Selection of inbred maize (Zea mays L.) progenies by topcrosses conducted in contrasting environments

Abstract

The aim of this study was to identify inbred progenies of S maize (Zea mays L.) plants that were efficient at a low level of technology and responsive at a high level of technology through the use of topcrosses. Two contrasting environments were created using two levels of base fertilization and topdressing, so that the levels of nitrogen, phosphorus, and potassium were applied four times higher in one environment than in the other. We used S progenies derived from commercial hybrids in topcrosses with two testers (an elite line from the flint heterotic group and an elite line from the dent heterotic group). The progenies and three controls were evaluated in an augmented block design in Nossa Senhora das Dores, SE, Brazil in the 2010 crop season. The average grain yield in the high-technological level was 21.44% greater than that in the low-technological level. There were no changes in progeny behavior in the two technological levels for grain yield. The testers did not differ in the average grain yield of the progenies at the two technological levels. Therefore, it is possible to select progenies derived from commercial hybrids that have an efficient response to fertilization.

Combining ability and potential of s1 popcorn progenies for early selection

“…The combinational ability of a line is defined by its ability to transfer the characteristics of interest to the hybrid seed. The genotypes used in the crosses must exhibit an expressive combinatorial ability to produce favorable combinations (Rodrigues, Pacheco, Guedes, Pinho, & Castro, 2016).…”

Selection of maize lines and prediction of hybrid and synthetic means using intergroup topcrosses

“…This greatly increases with an increase in the number of parents, making breeding programs more expensive (Inocente et al 2021). To reduce the number of crosses for evaluation, breeders have opted to use topcrosses (Rodrigues et al 2016, Rosa et al 2020. This method evaluates the lines in crosses with common testers, allowing the assessment of the genetic values of individuals from the population to be improved (Miranda Filho 2018).…”