INBREEDING AND COANCESTRY OF THE MAJOR COMMERCIAL FRESH MARKET PEACH CULTIVARS IN CHINA

Thirty cultivars were selected for pedigree analysis based on their importance as breeding stock or in commercial production in China. An inbreeding analysis indicated that the mean inbreeding coefficients were 0.012 for Case I (unknown parentage assumed to be to an unrelated genotype) and 0.153 for Case II (open pollination assumed to be selfed). This is much lower than that of the freestone peach cultivars of the eastern USA and that of peach and nectarine cultivars from University of Florida breeding program. The mean coefficient of coancestry among the 30 cultivars was also much lower than that reported for peaches of the Eastern United States. This indicates that main commercial fresh market Chinese peach cultivars are less inbred and have a greater genetic diversity than the fresh market cultivars used in the eastern USA.