Genetic Gains in Plant Breeding

Yield potential and its stability, host plant resistance to pathogens and pests affecting crops, adaptation to stressful environments, resource-use efficiency and quality traits can be improved after delivering genetic gains in agro-ecosystems, thus ensuring food to end hunger and improving human health through nutrition sustainably (i.e., Sustainable Development Goal 2). Genetic gains depend on available heritable variation in the breeding population, the selected fraction of the population to be parents of the next generation and the timeframe for completing a selection cycle. They can be further advanced by improving accuracy, increasing selection intensity, enhancing genetic variation and shortening breeding cycles.

The breeder’s equation predicts changes in traits due to selection and is defined as Δ_G = [(ck σ²_g’)/(y σ_P)], where c, k and y are the parental control, a function of the selection intensity, and number of years to complete one recurrent selection cycle, respectively, while σ²_g’ and are σ_P the genetic variance among offspring or families, and the square root of the phenotypic variance, respectively. This measurement of selection response is also used in breeding for goal targeting, assessing achievements, defining methods, and decision making. This special issue on Genetic Gains in Plant Breeding aims to bring together articles showing research results on genetic gains either by measuring it through cultivar releases or (recurrent) selection in crops that feed the world. Articles showing new genetic enhancement approaches, selection methods and breeding tools that may increase or speed the rates of genetic gains are also welcome. We also encourage authors to submit manuscripts on expanding the use of germplasm held in genebank for bettering genetic gains in breeding programs.

Guest Editor Faculty Professor Rodomiro Ortiz, PhD (Madison, 1991) Chair of Genetics and Plant Breeding Department of Plant Breeding, Swedish University of Agricultural Sciences, Alnarp, Sweden