Table 4.

Correlation coefficients of the stable isotopes with biomass and gas exchange parameters for all the treatments and genotypes together.

		AB	SB	gs	E	Tcum
Low N	Δ18Os	–0.79**	–0.89**	0.15	0.18	–0.84**
	Δ13Cs	–0.48	–0.13	0.29	–0.02	–0.38
	Δ13Cs /Δ18Os	–0.02	0.34	0.17	–0.11	0.09
High N	Δ18Os	–0.72**	–0.80**	–0.58*	–0.71*	–0.80**
	Δ13Cs	0.11	0.63*	0.74**	0.67*	0.13
	Δ13Cs /Δ18Os	0.18	0.80**	0.80**	0.80**	0.40

Linear correlations were calculated within each N treatment using water and genotype means (n=12), *P<0.05, **P<0.01.

AB, aboveground biomass; SB, spike biomass; g_s, stomatal conductance; E, transpiration rate; T_cum, cumulative transpiration.