Dormancy breaking and biochemical processes associated with germination of Erythrina falcata Benth. seeds

ABSTRACT

Background:

The aim of this research was to investigate the efficiency of methods to overcome primary dormancy and biochemical processes associated with germination of Erythrina falcata Benth seeds. Seeds were submitted to dormancy overcoming treatments and the water uptake pattern was analysed. We then evaluated the activity of the antioxidant enzymes SOD, CAT, and APX, and quantified lipid peroxidation levels, hydrogen peroxide content and total protein content. The experiments were performed in a completely randomized design and the statistical analysis used was Scott-Knott test at 5% probability.

Results:

Mechanical scarification with sandpaper leads to approximately 94% of germination in E. falcata, while control non-scarified seeds show only approximately 37% of germination. Treatments with hot water led to high mortality in E. falcata seeds. Rapid water absorption was observed in the first 18 hours of imbition when the seeds were scarified with sandpaper, and radicle emergence was observed after 36 hours. During imbibition there was an increase of antioxidant enzyme activity and a decrease in lipid peroxidation and H₂O₂ production, suggesting an efficient mechanism for regulating imbibition damage. A decrease in the total protein content was observed during germination of E. falcata seeds.

Conclusions:

Mechanical scarification is an efficient method for breaking dormancy of E. falcata seeds. During germination of E. falcata seeds there is a reduction in the production of H₂O₂ and lipid peroxidation, and an increase in the activity of antioxidant enzymes. The total protein content decreased along the germination time.

Key words:
Primary dormancy; seed metabolism; antioxidants; enzyme activity.

HIGHLIGHTS

Mechanical scarification is an efficient method to overcome dormancy in E. falcata seeds. Scarified E. falcata seeds show rapid and uniform germination. The activity of antioxidant enzymes increases during the germination of E. falcata seeds. There is a decrease in total protein content during germination of E. falcata seeds.