Oxygen- and ethylene-induced germination in dormant peach seeds

Low embryo viability and recalcitrant germination of peach seeds limits the production of peach seedlings for nursery stock and of new breeding lines.We show that super-ambient oxygen (100% O 2 ) and, furthermore, co-application of oxygen and ethylene (10 μL L -1 oxygen) led to significant germination in seeds from established peach cultivars, including 'Blake', 'Loring', and 'Lovell', and also from selected breeding parents of 'Guardian ® ' peach.After 42 days in oxygen-ethylene atmosphere germination was close to 100% in 'Blake' and 'Loring' and around 80% in 'Lovell', but was nil in air and around 4 to 20% in air plus ethylene, depending on the cultivar.Germination reached 50% or higher in new breeding lines of 'Guardian ® ' peach seeds, despite hindrance by fungal infestation.Super-ambient oxygen also accelerated germination of cold-stratified seeds, compared to seeds held in air alone.These data suggest that super-ambient oxygen, particularly in combination with ethylene, might be used as working protocol to achieve substantial germination in dormant peach seeds.