Growth and photosynthetic response of young ‘Navelina’ trees budded on to eight citrus rootstocks in response to iron deficiency

Figures & data

Table 1 Results of two-way analysis of variance (ANOVA) of rootstock (R) and Fe treatment (F) effects and their interaction (R×F) for the dependent variables considered.

	Independent variable
Dependent variable	R	F	R×F
Shoot dry mass	70.12^a*	127.36*	2.48*
Root dry mass	45.84*	22.20*	1.38 ns
Leaf number	20.97*	146.08*	6.80*
Shoot length	21.73*	117.75*	6.07*
SPAD	19.72*	385.63*	21.82*
PN	11.07*	354.90*	10.39*
E	13.72*	65.25*	6.74*
gS	6.41*	60.43*	1.24 ns
Ci	1.32 ns	0.82 ns	0.39 ns
WUE	12.61*	70.82*	2.46*

^a Numbers represent F values.

* P ≤ 0.05.

C_i, intercellular CO₂ concentration; E, leaf transpiration rate; g_S, stomatal conductance; ns, not significant; P_N, net photosynthetic rate; WUE, water use efficiency.

Table 2 Shoot dry mass (g) of ‘Navelina’ orange budded on different rootstocks under Fe sufficient and deprived conditions.

Rootstock	Control	(-)Fe	t-test	Mean	Loss (%)
Tuzcu 31 31 sour orange	29.12 ± 1.01^ab^1	26.24 ± 1.41^ab	ns	27.68^ab	9.88
Gou Tou sour orange	22.92 ± 1.97^cd	20.93 ± 2.44^d	ns	21.92^d	8.71
Volkameriana	30.83 ± 1.24^a	27.08 ± 2.13^a	ns	28.95^a	12.15
Cleopatra mandarin	25.98 ± 2.12^bc	22.84 ± 1.37^cd	ns	24.41^c	12.10
Carrizo citrange	28.64 ± 1.12^ab ^A2	23.87 ± 1.15^bcd ^B	* ^(2.283)	26.26^bc	16.68
Troyer citrange	30.81 ± 2.13^a ^A	25.52 ± 1.91^abc ^B	* ^(3.201)	28.17^ab	17.16
C-35 citrange	23.11 ± 1.17^cd ^A	17.32 ± 1.85^e ^B	* ^(4.292)	20.21^d	25.06
Local trifoliate	19.43 ± 1.64^d ^A	13.28 ± 1.87^f ^B	* ^(3.072)	16.35^e	31.66
Mean	26.36 ^A	22.13 ^B	* ^(3.652)
D0.01(Rootstock)^3	3.712	3.016		2.328

¹ Means followed by different letters (lower case) in the same column are significantly different (Tukey's multiple range test).

² Means followed by different letters (upper case) in the same row are significantly different (Student's t test, * P ≤ 0.05).

³ The value to compare the means at a significance level at α = 0.01 according to Tukey's multiple range test.

ns, not significant.

Table 3 Root dry mass (g) of ‘Navelina’ orange budded on different rootstocks under Fe sufficient and deprived conditions.

Rootstock	Control	(-)Fe	t-test	Mean	Loss (%)
Tuzcu 31 31 sour orange	15.59 ± 1.21^a	14.61 ± 1.18^a	ns	15.10^a	6.29
Gou Tou sour orange	8.91 ± 1.29^c	8.05 ± 2.15^cd	ns	8.48^cd	9.65
Volkameriana	17.06 ± 2.12^a	14.77 ± 1.94^a	ns	15.92^a	13.41
Cleopatra mandarin	10.31 ± 1.99^bc	9.02 ± 1.29^c	ns	9.67^c	12.53
Carrizo citrange	15.16 ± 1.09^a ^A	12.74 ± 1.63^ab ^B	* ^(1.018)	13.95^ab	15.93
Troyer citrange	13.29 ± 1.02^ab ^A	11.03 ± 1.27^bc ^B	* ^(1.276)	12.16^b	17.06
C-35 citrange	7.73 ± 0.38^c ^A	5.62 ± 1.61^d ^B	* ^(1.923)	6.67^d	27.31
Local trifoliate	7.69 ± 1.11^c ^A	5.08 ± 1.12^d ^B	* ^(2.013)	6.39^d	33.89
Mean	11.97 ^A	10.12 ^B	* ^(0.982)
D0.01(Rootstock)^3	3.982	3.066		2.447

¹ Means followed by different letters (lower case) in the same column are significantly different (Tukey's multiple range test).

² Means followed by different letters (upper case) in the same row are significantly different (Student's t test, * P ≤ 0.05).

³ The value to compare the means at a significance level at α = 0.01 according to Tukey's multiple range test.

ns, not significant.

Table 4 Leaf number of ‘Navelina’ orange budded on different rootstocks under Fe sufficient and deprived conditions.

Rootstock	Control	(-)Fe	t-test	Mean	Loss (%)
Tuzcu 31 31 sour orange	50.56 ± 3.21^b	43.56 ± 0.48^bc	ns	47.06^cd	13.84
Gou Tou sour orange	61.07 ± 2.29^ab	54.42 ± 3.16^ab	ns	57.75^ab	10.89
Volkameriana	55.76 ± 1.81^ab ^A	47.62 ± 1.19^abc ^B	* ^(4.998)	51.69^bc	14.59
Cleopatra mandarin	65.95 ± 1.29^a ^A	57.31 ± 3.31^a ^B	* ^(8.185)	61.63^a	13.10
Carrizo citrange	63.03 ± 0.74^a ^A	52.30 ± 0.66^ab ^B	* ^(2.298)	57.66^ab	17.03
Troyer citrange	63.05 ± 2.32^a ^A	50.45 ± 2.53^ab ^B	* ^(7.921)	56.75^ab	19.98
C-35 citrange	49.64 ± 2.56^b ^A	31.81 ± 1.85^d ^B	* ^(7.286)	40.72^d	35.93
Local trifoliate	67.23 ± 1.72^a ^A	37.83 ± 0.94^cd ^B	* ^(4.531)	52.53^bc	43.73
Mean	59.54 ^A	46.91 ^B	* ^(2.086)
D0.01(Rootstock)^3	11.659	11.314		6.545

¹ Means followed by different letters (lower case) in the same column are significantly different (Tukey's multiple range test).

² Means followed by different letters (upper case) in the same row are significantly different (Student's t test, * P ≤ 0.05).

³ The value to compare the means at a significance level at α = 0.01 according to Tukey's multiple range test.

ns, not significant.

Table 5 Shoot length (cm) of ‘Navelina’ orange budded on different rootstocks under Fe sufficient and deprived conditions.

Rootstock	Control	(-)Fe	t-test	Mean	Loss (%)
Tuzcu 31 31 sour orange	14.04 ± 1.03^cd	12.64 ± 0.63^ab	ns	13.34^a	9.97
Gou Tou sour orange	10.63 ± 0.39^d	9.75 ± 0.95^b	ns	10.19^e	8.28
Volkameriana	19.33 ± 0.83^ab ^A	15.33 ± 0.63^a ^B	* ^(2.418)	17.33^ab	20.69
Cleopatra mandarin	17.13 ± 0.63^bc ^A	14.00 ± 1.14^a ^B	* ^(3.014)	15.56^bcd	18.25
Carrizo citrange	20.87 ± 0.77^ab ^A	15.54 ± 1.18^a ^B	* ^(1.835)	18.20ab	25.54
Troyer citrange	16.60 ± 1.29^bc ^A	12.00 ± 1.04^ab ^B	* ^(3.829)	14.30^cd	27.71
C-35 citrange	22.54 ± 1.31^a ^A	14.38 ± 0.94^a ^B	* ^(3.028)	18.46^a	36.21
Local trifoliate	20.84 ± 1.01^ab ^A	11.67 ± 0.87^ab ^B	* ^(2.396)	16.26^abc	43.99
Mean	17.15 ^A	13.16 ^B	* ^(0.843)
D0.01(Rootstock)^3	5.265	3.928		2.647

¹ Means followed by different letters (lower case) in the same column are significantly different (Tukey's multiple range test).

² Means followed by different letters (upper case) in the same row are significantly different (Student's t test, * P ≤ 0.05).

³ The value to compare the means at a significance level at α = 0.01 according to Tukey's multiple range test.

ns, not significant.

Figure 1 A, Chl concentrations; B, net photosynthetic rate; C, transpiration rate; D, stomatal conductance; E, intercellular CO₂ concentration; F, water-use efficiency of ‘Navelina’ leaves on different rootstocks under Fe sufficient and deprived conditions. The bars show the standard deviation.

Figure 2 Regressions between: A, SPAD readings vs. P _N, and B, g _S vs. E.

Table 6 Correlation coefficient analysis between investigated parameters.

Variable	Shoot DM	Root DM	Leaf number	Shoot length	SPAD	PN	E	gS	Ci	WUE
Shoot DM	1.00	0.86***	0.43*	0.41*	0.41**	0.56*	0.43**	0.34*	0.26^ns	0.31^ns
Root DM		1.00	0.47*	0.49**	0.25^ns	0.34*	0.29^ns	0.30^ns	0.14^ns	0.24^ns
Leaf number			1.00	0.28*	0.61***	0.66***	0.44***	0.45***	0.16^ns	0.21^ns
Shoot length				1.00	0.45**	0.49**	0.39**	0.40**	0.12^ns	0.17^ns
SPAD					1.00	0.83***	0.35**	0.40**	−0.02^ns	0.43*
PN						1.00	0.51**	0.57**	0.16^ns	0.73***
E							1.00	0.83***	0.07^ns	−0.64**
gS								1.00	0.20^ns	−0.59*
Ci									1.00	0.28^ns
WUE										1.00
Mean	24.24	11.04	53.22	15.46	62.56	4.66	1.36	41.28	469.35	3.48
Std	5.02	4.08	10.57	4.12	16.42	1.75	0.49	19.31	20.85	1.10
N	128	128	128	128	128	80	80	80	80	80

*** P ≤ 0.001; ** P ≤ 0.01; * P ≤ 0.05.

C_i, intercellular CO₂ concentration; E, leaf transpiration rate; g_S, stomatal conductance; ns, not significant; P_N, net photosynthetic rate; Std, standard deviation; WUE, water use efficiency.