Genotipos de maíz tolerantes a salinidad; un estudio preliminar para iniciar un programa de pelección

Abstract

Maize genotypes for soil salinity tolerance, an approach to a selection program. Summary. The objective of this work was to identify maize genotypes tolerant to salinity by means of field and laboratory evaluation. The field experimentation was made during the spring -summer cycle 2002, in Navidad, N. L., México under irrigation conditions. The experimental design was a completely randomized blocks one, in which the following variables were evaluated: grain yield, plant and corncob height, days to feminine and masculine flowering, in 14 genotypes. In one of the repetitions, foliar samples were taken at the moment of appearance of the flag leaf, with intention of determining its mineral contents. The length of radicle and plantule of only 13 genotypes was evaluated in the laboratory (without genotype 8), in five levels of salinity (0, 3, 6, 9, 12 decisiemens), under a completely randomized design with a factorial arrangement. The analyses of variance for genotypes in field showed differ ences (p<.01), and the DMS (α=0.01) test for yield considered genotypes 1 and 2 as statistically equal, with average yields of 6964.3 and 6619.5 kg ha-1, but superior to the An-447 witness (5996.3 kg ha-1). Foliar analysis showed that levels of N, P and K were low, as opposite to those of Ca, Mg and S, which means that these last ones are present in the soil in great amounts and cause its salinity, which causes a deficient absorption of first ones.