b	***
g s (mmol−1 H2O m−2 s−1)	0.173 ± 0.019a	0.119 ± 0.019b	0.110 ± 0.009b	***
E (mmol−1 H2O m−2 s−1)	2.13 ± 0.16a	1.59 ± 0.19b	1.48 ± 0.12b	***
A net (µmol−1 CO2 m−2 s−1)	20.3 ± 1.4a	18.1 ± 2.1b	17.4 ± 0.8b	***
Water per leaf area (l H2O m−2 dry leaf)	0.19 ± 0.008a	0.17 ± 0.013ab	0.15 ± 0.009b	*
TEinstantaneous (Anet/E)	9.6 ± 0.2b	11.4 ± 0.3a	11.8 ± 0.2a	***
TEintrinsic (Anet/gs)	118.4 ± 3.39b	153.2 ± 3.25a	158.1 ± 3.08a	***
TEplant (g biomass l H2O transpired−1)	8.25 ± 0.22b	8.89 ± 0.34ab	9.69 ± 0.36a	*
TEw (mmol C mol H2O−1; derived from δ13CBL)	4.94 ± 0.09b	6.49 ± 0.19a	6.37 ± 0.17a	***
Leaf length (cm)	43.9 ± 1.9a	33.2 ± 1.4b	28.0 ± 1.0c	***