Herencia del vigor de plántula y su relación con caracteres de planta adulta en líneas endogámicas de maíz tropical

Abstract

In plant breeding programs seed and seedling vigor are important to assure germination, emergence and initial development of the plant. This study was conducted to determine inheritance type of traits related to maize seedling and adult plant vigor and to correlate initial seedling vigor with adult plant traits. To this end, we used the effects of general combinatory aptitude (ACG), specific combinatory aptitude (ACE) and reciprocal effects (ER) obtained from the evaluation of six inbred lines of tropical maize and their direct and reciprocal crosses in a dialelic design. The 30 resulting hybrids were evaluated in Tepalcingo, Morelos, and Iguala, Guerrero, in a randomized complete block experimental design with three replications. We evaluated emergence percentage, initial vigor, vigor index (I), seedling height, days from sowing to 50% masculine and feminine flowering, number of leaves below the ear, total leaf number and plant height. The variation attributable to AGC, ACE and ER was significant (p≤0.01) for all of the traits evaluated, although to a lesser degree for ACE and ER. The dominance variance predominated in seedling traits but not in adult plant traits, for which additive variance was greater. The lines CML 254 and CML 411 (seedling) and CML 399 (adult plant) exhibited high ACG. The reciprocal effects showed that the CML 254 and CML 396 lines, as female parents, produced hybrids with good initial seedling vigor and good development of the adult plant. ER regressions of initial vigor were significant for the ER emergence percentage (R2=0.53), vigor index I (R2=0.62) seedling height (R2=0.55), leaves below the ear (R2=0.40) and total leaf number (R2=0.26). There was no association between initial vigor and adult plant traits.