ZmCCT and the genetic basis of day-length adaptation underlying the postdomestication spread of maize

摘要

Maize was domesticated from a wild grass, teosinte, that grows only in tropical environments in Mexico (1). Maize agriculture spread from its Meso-American center of origin to Canada and Chile before the arrival of Columbus. The transition to flowering in teosinte is highly sensitive to small changes in day lengths that occur in its native range, perhaps as a way to coordinate flowering with rainfall patterns. In contrast, reproductive fitness for maize of the higher latitudes depends on its capacity to flower under much longer summer day lengths (Fig. PI). Thus, the spread of maize from its tropical center of origin to the higher latitudes of the Americas required selection for adaptation to longer day lengths. Genetic analysis of the differences in photoperiod response among teosinte, tropical maize, and temperate maize revealed moderately complex inheritance involving more than 10 genes, one of which, ZmCCT, is similar to an important regulator of day-length response in rice.