Growth Responses and Nitrogen Uptake by Saltgrass (Distichlis spicata L.), a Halophytic Plant Species, under Salt Stress, Using the ¹⁵N Technique

Table 7

Total nitrogen and ¹⁵N contents (mg) of various clones of saltgrass root tissues under the control and salt (NaCl) stress conditions.

Grass clones ID	Root total N content		Root ^15N content
	Treatment		Treatment
	Control, 0.95 dSm^−1 (608 mg L^−1)	EC 20 dSm^−1 (12,800 mg L^−1)	Control, 0.95 dSm^−1 (608 mg L^−1)	EC 20 dSm^−1 (12,800 mg L^−1)
	(mg)
72	14.73b	21.35a	0.44ab	0.50a
240	7.74c	13.53b	0.21c	0.36b
A138	6.81c	7.28c	0.19c	0.20c
A37	6.59c	6.45c	0.11cdefg	0.18cd
A86	6.12c	6.70c	0.17cde	0.16cdef
A60	5.17cd	6.62c	0.15cdefg	0.18cd
A136	5.15cd	6.39c	0.15cdefg	0.16cdef
A50	4.42de	6.37c	0.12cdefg	0.17cde
A107	3.63def	6.04c	0.08defg	0.14cdefg
A49	2.55ef	5.63cd	0.06fg	0.13cdefg
A126	2.03f	3.71def	0.05g	0.08defg
239	1.93f	3.56def	0.05g	0.07efg

Values are total N and ¹⁵N contents of the roots, averages of 4 replications at the final harvest for both experiments.
Values for Total-N or ¹⁵N content for control and salt stress treatment columns compared together followed by the same letters are not statistically different at the 0.05 probability level.