Johnny Appleseed - The problem with growing apple trees from seed

In a quest to produce homegrown apples like those found at the local grocery store, many people plant apple seeds in the garden only to discover that, after a tremendous amount of time and effort, the apples they have produced are completely different from the original. The problem with planting apple seed is that the new tree may bear little or no resemblance to the parent apple from which the seed came. Apple seeds do not reproduce true to type. Apples are cross-pollinators, meaning they require pollen from another apple (of a different variety) in order to produce fruit. In a cross-pollinated system, insect vectors (pollinators) such as honeybees or bumblebees control the transfer of pollen from one plant to another. Pollen sources (pollinizers) can include many different types of apple, or even crabapple. Therefore, the seeds produced inside the fruit will receive half of their genes from an outside pollen source. The seed from a grocery store McIntosh apple would only have half of the McIntosh genes and half of the genes from the male pollinizer. Therefore, a seed planted from this apple may grow into a tree with an entirely different appearance, colour or flavour. A single apple will typically contain several genetically different seeds. Planting 10 seeds from a single apple will likely yield 10 trees that differ in some way from each other and from the parent. There are a few varieties of apple that can successfully self-pollinate in which case growing out the seed may be successful. However, encouraging cross-pollination often leads to higher productivity and fruit yield. Other cross-pollinating fruits include plum and pear; seeds from these will also not reproduce true to type.

Some commercial apple varieties are generated by crossing two genetically different parents in order to produce offspring containing the most desirable traits from each parent. For example, the ever-popular Fuji apple is the product of a cross between Ralls Janet and Red Delicious. It is superior in both sweetness and juiciness. The Fuji is then vegetatively propagated in order to maintain those desirable characteristics generated from the original cross. In northern climates, cuttings from superior offspring are grafted onto hardy (often native) rootstocks to increase their adaptability and survival. Vegetative propagation (cuttings, grafting, layering, tissue culture etc.) is the only way to obtain a genetically identical apple.

Relevant web sites:
www.hort.purdue.edu/ext/pollination.html

Other references:
Westwood, M.N. 1978. Temperate Zone Pomology. W.H. Freeman and Company, San Francisco. 427 pages.