Domestication reshaped the genetic basis of inbreeding depression in a maize landrace compared to its wild relative, teosinte.

Inbreeding depression is the reduction in fitness and vigor resulting from mating of close relatives observed in many plant and animal species. The extent to which the genetic load of mutations contributing to inbreeding depression is due to large-effect mutations versus variants with very small individual effects is unknown and may be affected by population history. We compared the effects of outcrossing and self-fertilization on 18 traits in a landrace population of maize, which underwent a population bottleneck during domestication, and a neighboring population of its wild relative teosinte.

A conserved genetic architecture among populations of the maize progenitor, teosinte, was radically altered by domestication.

Very little is known about how domestication was constrained by the quantitative genetic architecture of crop progenitors and how quantitative genetic architecture was altered by domestication. Yang et al. [C.

TeoNAM: A Nested Association Mapping Population for Domestication and Agronomic Trait Analysis in Maize.

Recombinant inbred lines (RILs) are an important resource for mapping genes controlling complex traits in many species. While RIL populations have been developed for maize, a maize RIL population with multiple teosinte inbred lines as parents has been lacking. Here, we report a teosinte nested association mapping (TeoNAM) population, derived from crossing five teosinte inbreds to the maize inbred line W22.

The genome-wide dynamics of purging during selfing in maize.

Self-fertilization (also known as selfing) is an important reproductive strategy in plants and a widely applied tool for plant genetics and plant breeding. Selfing can lead to inbreeding depression by uncovering recessive deleterious variants, unless these variants are purged by selection. Here we investigated the dynamics of purging in a set of eleven maize lines that were selfed for six generations.