Genetic Gains to Grain Yield of Maize Varieties for Small Farmers in Brazil

Abstract

The demand for expanding the genetic base in working collections of older maize breeding programs points to the need to pool efforts and reaffirm methodologies for conserving genetic variability that can still be accessed in maize populations. The objective of the work was to select full sib maize progenies and to estimate genetic gains in the first cycle of reciprocal recurrent selection for common maize intended for cultivation in a region characterized by family farm, in Brazil. We evaluated 120 full sib families of maize from crossbreeding between individuals of the Cimmyt and Piranão varieties. Competition trials were conducted at two experimental stations in the state of Espírito Santo, Brazil. A randomized block design was adopted with 2 repetitions, arranged in sets. Different selection indexes were tested in order to enhance gains in productivity and prolificacy. The selection of 40 superior families made it possible to estimate a gain of 0.77 Mg ha-1 in grain productivity for producers in the region. With these results, we discussed the importance of work to improve maize populations for small producers to motivate the conservation of the genetic variability of tropical maize germplasm. Thus, from the results obtained in this study, we show the possibility of investing in technologies aimed at small producers in order to motive the conservation of genetic resources, food sovereignty of producers and, consequently, world security, given the importance of this culture for human feed.