We can now determine the extent of contamination in any given bog to help determine if variation in cultural characteristics has a genetic or environmental basis. There are two basic methods to improve crops. The traditional method is through selective breeding. The most successful and widely cultivated cranberries and other crops are the direct result of years of careful breeding. Breeding however has its drawbacks.
Breeding is very time consuming and can take many years before a new cultivar can be developed.
Part of the reason breeding can take so long is because undesirable genes are often transferred to progeny along with the desirable genes. The undesirable genes have to then be removed through subsequent crosses. Another limitation of breeding is that the genes available for crop improvement are limited to plants that can be sexually crossed with the crop of interest. Genes for specific characteristics, such as disease resistance, can now be directly inserted into elite cultivars. This technology requires many steps that vary from crop to crop.