Improvement of soybean seedling growth under salinity stress by biopriming of high-vigour seeds with salt-tolerant isolate of Trichoderma harzianum

Figures & data

Table 1. ANOVA showing F-ratios and significance levels of the data for germination, growth and biochemical parameters of soybean grown under three levels of salinity stress after biopriming of seed lots of different vigour with Trichoderma harzianum.

Sources of variation		Mean squares
	df	Seedling emergence percentage	Seedling emergence rate	Root length	Shoot length	Leaf greenness
Block	3	33.49^ns	0.01^ns	0.22^ns	0.93^ns	4.16*
Salinity^a (S)	2	3114.59**	0.42**	5.26**	37.65**	189.66**
Vigour^b (V)	1	6153.24**	5.02**	16.10**	245.09**	901.24**
Biopriming^c (B)	1	1061.26**	0.03^ns	2.24**	10.53**	3.31*
S × V	2	80.66^ns	0.4**	0.60^ns	6.91**	1.53^ns
S × B	2	0.91^ns	0.003^ns	1.18**	3.92**	13.14**
V × B	1	4.26^ns	0.11**	0.78^ns	0.17^ns	0.21^ns
S × V × B	2	0.91^ns	0.025^ns	1.02*	1.23^ns	7.60**
Error	33	74.09	0.01	0.21	2.99	0.67
C.V. (%)	–	15.6	10.8	10.4	11.8	18.2
Sources of variation		Root			Leaf
	df	Catalase activity	Guaiacol peroxidase activity	Proline content	Catalase activity	Guaiacol peroxidase activity	Proline content
Block	3	0.003^ns	0.058*	25.14^ns	0.0003^ns	0.0003^ns	20.66^ns
Salinity^a (S)	2	0.29**	0.3**	1915.42**	0.3**	0.2**	1345.10**
Vigour^b (V)	1	0.21**	0.2**	1712.65**	0.7**	0.1**	2348.69**
Biopriming^c (B)	1	0.4**	0.25**	5234.74**	1.0**	0.18**	3691.38**
S × V	2	0.01**	0.5**	91.84^ns	0.1**	0.005^ns	16.52^ns
S × B	2	0.09**	0.025^ns	114.24^ns	0.03**	0.005^ns	156.89*
V × B	1	0.01**	0.7**	160.47^ns	0.0005^ns	0.1**	77.35^ns
S × V × B	2	0.03**	0.05*	187.36*	0.05**	0.03*	8.82^ns
Error	33	0.005	0.01	142.12	0.01	0.009	139.74
C.V. (%)	–	16.6	12.2	16.7	14.8	14.4	17.9

Note: ns: non-significance.

^a0 (0.54 dS/m), 3, and 6 dS/m.

^bTwo seed lots with 98% and 88% viability.

^cTrichoderma harzianum isolate and unprimed (control).

*Significance at 0.05.

**Significance at 0.01.

Figure 1. Soybean seedling emergence influenced by (A) interaction of seed vigour level and salt stress and (B), interaction of seed vigour level and biopriming with Trichoderma.

Table 2. Effect of salinity, seed vigour, and biopriming with Trichoderma on soybean seedling emergence.

Treatments	Seedling emergence		Leaf proline content
	%	% Reduction	(μmol g^−1 FW)	% Increase
Salinity effect
No stress	69.0^a	–
3 dS/m	55.2^b	20.0
6 dS/m	41.1^c	25.5
S.E. of mean	2.152
Seed vigour effect
High vigour (98% germination)	66.4^a	–	58.75^b	–
Low vigour (88% germination)	43.8^b	34.0	72.74^a	23.8
S.E. of mean	1.757		1.287
Biopriming with Trichoderma effect
Primed	69.8^a	–
Unprimed	60.4^b	13.5
S.E. of mean	1.757

Note: The interactions between experimental factors were not significant, so means are presented for main effects of salinity, seed vigour, and biopriming with Trichoderma on seedling emergence and the main effect of seed vigour on leaf proline content.

Figure 2. Root length of soybean seedling influenced by seed vigour level and biopriming with Trichoderma under salt stress.

Figure 3. Shoot length of soybean seedling influenced by (A), interaction of seed vigour level and salt stress and (B) interaction of biopriming with Trichoderma and salt stress.

Figure 4. Leaf greenness of soybean seedling influenced by seed vigour level and biopriming with Trichoderma under salt stress.

Figure 5. (A) Root proline content of soybean seedling influenced by seed vigour level and biopriming with Trichoderma under salt stress. (B) Leaf proline content of soybean seedling influenced by interaction of biopriming with Trichoderma and salt stress.

Figure 6. (A) Root and (B) Leaf catalase activity influenced by seed vigour level and biopriming with Trichoderma under salt stress.

Figure 7. (A) Root and (B) Leaf guaiacol peroxidase activity influenced by seed vigour level and biopriming with Trichoderma under salt stress.