Early history of crop presence/introduction into India: VII. American cereal, maize (Zea mays L.)

Abstract

The crop diversity in India have been enriched with the introduction of exotic crops from times immemorial, including maize. Maize originated and is domesticated in south-central Mexico. The semi-domesticated maize from here traveled to Americas and other parts of the world. In different geographical regions the semi-domesticate maize parallelly evolved interacting and adapting with the local environment into new domesticated landraces, besides the completion of domestication at center of origin. This led to the development of several centers of diversity. Genomic evidence suggests that the South American landraces through reverse gene flow (breeding) have further evolved the maize grain types in Central America. Presence of primitive types of maize in Central, East, South-east and South Asia, including India in pre-Colombian ancient times has been evidenced by the archeological proof in form of botanical remains, carving of maize-cob on temple walls, ancient dating, reference in ancient literature and similar looking vernacular names. These evidences confirm the pre-Colombian presence, thereby introduction of maize into old world (Asia) much before the commonly cited introduction for cultivation of maize in 16th century into Asia and in 17th century into India by Portuguese, generating further diversity. During ancient times maize appears to have traveled: 1. via the Mediterranean and Central Asia to Southwest China and further; 2. via Timur, Indonesia in extreme South-east Asia to India, and 3. via South-east Asia following silk route to India. The present article discusses these facets in detail.