Evaluation of candidate orange-fleshed sweetpotato clones for nutritional traits

Figures & data

Table 1. Description of the experimental sites.

Location	Code	Altitude (masl)^a	Agro-ecological zones	Coordinates	Annual rainfall (mm)	Mean annual temperature (°C)		RH (%)
						Min	Max
Arbaminch	AM	1400	sub-moist warm	06°03′N, 37°33′E	940.9	17.4	30.6	55.9
Areka	ARE	1752	moist-cool	07°03″N, 37°42′E	1499.8	13.2	27.9	60.8
Dilla	DIL	1519	sub-moist cool	06°22′N, 38°18′E	1354.6	12.9	28.1	65.0
Halaba	HAL	1772	sub-moist cool	07°18′N, 38°05′E	928.8	14.6	28.6	58.3
Hawassa	HAW	1700	sub-moist cool	07°03′5N, 38°28′E	1046.3	13.3	27.6	62.1
Kokate	KOK	1854	moist- cool	06°49′N, 37°44′′′E	1352.9	12.7	25.5	63.1

^amasl = meter above sea level, RH = relative humidity.

Source: National Meteorological Agency, Hawassa Main Branch.

Table 2. Description of sweetpotato genotypes used for the study.

No	Genotypes	Genotypes ID	Predominant flesh color		RDMC
			Code^a	Color
1	Ukrewe×Ejumula-10	G1	7	IO	31.8
2	Ukrewe×Ejumula-13	G2	7	IO	32.4
3	Ukrewe × PIPI-1	G3	2	CM	40.9
4	Ukrewe × Naspot-1	G4	2	CM	41.0
5	Ukrewe × Ogansagan-5	G5	7	IO	32.2
6	Resisto × Ejumula-7	G6	7	IO	34.1
7	Resisto × PIPI-1	G7	7	IO	31.3
8	Resisto × PIPI-2	G8	8	DO	29.1
9	Resisto × × PIPI-4	G9	2	CM	38.4
10	Resisto × PIPI-14	G10	2	CM	39.8
11	Resisto × Temesgen-10	G11	2	CM	40.2
12	Resisto × Temesgen-12	G12	7	IO	31.4
13	Resisto × Temesgen-14	G13	7	IO	31.7
14	Resisto × Temesgen-17	G14	7	IO	36.0
15	Resisto × Temesgen-23	G15	8	DO	28.9
16	Resisto × Ogansagen-5	G16	4	PY	36.8
17	Resisto × Ogansagen-16	G17	8	DO	29.7
18	Resisto × Ogansagen-20	G18	2	CM	38.4
19	Resisto × Ogansagen-23	G19	7	IO	30.5
20	Ejumula × PIPI-10	G20	7	IO	31.3
21	Ejumula × PIPI-18	G21	8	DO	26.2
22	Ejumula × PIPI-19	G22	8	DO	28.2
23	Ejumula × Temesgen-15	G23	2	CM	32.5
24	Ejumula × Ogansagen-17	G24	7	IO	30.2
25	Tula	G25	6	PO	28.5

ID = identification, IO = intermediate orange, CM = cream, DO = dark orange, PY = pale yellow, PO = pale orange, RDMC = root dry matter content.

^aThe flesh colour was coded using a scale of 1–9 as described by Huaman (1991) and (1999), where 1 = white, 2 = cream, 3 = dark cream, 4 = pale yellow, 5 = dark yellow, 6 = pale orange, 7 = intermediate orange, 8 = dark orange, 9 = strongly pigmented with anthocyanin.

Table 3. Combined analysis of variance of eight nutritional traits for 25 sweetpotato genotypes evaluated across six environments in Ethiopia during 2014 cropping season

Source of variation	df	Traits and mean squares
		β-carotene	Protein	Iron	Zinc	Starch	Fructose	Glucose	Sucrose
Environment (E)	5	23.07***	317.20***	12.18***	6.41***	371.08***	4.55***	22.46***	347.80***
Replication (R)	5	0.09ns	0.3ns	0.04ns	0.01ns	6.46*	0.18ns	0.12ns	1.73ns
Block (B)	9	0.46ns	0.10ns	0.16**	0.04ns	4.67ns	0.11ns	0.13ns	0.99ns
Genotype (G)	24	489.45***	5.90***	0.64**	0.25**	271.78***	6.08***	12.60***	108.98***
G × E	120	8.61***	4.10***	0.19**	0.12**	89.27**	5.40***	11.70***	36.80***
Error	136	0.81	0.30	0.05	0.03	2.52	0.14	0.14	0.71

df = degrees of freedom; ns = not significant, G × E = genotype by environment interaction.

*,** and *** = significant at p < 0.05, p < 0.01 and p < 0.001 probability level, respectively

Table 4. Mean performance of sweetpotato genotypes for eight nutritional traits evaluated across six environments in Ethiopia during 2014 cropping season.

Genotypes ID	Pedigree/Name	Traits
		Fresh root yield (t ha^−1)	Root dry matter (%)	β-carotene (mg 100 g^−1)	Protein (%)	Iron (mg 100 g^−1)	Zinc (mg 100 g^−1)	Starch (%)	Fructose (%)	Glucose (%)	Sucrose (%)
G1	Ukrewe × Ejumula-10	25.09	31.82	12.48	7.43	2.27	1.04	59.23	2.70	3.70	6.54
G2	Ukrewe × Ejumula-13	21.99	32.47	6.91	6.27	1.96	0.94	58.19	3.15	3.88	8.67
G3	Ukrewe × PIPI-1	21.11	37.15	0.00	5.51	1.59	0.76	64.50	3.83	4.81	3.95
G4	Ukrewe × NASPOT-1	13.94	34.84	0.00	5.52	1.62	0.86	63.19	3.36	4.23	6.54
G5	Ukrewe × Ogansagan-5	19.88	33.03	13.16	7.28	2.09	1.06	62.61	2.47	3.03	5.42
G6	Resisto × Ejumula-7	26.92	32.60	14.27	6.99	2.05	1.01	59.31	3.08	4.12	5.99
G7	Resisto × PIPI-1	22.01	29.84	13.53	6.24	1.85	0.84	57.78	3.74	4.58	12.42
G8	Resisto × PIPI-2	23.45	26.99	20.01	7.08	2.55	1.42	47.07	4.45	5.34	16.20
G9	Resisto × PIPI-4	18.29	32.59	0.00	6.84	1.84	1.01	59.03	3.70	4.16	8.81
G10	Resisto × PIPI-14	12.96	29.36	0.00	6.58	1.83	1.04	62.58	3.37	4.25	5.09
G11	Resisto × Temesgen-10	13.68	40.19	0.00	6.13	1.72	0.92	65.40	2.96	4.19	4.16
G12	Resisto × Temesgen-12	21.69	30.84	10.89	5.06	1.79	0.74	57.89	4.23	4.80	9.80
G13	Resisto × Temesgen-14	20.46	30.55	9.46	6.69	2.08	1.08	55.65	4.40	5.80	5.61
G14	Resisto × Temesgen-17	12.71	31.59	10.32	7.48	2.07	1.09	59.32	3.49	4.88	7.08
G15	Resisto × Temesgen-23	13.70	25.23	16.59	5.48	1.90	0.97	53.16	5.23	6.42	10.07
G16	Resisto × Ogansagen-5	24.19	38.23	0.00	6.44	1.81	1.00	67.95	2.04	2.62	2.71
G17	Resisto × Ogansagen-16	23.10	29.45	5.26	6.44	2.16	1.14	52.14	4.67	5.79	9.87
G18	Resisto × Ogansagen-20	20.67	36.23	0.00	7.83	2.10	1.06	64.32	2.79	3.19	4.37
G19	Resisto × Ogansagen-23	21.30	33.09	16.30	7.81	2.20	1.07	58.66	2.97	3.71	6.55
G20	Ejumula × PIPI-10	25.46	30.06	13.99	6.39	2.09	1.01	60.32	2.92	3.54	8.98
G21	Ejumula × PIPI-18	9.64	25.35	14.26	6.10	2.18	0.93	55.87	3.32	3.75	11.38
G22	Ejumula × PIPI-19	20.95	26.75	14.26	6.46	2.12	1.05	55.15	3.75	4.65	10.60
G23	Ejumula × Temesgen-15	23.80	32.91	0.00	5.73	1.64	0.87	67.37	2.58	2.74	4.67
G24	Ejumula × Ogansagen-17	21.60	30.48	11.37	6.64	2.06	1.07	60.32	2.94	3.63	5.94
G25	Tula	7.55	24.30	9.51	5.49	1.74	0.71	50.76	5.14	7.49	13.44
Mean		19.45	31.44	8.47	6.48	1.97	0.99	59.11	3.49	4.37	7.79
LSD (0.05)		3.24	2.32	0.73	0.47	0.17	0.14	1.28	0.30	0.30	0.68
CV (%)		25.64	15.4	5.50	8.90	10.97	17.27	2.69	10.78	8.59	10.81
R^2 (%)		73.2	83.4	99.20	98.03	94.06	93.14	98.33	97.82	98.99	98.98

ID = identification.

Table 5. Correlation coefficients describing pair-wise association among seven nutritional traits of sweetpotato genotypes evaluated across six environments in Ethiopia during 2014 cropping season.

Traits	Protein	Iron	Zinc	Starch	Fructose	Glucose	Sucrose
β-carotene	0.10ns	0.27***	0.14*	−0.43***	0.12*	0.12*	0.36***
Protein		0.80***	0.79***	−0.16**	−0.11ns	−0.10ns	−0.27***
Iron			0.83***	−0.45***	0.10ns	0.11ns	−0.06ns
Zinc				−0.29***	−0.01ns	0.01ns	−0.22**
Starch					−0.70***	−0.72***	−0.66***
Fructose						0.92***	0.41***
Glucose							0.38***

ns = not significant.

*,** and *** = denote significant correlations at 0.05, 0.01 and 0.001 probability levels, respectively,