JoAnne Skelly: Apples versus crabapples

My friend Will asked me about the relationship between apples and crabapples. He wondered if apples were hybrids of crabapples. I had thought they were different, but after extensive research, I found that their hybridization goes back thousands of years and crossed many countries and even continents.

According to Sunset Western Garden Book, apples are “probably natural hybrids of Malus sylvestris (the European crabapple) and Malus pumila, also known as Malus domestica (the common apple). In a PLOS Genetics article, 2012, A. Cornille and coauthors write that their research proves the apple’s primary gene pool comes not only from Malus domestica, but also from the crabapple species Malus sieversii (the Central Asian wild apple) with Malus sylvestris being a major secondary contributor after the apple was introduced in Europe.

No matter what exact crabapple species the domestic apple is derived from, we know it hybridized over a long period of time with contributions from various wild species. Apples distantly related to the domestic apple appeared in the Near East over 4,000 years ago corresponding to the first recorded use of grafting (Cornille, et al.). The Greeks and Romans later introduced these apples to Europe and North Africa where they crossed with the European crabapple. The resulting domestic apples then made their way to the United States with the European colonists.

These common cultivated apples are now found in gardens and yards throughout much of the United States and the temperate world. They also naturalized in the wild. Johnny Appleseed (John Chapman) supposedly played a legendary role in this. There are now 7,500 known cultivars and varieties, which sounds very impressive. However, the numbers are down from over 10,000 varieties historically. Ten of the most popular cultivars make up over 90 percent of production in the United States (Oregon State Extension)

Although anyone who has ever bit into a crabapple knows how tart they are, some crabapples are grown for edible fruit from which jams, jellies and even pickles are made. Occasionally, crabapples are added to apple cider to give it a tang. Crabapple fruit vary in size, depending on the variety. However, most crabapples are grown for their spectacular spring floral displays with flower colors ranging from white and pink to red or magenta.

I found the genetics research on apples and crabapples fascinating. It tells the story of the apple’s extensive travels around the world to become a favorite fruit. It’s fun to be a plant nerd.

JoAnne Skelly is Associate Professor & Extension Educator, Emerita at University of Nevada Cooperative Extension. She can be reached at skellyj@unce.unr.edu.