Aspects of Female Heredity in the Breeding Progeny of Different Olive Cultivars

摘要

Although the olive is one of the oldest cultivated tree-crop their large number of cultivars is mostly the result of selection from the endemic vegetation and thus, very close to the wild type. Specific cross breeding to improve or modify olive cultivars for specific new growing conditions started about 60 years ago. As most olive cultivars are only partly self compatible and even less so at elevated temperatures during flowering a methodology for cross breeding without flower castration was developed on that basis. In the present study we were able to demonstrate the impact of the female parent on its breeding progeny disregarding the effect of the male parent. Female heredity was clearly dominant over the male one for a considerable number of different parameters in the progeny of most female parentage tested. The most predominant characters of the female parent expressed in its progeny were tree form, size, leaf shape, fruit form, size, oil content and various others. Some mother cultivars induced the expression of specific characters in their progeny considerably more than others. Specifically pronounced characters of the female parent cultivar were in most cases even further amplified in its progeny. This was true for most specific extreme characters except for some clearly receive ones such as lack of anthocyanine biosynthesis in the fruit and in various cases resistance to diseases. For some characters and cultivars 80-90% of the progeny showed a very high similarity with that in the mother plant. For example the oil content in the progeny of 'Kalamata', fruit size in the progeny of 'Kadesh' and tree size in the progeny of 'Manzanillo'. It was of particular interest that fruit characters in most of the progeny plants from any female parent tested were above the level of that expressed in the mother plants.