Maiz de Ocho, the frontier maize in the northward spread and adaptation of maize

Ever since ca. A.D. 700, Maiz de Ocho has been the pioneer race at the northernmost fringes of maize cultivation in North America. At this date, some 3000 years after its spread southward into South America, this new race of maize broke through the previous barriers of short growing seasons and long day-lengths as it expanded northward. Maiz de Ocho has a special attribute that made this dramatic event possible. In response to selection directed toward early flowering it can progressively reduce the duration of its vegetative phase, as measured by the number of leaves from ground level to the lower ear shoot. The ultimate in earliness emerged when Maiz de Ocho finally reached the Gaspe Peninsula of Canada. In the earliest flowering selections of Gaspe Flint, the vegetative phase is reduced to zero with the ear shoot borne in the axil of the first leaf. The total leaf number is only five so that the preinduced plant comes up ready-formed like a crocus. Most Gaspe Flint plants have a total of seven leaves with a vegetative phase of only two leaves corresponding to two days of growth during germination.

Always somewhat behind in space and time, the more productive dent corns are still spreading northward into the former territory of the flints. By means of introgression into its more southernly neighbors, Maiz de Ocho has always prepared the genetic way for the dented immigrants to settle the north country. When we use the northernmost types of Maiz de Ocho to adapt southern types to the North in our breeding programs, we extend the successes of history. An understanding of the role of Maiz de Ocho in adapting tropical maize to temperate areas will make it easier for corn breeders to better utilize the entire range of genetic variability in the total maize gene pool.

Walton C. Galinat
 
 


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