Reciprocal recurrent selection in Mexican Higland Valleys maize populations under high and low soil nitrogen content [Spanish]

摘要

The objective of this study was to evaluate two cycles of reciprocal recurrent selection in Highland Valley maize (Zea mays L.) populations 902 (A) and 903 (B), from the International Maize and Wheat Improvement Center of (CIMMYT) in soils with high and low nitrogen content. Using selection cycles 0, 1 and 2 of populations A and B, nine crosses A(i)xB(j) (i, j=cycle 1, 2, 3) were formed. The F-2 generation of cycle i of the A population and cycle j of the B population, the A(i)xB(j) crosses, plus ACROSS96902, ACROSS96903, CMS929001, ASPROS721 and CMS939083 as controls, were evaluated in soils with high and low nitrogen at El Batan, Mexico, and in high nitrogen soils at Montecillo, Mexico, in 2000 and 2001. The experimental design was a randomized complete block with three replications. The average yield of the crosses A(i)xB(j) (8.24 t ha(-1)) was not statistically different from the controls (8.45 t ha(-1)), and populations B-j had the lowest yield (5.55 t ha(-1)). No significant differences were found between genotypes of the two populations. Improvement in grain yield per cycle of selection was not significant and nor was heterosis for average parent.