Identification and selection of low-phosphate-tolerant germplasm in barley (Hordeum vulgare L.)

Figures & data

Figure 1. A cluster dendrogram of 150 barley (Hordeum vulgare L.) accessions based on the results obtained by the TOPSIS method.

Figure 2. Economical characters of two barley (Hordeum vulgare L.) genotypes under normal and low phosphorus (P) levels after harvests (A: plant height, B: stem diameter, C: spike length, D: grain number of spike, E: total spike weight, F: thousand-grain weight, G: PUE). +P: normal P level; −P: P deficiency stress. Values are mean±standard deviation from three independent biological replicates. Lower case letters represent significant differences at the levels of P = 0.05.

Table 1. Dry weight and root morphological parameters of two barley (Hordeum vulgare L.) genotypes under normal and low phosphorus (P) levels. +P: normal P level; −P: P deficiency stress. Values are mean ± standard deviation from three independent biological replicates. Lower case letters represent significant differences at the levels of P = 0.05.

	Cultivar	Treatment	Straw dry weight (g)		Root dry weight (g)		Root:shoot ratio		Total root length (cm)		Root surface area (cm^2)		Root volume (cm^3)
10d	GN121	+P	0.5271 ± 0.0001	a	0.0157 ± 0.0003	a	0.2975 ± 0.0001	a	282.7190 ± 0.1990	a	35.5860 ± 0.6612	a	0.2640 ± 0.0230	a
		−P	0.5220 ± 0.0060	a	0.0154 ± 0.0001	a	0.2950 ± 0.0003	a	281.4437 ± 1.1715	a	35.5762 ± 1.4050	a	0.2510 ± 0.0120	a
	GN42	+P	0.0246 ± 0.0007	b	0.0048 ± 0.0001	b	0.2727 ± 0.0010	b	219.7727 ± 1.1090	b	19.7790 ± 0.8362	b	0.0930 ± 0.0140	b
		−P	0.0183 ± 0.0011	c	0.0041 ± 0.0002	c	0.2530 ± 0.0063	c	212.4682 ± 1.5527	c	16.0460 ± 0.9272	c	0.0627 ± 0.0098	c
20d	GN121	+P	0.1522 ± 0.0002	a	0.0356 ± 0.0003	a	0.2339 ± 0.0009	a	395.0866 ± 0.4343	a	52.9123 ± 1.7668	a	0.5623 ± 0.0292	a
		−P	0.1518 ± 0.0005	a	0.0351 ± 0.0008	a	0.2330 ± 0.0004	a	393.4002 ± 1.5670	a	51.0871 ± 2.3416	a	0.5367 ± 0.0254	a
	GN42	+P	0.0657 ± 0.0003	b	0.0137 ± 0.0005	b	0.2085 ± 0.0007	b	332.1482 ± 1.1750	b	36.6761 ± 2.1844	b	0.2800 ± 0.0302	b
		−P	0.0504 ± 0.0010	c	0.0096 ± 0.0007	c	0.1905 ± 0.0004	c	295.6782 ± 2.6504	c	30.6068 ± 1.7799	c	0.1740 ± 0.0120	c
30d	GN121	+P	0.2312 ± 0.0002	a	0.0496 ± 0.0007	a	0.2144 ± 0.0001	a	487.5847 ± 0.6136	a	63.1498 ± 1.2455	a	0.8670 ± 0.0330	a
		−P	0.2297 ± 0.0010	a	0.0489 ± 0.0006	a	0.2132 ± 0.0003	a	483.7511 ± 2.2580	a	61.7465 ± 0.3052	a	0.8363 ± 0.0252	a
	GN42	+P	0.1195 ± 0.0100	b	0.0216 ± 0.0004	b	0.1808 ± 0.0011	b	396.8212 ± 1.8399	b	48.5102 ± 2.4700	b	0.5590 ± 0.0430	b
		−P	0.0976 ± 0.0020	c	0.0167 ± 0.0025	c	0.1710 ± 0.0007	c	347.7395 ± 2.8963	c	39.6975 ± 2.6807	c	0.3603 ± 0.0206	c

Table 2. Chlorophyll and malondialdehyde (MDA) content of two barley (Hordeum vulgare L.) genotypes under normal and low phosphorus (P) levels. +P: normal P level; −P: P deficiency stress. Values are mean ± standard deviation from three independent biological replicates. Lower case letters represent significant differences at the levels of P = 0.05. FW: fresh weight.

	Cultivar	Treatment	Chlorophyll a (mg g^−1)		Chlorophyll b (mg g^−1)		Chlorophyll a + b (mg g^−1)		MDA (μmol g^−1 FW)
30d	GN121	+P	0.8216 ± 0.0075	a	0.3298 ± 0.0033	a	1.1526 ± 0.0021	a	0.02752 ± 0.0002	a
		−P	0.8104 ± 0.0053	a	0.3208 ± 0.0048	a	1.2411 ± 0.0848	a	0.02801 ± 0.0005	a
	GN42	+P	0.6982 ± 0.0012	b	0.2865 ± 0.0051	b	0.9856 ± 0.0042	b	0.02497 ± 0.0009	a
		−P	0.5232 ± 0.0017	c	0.2421 ± 0.0055	c	0.7661 ± 0.0069	c	0.02648 ± 0.0017	a
60d	GN121	+P	0.9846 ± 0.0046	a	0.3755 ± 0.0051	a	1.3605 ± 0.0142	a	0.02273 ± 0.0002	ab
		−P	0.9713 ± 0.0013	a	0.3694 ± 0.0033	a	1.342 ± 0.0057	b	0.02319 ± 0.0001	ab
	GN42	+P	0.8136 ± 0.0085	b	0.3242 ± 0.0031	b	1.1389 ± 0.0065	c	0.02049 ± 0.0014	b
		−P	0.7565 ± 0.0042	c	0.2649 ± 0.0059	c	1.0224 ± 0.0423	d	0.02391 ± 0.0011	a
90d	GN121	+P	0.5323 ± 0.0081	a	0.2615 ± 0.0052	a	0.7947 ± 0.0125	a	0.0195 ± 0.0003	b
		−P	0.5192 ± 0.0101	a	0.2585 ± 0.0009	a	0.7785 ± 0.0096	a	0.01998 ± 0.0001	b
	GN42	+P	0.4269 ± 0.0039	b	0.2156 ± 0.0111	b	0.6432 ± 0.0051	b	0.01725 ± 0.0003	c
		−P	0.3513 ± 0.0096	c	0.1795 ± 0.0024	c	0.5313 ± 0.0103	c	0.02149 ± 0.0004	a

Table 3. Protective enzymes activities of two barley (Hordeum vulgare L.) genotypes under normal and low phosphorus (P) levels. U (unit of enzyme activity): the amount of enzyme completely reacted with 1 μmol substrate during 1 min under the standard condition. +P: normal P level; −P: P deficiency stress; SOD: superoxide dismutase; POD: peroxidase; CAT: catalase. Values are mean ± standard deviation from three independent biological replicates. Lower case letters represent significant differences at the levels of P = 0.05.

	Cultivar	Treatment	SOD (U·g^–1, FW)		POD [ΔOD470·(min·g)^–1 FW]		CAT [ΔOD240·(min·g)^–1 FW]
30d	GN121	+P	168.0383 ± 2.4127	a	223.4581 ± 2.8198	a	0.563 ± 0.0104	a
		−P	166.9126 ± 5.8139	a	221.3627 ± 3.7903	a	0.545 ± 0.0035	a
	GN42	+P	152.6666 ± 3.0309	b	214.3448 ± 1.7441	b	0.433 ± 0.0104	b
		−P	148.5921 ± 7.7856	b	205.1647 ± 1.5916	c	0.391 ± 0.0041	c
60d	GN121	+P	135.9453 ± 1.9867	a	261.9842 ± 2.6985	a	0.632 ± 0.0127	a
		−P	133.9554 ± 5.6581	a	258.3241 ± 6.7251	a	0.629 ± 0.0162	a
	GN42	+P	124.1803 ± 1.4063	b	235.6183 ± 1.4003	b	0.512 ± 0.0139	b
		−P	101.1639 ± 6.6453	c	212.7351 ± 1.7774	c	0.466 ± 0.0087	c
90d	GN121	+P	123.4513 ± 2.8568	a	211.9453 ± 6.1268	a	0.234 ± 0.0017	a
		−P	121.13 ± 2.9838	a	208.3458 ± 2.2494	a	0.226 ± 0.0046	a
	GN42	+P	104.2158 ± 1.3835	b	192.4681 ± 1.4311	b	0.178 ± 0.0023	b
		−P	91.1534 ± 1.1773	c	185.3642 ± 1.8654	c	0.126 ± 0.0069	c

Figure 3. Inorganic phosphate (Pi) concentration of two barley (Hordeum vulgare L.) genotypes under normal and low P levels. +P: normal P level; −P: P deficiency stress; PC: inorganic phosphate content; DW: dry weight. Values are mean ± standard deviation from three independent biological replicates. Lower case letters represent significant differences at the levels of P = 0.05.

Figure 4. Relative expression analysis of HvPT5 in roots by qRT-PCR (quantitative reverse transcriptase polymerase chain reaction). +P: normal P level; −P: P deficiency stress. The y-axis indicates the relative expression level of HvPT5; values are mean±standard deviation from three independent biological replicates. Lower case letters represent significant differences at the levels of P = 0.05.