SELECTIONS FOR DROUGHT RESISTANCE IN A CORN COMPOUND IN ZACATECAS

Abstract

A research work was carried out in 1987 in Zacatecas, México, to evaluate seven cycles of modified ear-to-row selection obtained from the Calera-74 com composite (Zea mays L.). Selection was practiced under full irrigation, drought stress and based upon the relation irrigation/drought. The objetive was to determine the genetic gain obtained by selection. The 21 populations, the original
collection and 3 checks were evaluated under three soil moisture conditions: 1) lrrigation; 2) Drought during the flowering period; and 3) Drought. Increases in yield ranked from 0.4 to 3% by cycle of selection. The genotypes obtained by the irrigation/drought criterion showed the greatest increases under moderate and drastic conditions of drought while genotypes selected under drought and irrigation conditions showed the greatest genetic gains only under the drastic conditions of the trial.