GENETIC IMPROVEMENT OF "THREE-MONTH-OLD LAGOON" MAIZE ̈( 1)

Abstract

A regional maize variety, Lagunero de Tres Meses, with an out­standingly short life cycle (90 days from planting to harvest), was subjected to a breeding process in its own habitat, la Laguna region, a part of the dryland Tropics of Mexico.

Fourteen s₁ lines, derived from that variety, were combined to form a synthetic composite, since these lines showed a high general combining ability during two years. Then the synthetic composite was subjected to modern mass selection for 6 consecutive cycles. Lineal regresion of grain yíeld agatn at the number of cycles under mass selection showed a significant 3.6% gain per cycle, while earliness and. phenotypic variance for grain yield remained unchanged.