Respiratory changes with stratification of pear seeds

Experiments on the stratification of seeds of pear (Pyrus communis cv. Bartlett) indicate that there is a progressive increase in respiratory capacity, with about a three‐fold increase developing during a 30‐day stratification period. Evidence is presented suggesting this increase in respiratory capacity occurs in the cytochrome oxidase pathway and not in the alternative pathway of respiration. The increase is much less pronounced if the seeds are held at 25°C rather than at 6°C. The seed coat serves as a barrier to the expression of the increased respiratory capacity.