The home field advantage of modern plant breeding

Abstract

Since the mid-20 th century, crop breeding has driven unprecedented yield gains. Breeders generally select for broadly-and reliably-performing varieties that display little genotype-byenvironment interaction (GxE). In contrast, ecological theory predicts that across environments that vary spatially or temporally, the most productive population will be a mixture of narrowly adapted specialists. We quantified patterns of broad and narrow adaptation in modern, commercial maize (Zea mays L.) hybrids planted across 216 site-years, from 1999-2018, for the University of Illinois yield trials. We found that location was the dominant source of yield variation (44.5%), and yearly weather was the smallest (1.7%), which suggested a benefit for reliable performance in narrow biophysical environments. Varieties displayed a large "home field advantage" when growing in the location of best performance relative to other varieties. Home field advantage accounted for 19% of GxE and provided a yield increase of 1.01 ± 0.04 Mg � ha-1 (7.6% relative to mean yield), yet was both smaller than predicted by a null model and unchanged across time. This counterfactual suggests that commercial breeding programs have missed an opportunity to further increase yields by leveraging local adaptation. Public breeding programs may pursue this opportunity by releasing specialist varieties that perform reliably in narrow environments. As seed sources are increasingly privatized and consolidated, this alternate strategy may compliment private breeding to support global food security.

Local to continental‐scale variation in fitness and heritability in common bean

“…However, progenitors of these entries were grown in North America in pre-Columbian times, and these specific entries were developed for regional production by breeders at many locations that took part in the CDBN trials; thus, local adaptation of CDBN entries to specific North American regions may have arisen from long-term selection of improved material within those regions. If present, local adaptation might be leveraged in breeding programs that have focused on broad-scale adaptation to achieve fitness gains (Ewing et al, 2019). For individual-based selection, breeding programs often measure the heritability of traits of interest, the proportion of phenotypic variation that is genetically determined.…”

Optimizing the P balance: How do modern maize hybrids react to different starter fertilizers?

“…For breeding purposes, more genotypes should be screened in more locations, including poorer P availability classes, and more importantly, the trials should be carried out in more years. It is known from other studies that the effect of starter fertilizers is extremely dependent on the environment [24,50] and on the year [9]. As pointed out, the early phase of the field season in 2019 was extraordinary wet and cold (S1 Fig) . The application of starter fertilizer may buffer against such adverse events and thus provide a kind of insurance for the farmer.…”

A Roadmap for Participatory Chestnut Breeding for Nut Production in the Eastern United States

“…Beyond gains from major adaptations, regional yield and yield stability benefits can be expected from planting locally adapted plant materials, referred to as 'the home field advantage' (Ewing et al, 2019). Promising genotypes developed in conventional breeding programs are often defeated by unpredicted susceptibility to a particular stress within 10 years of release (Vincourt and Pierre, 2018).…”