Abstract
Five meiotic abnormality types have been discovered in the apple clone ‘R1-23’ (2n=2x=34) known for its faculty to produce an important proportion of triploid seedlings after selfpollination. All these types of meiotic abnormalities can lead to the formation of dyads orof triads, and generate in this way non-reduced male gametes (2n). The types 1, 2 and 3 aretheoretically equivalent to the “SDR” (Second Division Restitution) mechanism and the types 4 and 5 correspond to “FDR” (First Division Restitution) mechanism. These non-reduced gamete production phenomena could be exploited in genetic breeding programmes after confirmation of the detected mechanisms and precision of inheritance of the meiotic abnormalities.
