The Heritage Grain Alliance divides wheat into three major categories corresponding to the three major chromosome changes it endured in its 14,000 year evolution as a food source, diploid, tetraploid and hexaploid.
The diploid wheats (2n=14 chromosomes) are the original and oldest wheats. They are known generally as the “Einkorns” and are basically improved or selected wild grasses.
After a cross with a wild goat grass sometime later in history, wheat varieties emerged as tetraploid (4n=28 chromosomes). Tetraploids were seemingly adaptable to more locations and evidence of their use is found more widely than Einkorn. Emmer, Durum, Polish, Khorasan, Turdigum and Zanduri wheats are all considered tetraploid.
Somewhere along the line, maybe as early as 8,000 years ago, tetraploids crossed with Aegilops and hexaploid wheat was born (6n=42 chromosomes). Even though the hexaploids have been around for thousands of years, they are often called “the modern wheats” because most modern varieties in use today are indeed hexaploid. Before industrial agriculture became widespread tens of thousands of distinct hexaploid varieties were being grown around the world. Our original Heritage Grain Trials Program, begun at Rocky Mountain Seed Alliance and now with the Heritage Grain Alliance, continues to find, grow, and increase the seed for the most successful varieties in use in our region before chemicals and modern irrigation.