The fluxes of H2O2 and O2 can be used to evaluate seed germination and vigor of Caragana korshinskii

Seed deterioration is detrimental to plant germplasm conservation, and predicting seed germination and vigor with reliability and sensitivity means is urgently needed for practical problems. We investigated the link between hydrogen peroxide (H₂O₂) flux, oxygen influx and seed vigor of Caragana korshinskii by the non-invasive micro-test technique (NMT). Some related physiological and biochemical changes in seeds were also determined to further explain the changes in the molecular fluxes. The results showed that there was a good linear relationship between germination and H₂O₂ flux, and that O₂ influx was more suitable for assessing seed vigor. H₂O₂ flux changed relatively little initially, mainly affected by antioxidants (APX, CAT and GSH) and H₂O₂ content; afterward, the efflux increased more and more rapidly due to high membrane permeability. With the damage of mitochondrial respiration and membrane integrity, O₂ influx was gradually reduced. We propose that monitoring H₂O₂ and O₂ fluxes by NMT may be a reliable and sensitive method to evaluate seed germination and vigor.