EFFECT OF TWO TESTERS ON THE SELECTION OF TROPICAL MAIZE LINES

Abstract

Twenty-three S₃ lines from a cross between two improved populations (Tutifruti x Compuesto Cardel) were evaluated for identifying the sets lines from the agronomic point of view as well as better hybrids than controls. Both improved populations were crossed to two testers. One being narrow genetic based (testcross) and the other being wide genetic based (topcross). The experiment was established in two environments and two replications in the State of Veracruz in 1990. The traits recorded included plant height, date to flowering, prolificy and yield, these variables were analyzed under a randomized block design with factorial arrangement taking as factor A the lines and factor B the testers. The results were superior significantly for lines (A) which allowed to make a good selection; the most outstanding lines throughout the testers were the line 37 and 7 with 9.473 and 9.203, respectively. The best hybrids were in combination with the line 17 and 7 that present yields of 9.685 and 9.509, respectively. Otherwise, the tester (single cross) overyielded significantly VAN 555 variety with 0.540 t/ha; however, the most efficient tester in the discriminating for yield was the VAN 555 variety.