**3. Results**

#### **3.1 First experiment: Action of cruiser on the germination of soybean seeds**

In the cultivar BRS 133 the treatment with Cruiser used in the recommended level (D1) and at twice the recommended level (D2) accelerated the germination in the first 24 h of imbibition (Figure 1). The increase in germination was higher at D2 treatment.

In the cultivar Pintado (Figure 2) Cruiser caused acceleration of germination until 36 h of imbibition, being observed that at 24 h of imbibition the increase in germination was higher at the twice-recommended level of Cruiser and at 36 hours of imbibition, germination did not differ statistically between the two levels of Cruiser. Germination in both cultivars did not differ significantly between the control seeds (D0) and seeds treated with two levels of Cruiser (D1 and D2) between 48 and 72 h of imbibition.

Fig. 1. Soybean germination percentage cv. BRS 133 treated at recommended dose of Cruiser (D1), double of recommended dose (D2) and check (D0). Average followed by the same letter did not differ significantly for each imbibition period. **ns**: not differ significantly for each imbibition period.

For each treatment and imbibition period described in Table 1, were collected samples of embryo axis in two imbibition periods to determine activity of the antioxidant enzymes,

Enzymatic extracts used for determination of SOD and POD activities were obtained according to the method described by Ekler et al. 1993. POD and SOD activities were assayed according to the method described by Teisseire & Guy (2000) e Bor et al. (2003),

In the cultivar BRS 133 the treatment with Cruiser used in the recommended level (D1) and at twice the recommended level (D2) accelerated the germination in the first 24 h of

In the cultivar Pintado (Figure 2) Cruiser caused acceleration of germination until 36 h of imbibition, being observed that at 24 h of imbibition the increase in germination was higher at the twice-recommended level of Cruiser and at 36 hours of imbibition, germination did not differ statistically between the two levels of Cruiser. Germination in both cultivars did not differ significantly between the control seeds (D0) and seeds treated with two levels of

**cv. BRS133 Control**

**ns ns ns ns**

**24 36 48 60 72**

D1 - 100 mL Cruiser/100 kg seeds D2 - 200 mL Cruiser/100 kg seeds

**Hours of imbibition**

D0 - Check with water

Fig. 1. Soybean germination percentage cv. BRS 133 treated at recommended dose of Cruiser (D1), double of recommended dose (D2) and check (D0). Average followed by the same letter did not differ significantly for each imbibition period. **ns**: not differ significantly for

**3.1 First experiment: Action of cruiser on the germination of soybean seeds** 

imbibition (Figure 1). The increase in germination was higher at D2 treatment.

peroxidase (POD) and superoxide dismutase (SOD).

Cruiser (D1 and D2) between 48 and 72 h of imbibition.

**a b c**

respectively.

**3. Results** 

**0**

Tukey α=0.01

each imbibition period.

**20**

**40**

**Seed germination (%)**

**60**

**80**

**100**

Fig. 2. Soybean germination percentage cv. Pintado treated at recommended dose of Cruiser (D1), double of recommended dose (D2) and check (D0). Average followed by the same letter did not differ significantly for each imbibition period. **ns**: not differ significantly for each imbibition period.

#### **3.2 Second Experiment: Cruiser action on the germination of soybean seeds subjected to stress conditions induced by heavy metal (aluminum), salinity (NaCl) and water deficit**

In the presence of aluminum in different concentrations (Figures 3 to 5), the treatment of soybean seeds of cultivar BRS 133 with the recommended level of Cruiser (D1) caused acceleration of germination, when compared with the control (D0), up to 36 h of imbibition. In the soybean seeds of cultivar Pintado, the same pattern of cultivar BRS 133 was observed within 36 h of imbibition in aluminum concentration of 5 mmol L-1 (Figure 3) and up to 48 h of soaking in aluminum concentrations of 10 and 15 mmol L-1 (Figures 4 and 5, respectively). In the Figure 6 is shown comparisons of the effect of Cruiser on the germination of cultivar BRS 133 in the different concentrations of aluminum, at 24 and 36 h of imbibition. In the cultivar Pintado comparisons were performed at 36 and 48 h of imbibition (Figure 7).

Analyzing the results can be considered that: a) aluminum delays germination in both cultivars studied; b) in the two soybean cultivars, the increase in aluminum concentration caused a decrease in germination; c) Cruiser increase germination in aluminum stress conditions and d) on cultivar BRS 133 at 36 h of imbibition (Figure 6) and on cultivar Pintado at 48 h of imbibition (Figure 7) greater the stress by the presence of aluminum, greater was the effect of Cruiser. Therefore, the results of soybean germination in response to treatment of seeds with Cruiser, under stressful aluminum conditions, indicate that the insecticide acts by reducing the toxic effect of aluminum on germination.

Fig. 3. Soybean germination percentage cv. BRS 133 and cv. Pintado treated at recommended dose of Cruiser (D1) and check (D0), under aluminum sulfate 5 mmol L-1. Average followed by the same letter did not differ significantly for each imbibition period. **ns**: not differ significantly for each imbibition period.

**cv. BRS133 Al 5 mmol L-1**

**ns ns ns**

**ns ns**

**a**

**b**

**24 36 48 60 72**

**Hours of imbibition**

D1 - 100 mL Cruiser/100 kg seeds

**24 36 48 60 72**

**Hours of imbibition**

D1 - 100 mL Cruiser/100 kg seeds

D0 - Check with water

recommended dose of Cruiser (D1) and check (D0), under aluminum sulfate 5 mmol L-1. Average followed by the same letter did not differ significantly for each imbibition period.

**a**

Fig. 3. Soybean germination percentage cv. BRS 133 and cv. Pintado treated at

**b**

D0 - Check with water

**cv. Pintado Al 5 mmol L-1**

**ns**

**0**

**0**

Tukey α=0.01

**ns**: not differ significantly for each imbibition period.

**ns**

**20**

**40**

**Seed germination (%)**

**60**

**80**

**100**

Tukey α=0.01

**ns**

**20**

**40**

**Seed germination (%)**

**60**

**80**

Fig. 4. Soybean germination percentage cv. BRS 133 and cv. Pintado treated at recommended dose of Cruiser (D1) and check (D0), under aluminum sulfate 10 mmol L-1. Average followed by the same letter did not differ significantly for each imbibition period. **ns**: not differ significantly for each imbibition period.

Fig. 5. Soybean germination percentage cv. BRS 133 and cv. Pintado treated at recommended dose of Cruiser (D1) and check (D0), under aluminum sulfate 15 mmol L-1. Average followed by the same letter did not differ significantly for each imbibition period. **ns**: not differ significantly for each imbibition period.

**cv. BRS133 Al 15 mmol L-1**

**ns ns ns**

**a**

**b**

**24 36 48 60 72**

**Hours of imbibition**

D1 - 100 mL Cruiser/100 kg seeds

**a**

**ns**

**ns**

**24 36 48 60 72**

**Hours of imbibition**

D1 - 100 mL Cruiser/100 kg seeds

D0 - Check with water

recommended dose of Cruiser (D1) and check (D0), under aluminum sulfate 15 mmol L-1. Average followed by the same letter did not differ significantly for each imbibition period.

**a**

Fig. 5. Soybean germination percentage cv. BRS 133 and cv. Pintado treated at

**ns b**

**ns**: not differ significantly for each imbibition period.

D0 - Check with water

**cv. Pintado Al 15 mmol L-1**

**b**

**0**

**0**

Tukey α=0.01

**20**

**40**

**Seed germination (%)**

**60**

**80**

**100**

Tukey α=0.01

**ns**

**20**

**40**

**Seed germination (%)**

**60**

**80**

**100**

Under salinity conditions in the presence of NaCl (Figures 8 to 11), the treatment of soybean seeds of cultivar BRS 133 with Cruiser caused acceleration of germination in the first periods of imbibition evaluated. It was observed that higher the concentration of NaCl, the effect mentioned was observed in the later periods of imbibition, reaching up to 48 h in NaCl concentration of 150 mmol L-1 (Figure 11). It was observed that Cruiser had no effect on germination of cultivar Pintado at concentrations of NaCl 25 (Figure 8) and 100 mmol L-1 (Figure 10). In NaCl concentration of 50 mmol L-1 (Figure 9) Cruiser decreased germination, but in the concentration of 150 mmol L-1 (Figure 11) it increased germination at 48 h of imbibition.

Comparing the results of Cruiser effect on germination of cultivar BRS 133 in the different concentrations of NaCl in the imbibition periods of 24, 36 and 48 h (Figure 12), can be made several considerations: a) NaCl causes decrease in germination, the effect being more pronounced greater the salinity stress; b) at 24 h of imbibition, Cruiser had effect until the NaCl concentration of 100 mmol.L-1; c) at 36 h of imbibition, Cruiser eliminated the effect of salt stress up to the salt concentration of 50 mmol.L-1 and in higher salinity stress, greater was the effect of Cruiser; d) at 48 h of imbibition, Cruiser eliminated any effect of salt stress. Analyzing the comparisons of the results in Figure13 can be considered that in cultivar Pintado

Cruiser had no effect on germination under salt stress, during imbibition of 24, 36 and 48 h. The effect of Cruiser on germination of cultivar BRS 133 under water deficit induced by PEG solutions of different water potentials are shown in Figures 14 to 16. At the water potentials of -0.1 and -0.2 MPa, Cruiser had no effect on germination, but at the water potential of -0.3 MPa, Cruiser has caused a significant increase in germination at 72 h of imbibition. In respect of germination of cultivar Pintado under water deficit conditions induced by PEG solutions of different water potentials, it was observed that in the water potential of -0.1 MPa, Cruiser caused increase on germination at 48 and 60 h of imbibition. In water potential of -0.2 MPa the increase on germination by Cruiser effect were observed from 60 to 84 h of imbibition and in the potential of -0.3 MPa only at 72 and 84 h of imbibition.

Comparing the results of the effect of Cruiser on germination of cultivar BRS 133 at different imbibition periods (Figure 17) in the different water potentials, can be made some considerations: a) the decrease of water potential delays germination; b) there is consistency of Cruiser effect in increasing the germination for the three water potentials; c) at 72 h of imbibition, the largest increase in germination under Cruiser effect occurred where the water deficit was higher.

Comparing the effects of Cruiser on germination of cultivar Pintado, at the water potentials used (Figure 18), can be made some considerations: a) water deficiency causes delayed germination; b) Cruiser has effect in combating water stress for all the three tested water potentials; c) at 72 and 84 h of imbibition Cruiser has a greater effect on germination in the largest water deficit.

In Figure 19 is represented, the effect of Cruiser on the weights of embryo axis of soybean cultivars BRS 133 and Pintado under conditions of aluminum presence. Can be inferred that in all concentrations of aluminum used Cruiser has caused increased growth of the embryo axis but, this increase was significantly higher in the absence of aluminum, in the concentration of 10 mmol L-1 for BRS 133 and in the absence of aluminum (0 mmol L-1) to cultivar Pintado. The effect of Cruiser on development of embryo axis occurred in the absence of aluminum in both cultivars. The weight of the embryo axis tended to be equal between the treated and untreated seeds with Cruiser, with the increase of aluminum stress (Figures 57 and 58).

Fig. 6. Comparison of soybean germination percentage cv. BRS 133 treated at recommended dose of Cruiser (D1) and check (D0), under different aluminum sulfate concentrations (5, 10 and 15 mmol L-1) at 24 and 36 h of imbibition.

**cv. BRS133 Al 24 h**

D0: y = 0,08x2 - 1,92x + 10,9 R² = 0,9975

D1: y = 0,09x2 - 2,89x + 28,05 R² = 0,8064

**0 5 10 15**

**Concentration of Al sulfate (mmol.L-1)**

**0 5 10 15**

**Concentration of Al sulfate (mmol.L-1)**

D0 - Check with water D1 - 100 mL Cruiser/100 kg seeds

Fig. 6. Comparison of soybean germination percentage cv. BRS 133 treated at recommended dose of Cruiser (D1) and check (D0), under different aluminum sulfate concentrations (5, 10

D0: y = 0,32x2 - 7,88x + 96,6 R² = 0,995

D1: y = 0,31x2 - 5,43x + 96,35 R² = 0,9923

D0 - Check with water D1 - 100 mL Cruiser/100 kg seeds

**cv. BRS133 Al 36 h**

**-20**

**-20**

and 15 mmol L-1) at 24 and 36 h of imbibition.

**0**

**20**

**40**

**Seed germination (%)**

**60**

**80**

**100**

**0**

**20**

**40**

**Seed germination (%)**

**60**

**80**

Fig. 7. Comparison of soybean germination percentage cv. Pintado treated at recommended dose of Cruiser (D1) and check (D0), under different aluminum sulfate concentrations (5, 10 and 15 mmol L-1) at 24 and 36 h of imbibition.

Fig. 8. Soybean germination percentage cv. BRS 133 and cv. Pintado treated at recommended dose of Cruiser (D1) and check (D0), under NaCl 25 mmol L-1. Average followed by the same letter did not differ significantly for each imbibition period. **ns**: not differ significantly for each imbibition period.

**cv. BRS133 NaCl 25 mmol L-1**

**ns ns ns ns**

**24 36 48 60 72**

**Hours of imbibition**

D1 - 100 mL Cruiser/100 kg seeds

**ns ns**

**24 36 48 60 72**

**Hours of imbibition**

D1 - 100 mL Cruiser/100 kg seeds

D0 - Check with water

Fig. 8. Soybean germination percentage cv. BRS 133 and cv. Pintado treated at

recommended dose of Cruiser (D1) and check (D0), under NaCl 25 mmol L-1. Average followed by the same letter did not differ significantly for each imbibition period. **ns**: not

D0 - Check with water

**cv. Pintado NaCl 25 mmol L-1**

**ns**

**ns**

**0**

**0**

Tukey α=0.01

differ significantly for each imbibition period.

**ns**

**20**

**40**

**Seed germination (%)**

**60**

**80**

**100**

Tukey α=0.01

**b**

**a**

**20**

**40**

**Seed germination (%)**

**60**

**80**

Fig. 9. Soybean germination percentage cv. BRS 133 and cv. Pintado treated at recommended dose of Cruiser (D1) and check (D0), under NaCl 50 mmol L-1. Average followed by the same letter did not differ significantly for each imbibition period. **ns**: not differ significantly for each imbibition period.

Fig. 10. Soybean germination percentage cv. BRS 133 and cv. Pintado treated at recommended dose of Cruiser (D1) and check (D0), under NaCl 100 mmol L-1. Average followed by the same letter did not differ significantly for each imbibition period. **ns**: not differ significantly for each imbibition period.

**cv. BRS133 NaCl 100 mmol L-1**

**ns ns ns**

**ns ns**

**b**

**a**

**24 36 48 60 72**

**Hours of imbibition**

D1 - 100 mL Cruiser/100 kg seeds

**24 36 48 60 72**

**Hours of imbibition**

D1 - 100 mL Cruiser/100 kg seeds

D0 - Check with water

Fig. 10. Soybean germination percentage cv. BRS 133 and cv. Pintado treated at

recommended dose of Cruiser (D1) and check (D0), under NaCl 100 mmol L-1. Average followed by the same letter did not differ significantly for each imbibition period. **ns**: not

**a b**

D0 - Check with water

**cv. Pintado NaCl 100 mmol L-1**

**ns**

**0**

**0**

Tukey α=0.01

differ significantly for each imbibition period.

**ns**

**20**

**40**

**Seed germination (%)**

**60**

**80**

**100**

Tukey α=0.01

**ns**

**20**

**40**

**Seed germination (%)**

**60**

**80**

Fig. 11. Soybean germination percentage cv. BRS 133 and cv. Pintado treated at recommended dose of Cruiser (D1) and check (D0), under NaCl 150 mmol L-1. Average followed by the same letter did not differ significantly for each imbibition period. **ns**: not differ significantly for each imbibition period.

**cv. BRS133 NaCl 24 h**

D0: y = 0,0012x2 - 0,2301x + 8,6663 R² = 0,7348 D1: y = 0,0015x2 - 0,4171x + 28,929 R² = 0,9602

**0 25 50 75 100 125 150**

**Concentration of NaCl (mmol.L-1)**

D0 - Check with water D1 - 100 mL Cruiser/100 kg seeds

**cv. BRS133 NaCl 36 h**

D0: y = -0,0029x2 - 0,0406x + 94,581 R² = 0,9632

D1: y = -0,0021x2 + 0,1168x + 96,695 R² = 0,9956

**0 25 50 75 100 125 150**

**Concentration of NaCl (mmol.L-1)**

D0 - Check with water D1 - 100 mL Cruiser/100 kg seeds

**-20**

**-20**

**0**

**20**

**40**

**Seed germination (%)**

**60**

**80**

**100**

**0**

**20**

**40**

**Seed germination (%)**

**60**

**80**

Fig. 12. Comparison of soybean germination percentage cv. BRS133 treated at recommended dose of Cruiser (D1) and check (D0), under different NaCl concentrations (25, 50, 100 and 150 mmol L-1) at 24, 36 and 48 h of imbibition.

Fig. 13. Comparison of soybean germination percentage cv. Pintado treated at recommended dose of Cruiser (D1) and check (D0), under different NaCl concentrations (25, 50, 100 and 150 mmol L-1) at 24, 36 and 48 h of imbibition.

**cv. Pintado NaCl 36 h**

**-20**

**-20**

**0**

**20**

**40**

**Seed germination (%)**

**60**

**80**

**100**

**0**

**20**

**40**

**Seed germination (%)**

**60**

**80**

**100**

D0: y = 0,0005x2 - 0,6086x + 79,339 R² = 0,9812 D1: y = 0,0034x2 - 1,0637x + 91,693 R² = 0,9116

**0 25 50 75 100 125 150**

**Concentration of NaCl (mmol.L-1)**

D0 - Check with water D1 - 100 mL Cruiser/100 kg seeds

**cv. Pintado NaCl 48 h**

D0: y = -0,0049x2 + 0,2332x + 90,18 R² = 0,9913 D1: y = -0,0027x2 - 0,0069x + 94,388 R² = 0,9484

**0 25 50 75 100 125 150**

**Concentration of NaCl (mmol.L-1)**

D0 - Check with water D1 - 100 mL Cruiser/100 kg seeds

recommended dose of Cruiser (D1) and check (D0), under different NaCl concentrations (25,

Fig. 13. Comparison of soybean germination percentage cv. Pintado treated at

50, 100 and 150 mmol L-1) at 24, 36 and 48 h of imbibition.

Fig. 14. Soybean germination percentage cv. BRS 133 and cv. Pintado treated at recommended dose of Cruiser (D1) and check (D0), under PEG potential -0,1 MPa. Average followed by the same letter did not differ significantly for each imbibition period. **ns**: not differ significantly for each imbibition period.

Fig. 15. Soybean germination percentage cv. BRS 133 and cv. Pintado treated at recommended dose of Cruiser (D1) and check (D0), under PEG potential -0,2 MPa. Average followed by the same letter did not differ significantly for each imbibition period. **ns**: not differ significantly for each imbibition period.

**cv. BRS133 PEG -0,2 MPa**

**ns**

**ns**

**ns ns**

**a**

**b**

**a**

**b**

**24 36 48 60 72 84**

**Hours of imbibition**

D1 - 100 mL Cruiser/100 kg seeds

**24 36 48 60 72 84**

**b**

**a**

**Hours of imbibition**

D1 - 100 mL Cruiser/100 kg seeds

D0 - Check with water

recommended dose of Cruiser (D1) and check (D0), under PEG potential -0,2 MPa. Average followed by the same letter did not differ significantly for each imbibition period. **ns**: not

Fig. 15. Soybean germination percentage cv. BRS 133 and cv. Pintado treated at

**ns**

D0 - Check with water

**cv. Pintado PEG -0,2 MPa**

**0**

**0**

**20**

**40**

**Seed germination (%)**

**60**

**80**

**100**

Tukey α=0.01

**ns ns**

**ns ns**

Tukey α=0.01

differ significantly for each imbibition period.

**20**

**40**

**Seed germination (%)**

**60**

**80**

Fig. 16. Soybean germination percentage cv. BRS 133 and cv. Pintado treated at recommended dose of Cruiser (D1) and check (D0), under PEG potential -0.3 MPa. Average followed by the same letter did not differ significantly for each imbibition period. **ns**: not differ significantly for each imbibition period.

**cv. BRS133 PEG 24 h**

D0: y = 275x2 - 115,5x + 10,45 R² = 0,9333

D1: y = 750x2 - 315x + 28,5 R² = 0,9333

**0 0,1 0,2 0,3**

**Potential of PEG (MPa-1)**

D0 - Check with water D1 - 100 mL Cruiser/100 kg seeds

D0: y = 1625x2 - 804,5x + 95,55 R² = 0,9993

**cv. BRS133 PEG 36 h**

D1: y = 1800x2 - 850x + 94,5 R² = 0,9927

**0 0,1 0,2 0,3**

**Potential of PEG (MPa-1)**

D0 - Check with water D1 - 100 mL Cruiser/100 kg seeds

**-20**

**-20**

**0**

**20**

**40**

**Seed germination (%)**

**60**

**80**

**100**

**0**

**20**

**40**

**Seed germination (%)**

**60**

**80**

Fig. 17. Comparison of soybean germination percentage cv. BRS133 treated at recommended dose of Cruiser (D1) and check (D0), under different PEG potentials (-0,1; -0,2 and -0,3 MPa) at 24, 36, 48, 60, 72 and 84 h of imbibition.

**cv. BRS133 PEG 72 h**

D0: y = -875x2 + 149,5x + 96,45 R² = 0,9516 D1: y = -525x2 + 92,5x + 97,25 R² = 0,9662

**0 0,1 0,2 0,3**

**Potential of PEG (MPa-1)**

D0 - Check with water D1 - 100 mL Cruiser/100 kg seeds

**cv. BRS133 PEG 84 h**

D0: y = -700x2 + 130x + 96,5 R² = 0,9198

D1: y = -450x2 + 89x + 97,4 R² = 0,9629

**0 0,1 0,2 0,3**

**Potential of PEG (MPa-1)**

D0 - Check with water D1 - 100 mL Cruiser/100 kg seeds

Fig. 17. Comparison of soybean germination percentage cv. BRS133 treated at recommended dose of Cruiser (D1) and check (D0), under different PEG potentials (-0,1; -0,2 and -0,3 MPa)

**-20**

**-20**

at 24, 36, 48, 60, 72 and 84 h of imbibition.

**0**

**20**

**40**

**Seed germination (%)**

**60**

**80**

**100**

**0**

**20**

**40**

**Seed germination (%)**

**60**

**80**

**cv. Pintado PEG 48 h**

**0 0,1 0,2 0,3**

**Potential of PEG (MPa-1)**

**0 0,1 0,2 0,3**

**Potential of PEG (MPa-1)**

D0 - Check with water D1 - 100 mL Cruiser/100 kg seeds

D0 - Check with water D1 - 100 mL Cruiser/100 kg seeds

**cv. Pintado PEG 60 h**

D0: y = 925x2 - 592,5x + 95,25 R² = 0,9998

**-20**

**-20**

**0**

**20**

**40**

**Seed germination (%)**

**60**

**80**

**100**

**0**

**20**

**40**

**Seed germination (%)**

**60**

**80**

**100**

D0: y = 1875x2 - 855,5x + 89,95 R² = 0,9855

D1: y = 775x2 - 583,5x + 102,15 R² = 0,9699

> D1: y = -125x2 - 305,5x + 103,95 R² = 0,9497

Fig. 18. Comparison of soybean germination percentage cv. Pintado treated at recommended dose of Cruiser (D1) and check (D0), under different PEG potentials (-0,1; -0,2 and -0,3 MPa) at 24, 36, 48, 60, 72 and 84 h of imbibition.

Fig. 19. Weight (g) of embryo axis of soybean seeds cv. BRS 133 and cv. Pintado treated at recommended dose of Cruiser (D1) and check (D0), under different Al concentrations at 72 h of imbibition. Average followed by the same letter did not differ significantly for each concentration or each potential. **ns**: not differ significantly for each imbibition period.

The weights of embryo axis of soybean cultivars BRS 133 and Pintado under salinity are shown, respectively, in Figure 20. In the cultivar BRS 133 Cruiser, generally, caused an increase in the weight of embryo axis at all concentrations of NaCl used except at a concentration of 100 mmol L-1 where there was no significant difference between seeds treated and untreated. In cultivar Pintado was observed a significant increase in the weight of embryo axis in the absence of NaCl and at concentration of 25 mmol L-1; however, at the

**cv. BRS 133 Al 72 h**

**ns**

**0 5 10 15**

**a**

**ns ns**

**b**

**ns**

**Concentration of Al sulfate (mmol.L-1)**

**0 5 10 15**

**Concentration of Al sulfate (mmol.L-1)**

D0 - Check with water D1 - 100 mL Cruiser/100 kg seeds

Fig. 19. Weight (g) of embryo axis of soybean seeds cv. BRS 133 and cv. Pintado treated at recommended dose of Cruiser (D1) and check (D0), under different Al concentrations at 72 h of imbibition. Average followed by the same letter did not differ significantly for each concentration or each potential. **ns**: not differ significantly for each imbibition period.

The weights of embryo axis of soybean cultivars BRS 133 and Pintado under salinity are shown, respectively, in Figure 20. In the cultivar BRS 133 Cruiser, generally, caused an increase in the weight of embryo axis at all concentrations of NaCl used except at a concentration of 100 mmol L-1 where there was no significant difference between seeds treated and untreated. In cultivar Pintado was observed a significant increase in the weight of embryo axis in the absence of NaCl and at concentration of 25 mmol L-1; however, at the

D0 - Check with water D1 - 100 mL Cruiser/100 kg seeds

**cv. Pintado 133 Al 72 h**

**ns**

**0 0,5 1 1,5 2 2,5 3**

**0 0,5 1 1,5 2 2,5 3**

Tukey α=0.01

**Weight of embryo axis (g)**

Tukey α=0.01

**a**

**a**

**b**

**b**

**Weight of embryo axis (g)**

Fig. 20. Weight (g) of embryo axis of soybean seeds cv. BRS 133 and cv. Pintado treated at recommended dose of Cruiser (D1) and check (D0), under different and NaCl concentrations at 72 h of imbibition. Average followed by the same letter did not differ significantly for each concentration or each potential. **ns**: not differ significantly for each imbibition period.

concentration of 100 mmol L-1 Cruiser caused a decrease in axis weight. In saline conditions, Cruiser's effect on the development of the axis in cultivar BRS 133 is smaller with the increase of salt stress and in cultivar Pintado Cruiser has no effect under these conditions. The effect of Cruiser on weight of the embryo axis of cultivars BRS 133 and Pintado under water stress conditions are represented in Figure 21. It was observed that in both cultivars, Cruiser increased the development of the embryo axis in the water potentials of 0 and -0.1 MPa. In situations of greater water deficit (-0.2 and -0.3 MPa) there was no significant difference between treated and untreated seeds. The effect of Cruiser on the development of embryo axis in conditions of water stress is smaller with increasing of water deficit.

Fig. 21. Weight (g) of embryo axis of soybean seeds cv. BRS 133 and cv. Pintado treated at recommended dose of Cruiser (D1) and check (D0), under different PEG potentials at 84 h of imbibition. Average followed by the same letter did not differ significantly for each concentration or each potential. **ns**: not differ significantly for each imbibition period.

#### **3.3 Third experiment: Cruiser's action on the enzymes involved in the response to oxidative stress induced by aluminum presence, salinity and water deficit**

260 Soybean Physiology and Biochemistry

Cruiser increased the development of the embryo axis in the water potentials of 0 and -0.1 MPa. In situations of greater water deficit (-0.2 and -0.3 MPa) there was no significant difference between treated and untreated seeds. The effect of Cruiser on the development of

**cv. BRS 133 PEG 84 h**

**a**

**b**

**0 0,1 0,2 0,3**

**ns**

**ns**

**ns**

**Concentration of PEG (MPa-1)**

**0 0,1 0,2 0,3**

**ns**

**Concentration of PEG (MPa-1)**

D0 - Check with water D1 - 100 mL Cruiser/100 kg seeds

Fig. 21. Weight (g) of embryo axis of soybean seeds cv. BRS 133 and cv. Pintado treated at recommended dose of Cruiser (D1) and check (D0), under different PEG potentials at 84 h of

imbibition. Average followed by the same letter did not differ significantly for each concentration or each potential. **ns**: not differ significantly for each imbibition period.

D0 - Check with water D1 - 100 mL Cruiser/100 kg seeds

**cv. Pintado PEG 84 h**

**a**

**b**

embryo axis in conditions of water stress is smaller with increasing of water deficit.

**0**

**0**

Tukey α=0.01

**0,5**

**1**

**1,5**

**Weight of embryo axis (g)**

**2**

**2,5**

**3**

Tukey α=0.01

**0,5**

**1**

**1,5**

**Weight of embryo axis (g)**

**2**

**2,5**

**3**

**a**

**a**

**b**

**b**

Cruiser has caused significant increase in peroxidase activity (POD) in BRS 133 and Pintado cultivars at 24 and 36 h of imbibition (Figure 22) when seeds were placed to germinate in distilled water (control).

Fig. 22. Peroxidase activity (nmol purpurogalin mg protein-1 min-1) in soybean seeds cv. BRS133 and Pintado treated at recommended dose of Cruiser (D1) and check (D0), under distilled water (control). Average followed by the same letter did not differ significantly for each imbibition period. **ns**: not differ significantly for each imbibition period.

In the cultivar BRS 133 Cruiser has caused increase in POD activity at the aluminum concentration of 10 mmol L-1 (Figure 23) in the two imbibition periods analyzed, at 24 and 36 h. In the cultivar Pintado, Cruiser caused a decrease in POD activity at 36 h of imbibition and increased at 48 h.

Fig. 23. Peroxidase activity (nmol purpurogalin mg protein-1 min-1) in soybean seeds cv. BRS133 and Pintado treated at recommended dose of Cruiser (D1) and check (D0), under aluminum. Average followed by the same letter did not differ significantly for each imbibition period.

In the cultivar BRS 133 Cruiser has caused increase in POD activity at the aluminum concentration of 10 mmol L-1 (Figure 23) in the two imbibition periods analyzed, at 24 and 36 h. In the cultivar Pintado, Cruiser caused a decrease in POD activity at 36 h of imbibition

**POD cv. BRS133 Al 10 mmol L-1**

**a**

**a**

**b**

**b**

**24 36**

**36 48**

**Periods of imbibition (h)**

D0 - Check with water D1 - 100 mL Cruiser/100 kg seeds

Fig. 23. Peroxidase activity (nmol purpurogalin mg protein-1 min-1) in soybean seeds cv. BRS133 and Pintado treated at recommended dose of Cruiser (D1) and check (D0), under aluminum. Average followed by the same letter did not differ significantly for each

**Periods of imbibition (h)**

**a**

**b**

**b**

**a**

D0 - Check with water D1 - 100 mL Cruiser/100 kg seeds

**POD cv. Pintado Al 10 mmol L-1**

and increased at 48 h.

**nnol purpurogalin/**

**mg protein/min**

**0**

Tukey α=0.01

**0**

Tukey α=0.01

**150**

**300**

**nnol purpurogalin/**

imbibition period.

**mg protein/min**

**450**

**150**

**300**

**450**

In NaCl concentration of 50 mmol L-1, Cruiser caused increase of POD at 36 hours of imbibition in the cultivar BRS 133 (Figure 24). Cruiser used under conditions of NaCl concentration of 100 mmol L-1 in the cultivar Pintado caused a increase in POD activity at 36 h of imbibition and decreased enzyme activity at 48 h of imbibition.

Fig. 24. Peroxidase activity (nmol purpurogalin mg protein-1 min-1) in soybean seeds cv. BRS133 and Pintado treated at recommended dose of Cruiser (D1) and check (D0), under NaCl. Average followed by the same letter did not differ significantly for each imbibition period. **ns**: not differ significantly for each imbibition period.

Under water deficit conditions of -0.3 MPa, Cruiser increased activity of POD at 60 and 72 h of imbibition in cultivar BRS 133 (Figure 25), however, in the cultivar Pintado decreased it at 72 h of imbibition and did not alter the enzyme activity at 84 h of imbibition.

Fig. 25. Peroxidase activity (nmol purpurogalin mg protein-1 min-1) in soybean seeds cv. BRS133 and Pintado treated at recommended dose of Cruiser (D1) and check (D0), under PEG. Average followed by the same letter did not differ significantly for each imbibition period. **ns**: not differ significantly for each imbibition period.

Under water deficit conditions of -0.3 MPa, Cruiser increased activity of POD at 60 and 72 h of imbibition in cultivar BRS 133 (Figure 25), however, in the cultivar Pintado decreased it at

**POD cv. BRS133 PEG -0,3 MPa**

**60 72**

**72 84**

**Periods of imbibition (h)**

D0 - Check with water D1 - 100 mL Cruiser/100 kg seeds

Fig. 25. Peroxidase activity (nmol purpurogalin mg protein-1 min-1) in soybean seeds cv. BRS133 and Pintado treated at recommended dose of Cruiser (D1) and check (D0), under PEG. Average followed by the same letter did not differ significantly for each imbibition

**a**

**ns**

**b**

**Periods of imbibition (h)**

D0 - Check with water D1 - 100 mL Cruiser/100 kg seeds

**POD cv. Pintado PEG -0,3 MPa**

72 h of imbibition and did not alter the enzyme activity at 84 h of imbibition.

**a**

**b**

**a**

period. **ns**: not differ significantly for each imbibition period.

**b**

**0**

Tukey α=0.01

**0**

Tukey α=0.01

**150**

**300**

**nnol purpurogalin/**

**mg protein/min**

**450**

**150**

**300**

**nnol purpurogalin/**

**mg protein/min**

**450**

Regarding the activity of superoxide dismutase (SOD) (Figures 26 to 29), this did not change as effect of Cruiser when the soybean seeds of both cultivars were germinated under the same conditions of stress, the same imbibition periods analyzed to determine the POD.

Fig. 26. Superoxide dismutase activity (U mg proteína-1) in soybean seeds cv. BRS133 and Pintado treated at recommended dose of Cruiser (D1) and check (D0), under distilled water (control). **ns**: not differ significantly for each imbibition period.

Fig. 27. Superoxide dismutase activity (U mg proteína-1) in soybean seeds cv. BRS133 and Pintado treated at recommended dose of Cruiser (D1) and check (D0), under aluminum. **ns**: not differ significantly for each imbibition period.

**ns ns**

**SOD cv. BRS133 Al 10 mmol L-1**

**24 36**

**Periods of imbibition (h)**

D0 - Check with water D1 - 100 mL Cruiser/100 kg seeds

**SOD cv. Pintado Al mmol L-1**

**ns ns**

**36 48**

**Periods of imbibition (h)**

D0 - Check with water D1 - 100 mL Cruiser/100 kg seeds

Fig. 27. Superoxide dismutase activity (U mg proteína-1) in soybean seeds cv. BRS133 and Pintado treated at recommended dose of Cruiser (D1) and check (D0), under aluminum. **ns**:

Tukey α=0.01

not differ significantly for each imbibition period.

**U/mg protein**

Tukey α=0.01

**U/mg protein**

Fig. 28. Superoxide dismutase activity (U mg proteína-1) in soybean seeds cv. BRS133 and Pintado treated at recommended dose of Cruiser (D1) and check (D0), under NaCl. **ns**: not differ significantly for each imbibition period.

Fig. 29. Superoxide dismutase activity (U mg proteína-1) in soybean seeds cv. BRS133 and Pintado treated at recommended dose of Cruiser (D1) and check (D0), under PEG. **ns**: not differ significantly for each imbibition period.
