By Sweta
Exclusive to Tractorexport
Genetic diversity refers to different types of species as well as diversity present within a species. It is important as in absence of genetic diversity a species may show inbreeding depression and end up in harmful or lethal mutations. Genetic diversity helps a species to adapt in changing environments.
Corn has been cultivated for thousands of years in the US. In the corns of US we can find genetic diversity in color, shape of seed and between the different varieties in terms of yield, disease resistance, etc. Corn Yaak’a is the staple crop of Acoma Pueblo community in North America. It is an example of great diversity within the corn seeds. We can find red, blue, white or seeds of mixed colors on a single ear. Likewise, Oaxacan Green is a corn variety used to make tamales (green flour) by the Zapotecs in Mexico.
There are three categories of corn grown in US:
• Landraces
Landraces are the primitive cultivars which were cultivated by farmers for many generations. Landraces are more resistant to different abiotic and biotic stresses and posses greater genetic diversity than heirloom or hybrid corns. Palomero Toluqueno, a popcorn landrace variety is from Mexico. Chapalote is another variety which is a primitive cultivar. Gourdseed is a landrace variety which is commercially sold as an heirloom corn variety.
• Heirlooms
Heirlooms are commercial varieties of the past but are now gradually being replaced by the hybrid varieties of maize. Heirlooms are open pollinated varieties whose seeds can give same characteristics and performance from generation to generation. Country gentleman is an heirloom variety. Stowell’s Evergreen is another heirloom variety of white sweet corn. Yellow sweet corn variety is Golden Bantam.
• Hybrid maize
Hybrid maize seed is produced by crossing two elite inbred with consistent phenotypes. The resultant hybrid will show better performance and characteristics than its parent plants. Hybrid varieties of super sweet corns are Honey & Pearl, Candy Corner, Dazzle, Butter fruit and Snow White. These varieties contain a gene shrunken-2 (sh2). Lancaster Sure crop Corn and Sunshine Sweet Corn are other hybrid varieties with superior performance. But one of the drawbacks of growing hybrids is that you cannot save its seed to use every year as it will not have the same characteristics of the original hybrid seed you had planted. So, you need to purchase its seeds every year for cultivation.
There are several open pollinated varieties like Truckers Favorite, Reid’s Yellow Dent, Silver mine, Boone County White and Silver King which can be replanted from the saved seeds.