Development of DNA based technology for fingerprinting and genetic studies in cranberry

Identification and discrimination of most cranberry varieties is problematic. There are few qualitative morphological traits with which to discriminate varieties of cranberry. Apple varieties, on the other hand, are easily discriminated, i.e. the fruit of Golden Delicious versus Red Delicious apples. Vegetative morphology, e.g. leaf shape, size, etc., of most cranberry varieties is very similar and subject to significant environmental influence. In cranberry, mostly fruit characteristics are used to identify varieties including fruit size, shape, seed number, calyx and stem end morphology, and patterns of ripening. For example, the pyriform shape of ‘Ben Lear’ fruit is a principle character criterion for evaluation of beds designated as Ben Lear. Vegetative characteristics are sometimes used to evaluate or identify varietal mixtures/off-types in beds. For example, patches of different growth architecture or color can be observed in beds in early spring and during fall color development. However, even fruit characteristics of cranberry are largely continuums of size, shape and color. Fruit shape can be influenced by seed number, which can be impacted or dependant on pollination weather, or pollinator abundance or quality. Thus, there has long been an urgent need for the development of qualitative traits or markers to help in the discrimination of cranberry varieties.