Improvement of seed germination in apple breeding

A new method of after-ripening of apple seeds, adapted to the production of seedlings in an unheated plastic tunnel has been developed. It enables the successful germination of a very high percentage of seedlings in a short time after stratification treatment. The method consists of individual stratification of fresh seeds in multipots containing moist sphagnum peat, supplemented with mineral nutrients, for about 40-50 days at 2-3 degrees C, and then transferring them to an unheated plastic tunnel, at the beginning of April, i.e. after winter frost. Seeds are extracted from fruits stored at 2-3 degrees C. The seeds tested originated from 11 controlled cross combinations, made in 2001 and 2002, and differed in the length of seed dormancy.