Nitrogen use efficiency and genotype-by-environment interaction in durum wheat genotypes under varying nitrogen supply

Figures & data

Figure. Monthly average rain fall, maximum and minimum temperature of the experimental sites during the year 2021. DZ = Debre Zeit, CD = Chefe Donsa and MJ = Minjar.

Table 1. Soil chemical and physical properties of experimental locations.

Soil properties	Locations			Methods used
	Debre Zeit	Chefe Donsa	Minjar
pH	6.74	7.39	7.64	1:2.5 soil water ratio
Electric conductivity (ds m^−1)	0.06	0.05	0.09	Potentiometric
Organic Carbon (%)	2.82	2.80	3.60	(Walkley and Black 1934)
Phosphorus (mg kg^−l)	32.08	7.49	14.86	(Olsen et al. 1954)
Total Nitrogen (%)	0.08	0.11	0.09	Kjeldahl (Bremner and Breitenbeck 2008)
Clay (%)	57.6	65.6	55.6	Hydrometer
Silt (%)	30.8	18.8	20.8	Hydrometer
Sand (%)	11.6	15.6	23.6	Hydrometer
Bulk Density (g cm^−3)	1.23	1.25	1.31	USDA model
Soil mass at 0.2 m depth (kg ha^−l)	2,460,000	2,500,000	2,620,000	M=BD×Depth×Area
Available N (mg kg^−l of soil)	46.2	21.4	44.7	Devardas (Liao 1981)
Total N (kg ha^−1)	1,968	2,750	2,358	TN×M/100
Available N (kg ha^−1)	113.7	53.5	117.1	Available N×M

Table 2. Description of durum wheat genotypes used for the experiment.

No.	Genotypes	Source	Pedigree/ID/Accessions
1	Farmers’ variety	EBI	222415
2	FIGSDRYWET108	ICARDA	IRNS294/ID-98797
3	FIGSDRYWET0144	ICARDA	IRNS382/ID-119026
4	Farmers’ variety	EBI	226958
5	CD15DZELT/off/1239/2015	CIMMYT	GER0MTEL–3/8/ST0T//ALTAR84/ALD/3/THB/CEP7780//2×MUSK-4/6/EC0/CMH76A.722// …
6	CD15DZ_ELT/off/1006/2015	CIMMYT	JUPAREC2001 × 2/RBC/6/STORLOM/3/RASCON-37/TARRD-2//RASCON-37/4/D00003A/5/ …
7	CD15DZELT/off/1516/2015	CIMMYT	JUPARE C 2001 × 2/IM/5/K0FA/4/DUKEM1//PA TKA-7/YAZI-1/3/PATKA-7/YAZI-1/6/ALAS/ …
8	Farmers’ variety	EBI	231585
9	Farmers’ variety	EBI	208215
10	FIGSDRYWET078	ICARDA	AFG68:77/ID-90233
11	Variety Tesfaye	DZARC	ARMENT//SRN-NIGRIS-4/3/CANED-9.1/4/TOSKA-26RASCON-37//SNITSN/5/PLAYERO
12	Farmers’ variety	EBI	231584
13	Breeding pipleline, DWNL p#16	DZARC	BHA/15/MOHAWK/4/DUKEM-1//PATKA-7/YAZI-1/3/PATKA-7/YAZI-1/6/CF4 20S/4/YAZI-1/ …
14	FIGSDWHOTCLD015	ICARDA	ETH732:91/ID-81510
15	CD15DZELT/off/935/2015	CIMMYT	C0RDEIR0/9/GUAYACANINIA/GUANY/8/GEDIZ FG0//GTA/3/SRN-1/4/TOTUS/5/ENTE/MEXI-2// …
16	Breeding pipleline, DWNL p#5	DZARC	Yerer/UC11132 … .25Yellow/DZ2013mehF1 P#6/DZ2014meh F2 P#6–1

EBI = Ethiopian Biodiversity Institute, CIMMYT = International Wheat and Maize Improvement Center, ICARDA = International Center for Agricultural Research in the Dry Areas, and DZARC = Debre Zeit Agricultural Research Center.

Table 3. Mean squares, means and coefficients of variation from the combined analysis of variance of grain yield (GYD) and N use efficiency components of durum wheat genotypes under high and low N conditions over three locations.

Traits	N levels	Mean squares					Grand mean	LSD (0.05)	CV (%)
		Geno. (df = 15)	Loc. (df = 2)	Rep. (df = 2)	Geno*Loc. (Df = 30)	Error (df = 94)
GYD	LN	1.9**	58.2**	0.6^ns	0.4^ns	0.3	2.9	0.5	18.1
	HN	5.6**	47.4**	0.9^ns	0.7*	0.4	4.9	0.6	13.1
BNY	LN	827.6**	38170.3**	612.7^ns	413.9*	260.6	70.7	15.1	22.8
	HN	693.0**	23307.5**	781.8^ns	338.7^ns	291.6	131.6	15.9	12.9
NUpE	LN	0.08**	0.07^ns	0.02^ns	0.04^ns	0.02	0.7	0.1	21.1
	HN	0.02**	0.03*	0.03^ns	0.01^ns	0.01	0.7	0.1	12.5
NHI	LN	39.5**	4.2^ns	29.7^ns	62.8**	10.9	79.6	3.09	4.1
	HN	261.4**	35.2^ns	10.6^ns	31.3^ns	15.8	76.2	3.7	5.2
NUtE	LN	66.9**	2532.8**	6.4^ns	36.2**	4.5	43.1	1.9	4.9
	HN	203.9**	1284.1**	10.1^ns	13.1 **	4.6	37.2	2.0	5.8
NUE	LN	194.1**	1684.1**	12.5^ns	25.9^ns	28.8	31.8	5.0	16.8
	HN	156.9**	509.2**	29.1^ns	17.8*	10.7	26.4	3.1	12.4

** and *= significant at p< 0.001 and p< 0.05 respectively, ns = non-significant, GYD = grain yield, BNY = above ground biomass N yield, NUPTE = N uptake efficiency, NHI = N harvest index, NUTE = N utilization efficiency and NUE = N use efficiency.

Table 4. Mean grain yield and above ground biomass N yield of6 durum wheat genotypes over the three locations.

Durum wheat genotypes	Grain Yield (t ha^−1)		Above ground biomass N yield (kg ha^−1)
	Low N	High N	Low N	High N
1 (Farmers; variety)	3.57^abc	4.86^cd	86.1^a	136.4^abc
2 (FIGSDRYWET108)	2.96^d-^h	3.30^g	73.9^a-^e	114.4^e
3 (FIGSDRYWET0144)	3.24^b-^e	5.67^ab	76.1^a-^d	143.7^a
4 (Farmers’ variety)	3.08^c-^g	4.14^ef	76.6^abc	137.7^abc
5 (CD15DZELT/off/1239/2015)	3.78^a	6.22^a	76.2^a-^d	142.0^ab
6 (CD15DZ_ELT/off/1006/2015)	3.16^b-^f	5.25^bc	77.6^ab	135.2^a-^d
7 (CD15DZELT/off/1516/2015)	3.30^a-^d	5.13^bc	73.0^a-^e	126.8^b-^e
8 (Farmers’ variety)	3.41^ab	4.12^ef	86.9^a	130.9^a-^d
9 (Farmers’ variety)	2.78^e-^i	3.67^fg	76.1^a-^d	120.2^cde
10 (FIGSDRYWET078)	2.30^i	5.58^b	54.9^f	142.7^ab
11 (Variety Tesfaye)	2.63^ghi	4.89^cd	64.3^b-^f	122.6^cde
12 (Farmers; variety)	2.52^hi	4.40^de	59.4^ef	130.1^a-^e
13 (Breeding pipleline, DWNL p#16)	2.45^i	4.91^cd	61.3^def	123.3^cde
14 (FIGSDWHOTCLD015)	2.70^f-^i	5.29^bc	62.5^b-^f	138.3^abc
15 (CD15DZELT/off/935/2015)	2.55^hi	5.17^bc	61.7^c-^f	125.7^cde
16 (Breeding pipleline, DWNL p#5)	2.49^hi	5.71^ab	64.3^b-^f	136.3^abc
Grand mean	2.9	4.9	70.7	131.4
LSD(<0.05)	0.5	0.6	15.11	15.98
CV	18.1	13.1	22.8	12.9

Means in the same columns followed by the same letter(s) are not significantly different at p ≤ 0.05.

Figure 2. Average grain yields (a) and above ground biomass N yield (b) of durum wheat genotypes at the three experimental sites under low and high N growth conditions (the different small and capital letters indicate the presence of significant difference between sites under low N and high N, respectively).

Figure 3. Average N uptake efficiency (NUpE) of durum wheat genotypes across the three locations under high and low N (the different small and capital letters indicate the presence of significant difference between sites under low N and high N, respectively).

Figure 4. Average nitrogen harvest index (NHI) values across the three locations of durum wheat genotypes under high and low N growth conditions (the different small and capital letters indicate the presence of significant difference between sites under low N and high N, respectively).

Table 5. Mean nitrogen utilization efficiency (NUtE) and nitrogen use efficiency (NUE) of6 durum wheat genotypes over the three locations.

Durum wheat genotypes	Nitrogen utilization efficiency (kg kg^−1)		Nitrogen use efficiency (kg kg^−1)
	Low N	High N	Low N	High N
1 (Farmers; variety)	44.7^bc	35.5^e	37.8^abc	26.2^ef
2 (FIGSDRYWET108)	40.2^fg	28.6^g	32.7^d-^g	18.2^i
3 (FIGSDRYWET0144)	44.1^bc	39.7^cd	34.2^b-^e	30.1^bc
4 (Farmers’ variety)	41.6^def	30.4^fg	33.9^b-^f	22.6^g
5 (CD15DZELT/off/1239/2015)	51.2^a	43.9^a	40.3^a	33.3^a
6 (CD15DZ_ELT/off/1006/2015)	43.0^cde	39.2^d	33.8^c-^f	28.1^b-^e
7 (CD15DZELT/off/1516/2015)	45.4^b	41.3^bc	34.8^bcd	27.5^cde
8 (Farmers’ variety)	44.3^bc	31.6^f	39.1^ab	22.1^gh
9 (Farmers’ variety)	39.5^g	30.6^f	29.5^e-^h	19.5^hi
10 (FIGSDRYWET078)	43.2^cd	39.1^d	25.7^h	30.0^bcd
11 (Variety Tesfaye)	41.6^def	40.2^bcd	29.1^fgh	26.5^ef
12 (Farmers; variety)	42.9^cde	34.3^e	27.3^h	23.6^fg
13 (Breeding pipleline, DWNL p#16)	41.2^efg	39.9^cd	27.5^h	27.0^de
14 (FIGSDWHOTCLD015)	43.1^cde	38.2^d	29.1^fgh	28.5^b-^e
15 (CD15DZELT/off/935/2015)	43.1^cde	41.5^ab	27.9^gh	27.9^b-^e
16 (Breeding pipleline, DWNL p#5)	40.7^fg	41.9^ab	26.6^h	30.7^ab
Grand mean	43.1	37.3	31.8	26.4
LSD(<0.05)	1.99	2.01	5.02	3.06
CV (%)	4.9	5.8	16.8	12.4

Means in the same columns followed by the same letter(s) are not significantly different as judged by LSD at p ≤ 0.05.

Figure 5. Average nitrogen utilization efficiency (a) and nitrogen use efficiency (b) of durum wheat genotypes at the three experimental sites under low N and high N growth conditions (the different small and capital letters indicate the presence of significant difference between sites under low N and high N, respectively).

Figure 6. Relative proportions of grain and straw N uptake by durum wheat genotypes under (a) Low N and (b) High N supply.

Table 6. Simple correlation coefficients among yield and nitrogen use efficiency component variables of durum wheat genotypes under high N (upper diagonal) and low N (below diagonal) conditions.

Traits	BNY	NUpE	NHI	NUtE	NUE	BM	GYD
BNY	1.00	0.59**	0.24**	−0.04ns	0.32**	0.43**	0.71**
NUpE	0.68**	1.00	0.20*	0.01ns	0.61**	0.01ns	0.42*
NHI	−0.05ns	−0.11ns	1.00	0.64**	0.62**	−0.38**	0.59**
NUtE	−0.47**	−0.11ns	0.30**	1.00	0.79**	−0.20*	0.66**
NUE	0.26**	0.75**	0.09ns	0.56**	1.00	−0.16ns	0.78**
BM	0.89**	0.64**	−0.07ns	−0.22**	0.40**	1.00	0.19*
GYD	0.90**	0.63**	0.06ns	−0.09ns	0.49**	0.91**	1.00

* and ** = significant at p < 0.05 and p < 0.001 respectively, ns = non-significant, GYD = Grain yield, BM = Above-ground biomass yield, BNY = above-ground biomass N yield, NUpE = N uptake efficiency, NHI = N harvest index, NUtE = N utilization efficiency, and NUE=N use efficiency.

Figure 7. GGE biplot for six environments and grain yield of6 durum wheat genotypes tested under low and high N conditions at three locations. The numbers–16 indicate the genotype codes. DZLN = Debre Zeit under low N, DZHN = Debre Zeit high N, CDLN = Chefe Donsa low N, CDHN = Chefe Donsa high N, MJLN = Minjar low N and MJHN = Minjar high N.

Figure 8. Adaptability and performance of durum wheat genotypes with respect to test environments. The numbers–16 indicate the genotype codes. DZLN = Debre Zeit under low N, DZHN = Debre Zeit high N, CDLN = Chefe Donsa low N, CDHN = Chefe Donsa high N, MJLN = Minjar low N and MJHN = Minjar high N.

Table 7. Mean grain yield, AMMI stability value and yield stability index for the6 durum wheat genotypes tested across the six environments.

Genotypes	Mean Yield	ASV	Rank of ASV	YSI	Rank of YSI
1 (Farmers; variety)	4.22	1.59	10	13	3
2 (FIGSDRYWET108)	3.14	3.69	16	32	16
3 (FIGSDRYWET0144)	4.45	1.42	8	10	2
4 (Farmers’ variety)	3.61	2.02	11	24	13
5 (CD15DZELT/off/1239/2015)	5.00	1.22	6	7	1
6 (CD15DZ_ELT/off/1006/2015)	4.22	0.40	3	7	4
7 (CD15DZELT/off/1516/2015)	4.20	0.36	2	7	5
8 (Farmers’ variety)	3.88	3.06	15	24	9
9 (Farmers’ variety)	3.23	2.13	12	27	15
10 (FIGSDRYWET078)	3.94	2.88	14	22	8
11 (Variety Tesfaye)	3.76	0.76	4	15	11
12 (Farmers; variety)	3.46	0.13	1	15	14
13 (Breeding pipleline, DWNL p#16)	3.68	1.12	5	17	12
14 (FIGSDWHOTCLD015)	4.01	1.54	9	16	7
15 (CD15DZELT/off/935/2015)	3.86	1.34	7	17	10
16 (Breeding pipleline, DWNL p#5)	4.09	2.67	13	19	6

ASV = AMMI stability value and YSI = Yield stability index.

Walkley A., Black I.A. 1934. An examination of the degtjareff method for determining soil organic matter, and a proposed modification of the chromic acid titration method. Soil Sci. 37(1):29–38. doi: 10.1097/00010694-193401000-00003.

 Google Scholar

Olsen S.R., Cole C.V., Watandbe F., Dean L. 1954. Estimation of available phosphorus in soil by extraction with sodium bicarbonate. J Chem Inf Model. 53(9):1689–1699.

 Google Scholar

Bremner J.M., Breitenbeck G.A. 2008. A simple method for determination of ammonium in semimicro-Kjeldahl analysis of soils and plant materials using a block digester. Commun Soil Sci Plant Anal. 14(10):905–913. doi: 10.1080/00103628309367418.

 Google Scholar

Liao C.F.H. 1981. Devarda’s alloy method for mitrogen determination. Soil Sci Soc Amer J. 45(5):852–855. doi: 10.2136/SSSAJ1981.03615995004500050005X.

 Web of Science ®Google Scholar

Data availability statement

The data presented in this study are available upon request from the corresponding authors.