Overcoming physiological dormancy in common buckwheat (Fagopyrum esculentum Moench)

Abstract 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, the presence of dormancy can impede this process. The dormancy release protocols for buckwheat seeds, which exhibit physiological dormancy, are not available. This study aims to identify effective dormancy-breaking protocols through the use of chemicals and phytohormones namely GA3, KNO3, and H2O2. Buckwheat seeds exhibited high dormancy with only 21% of seeds germinating. Seed treatment with 0.4% KNO3 enhanced germination to 69%. Both KNO3 and H2O2 treatments significantly reduced the time to 50% germination (t50) (2.37 – 2.55 days) and mean germination time (MGT) (3.02 – 3.23 days). These treatments also enhanced the dormancy index (DI) (253.56 - 217.86). The seedling length was enhanced by 55% with 200 ppm GA3. There was an enhancement in seed vigour indices by 305% and 260% in 20 mM H2O2 and 0.4% KNO3 treatments respectively. Compared to the control, all the seed treatments enhanced the α-amylase activity. Both 0.4 % KNO3 and 20 mM H2O2 treatments recorded the highest α-amylase activity. The result suggests that KNO3 and H2O2 treatments reduced seed dormancy and improved seed germination and vigour by increasing the mobilization of seed reserves. Application of 0.4% KNO3 or 20 mM H2O2 as a dormancy release mechanism can be incorporated during seed testing and germplasm evaluation of buckwheat seeds with physiological seed dormancy.