Overcoming physiological dormancy in common buckwheat (Fagopyrum esculentum Moench)

The viability status of every accession stored in a seed bank is essential for effective germplasm conservation, and it is often assessed through germination tests. However, dormancy can hamper this process. Currently, no dormancy-breaking protocols exist for buckwheat (Fagopyrum esculentum Moench) seeds, which exhibit physiological dormancy. In the present study, using phytohormones and chemicals, namely, gibberellic acid ( GA(3)), KNO3, and H2O2, we identified effective seed dormancybreaking protocols. Buckwheat seeds exhibited a high degree of dormancy, with only 21% of seeds having germinated. Treatment with KNO3 (0.1%, 0.2%, or 0.4%) and H2O2 (5, 10, or 20 mM) significantly improved seed germination and the dormancy index, and decreased the time to 50% germination and mean germination time. Furthermore, treatment with 200ppm GA(3) improved seedling length by 55%. Moreover, treatments with 20-mM-H2O2 and 0.4%-KNO3 improved seed vigor indices by 305% and 260%, respectively. Compared with the control, a-amylase activity was higher for all seed treatment groups. The groups treated with both 0.4%-KNO3 and 20-mMH(2)O(2) had the highest alpha-amylase activity. Thus, treatment with KNO3 (0.1%, 0.2%, or 0.4%) or H2O2 (5, 10, or 20 mM) can be incorporated as a dormancybreaking protocol for seed testing and germplasm evaluation of buckwheat seeds with physiological seed dormancy.