Inbreeding depression simulation in popcorn cultivars to estimate the effective population size for germplasm conservation

Abstract

Nowadays the corn variability is preserved mainly in germplasm banks. A population maintained in a germplasm bank can lose genetic variability when regenerations are performed with an inadequate effective population size. We therefore aimed at an estimation of the effective population size that minimizes alterations in the plant means of ear height, prolificity index, weight of 100 grains, grain yield and expansion capacity after ten regenerations in six popcorn populations. Six populations and their respective selfed generations were appraised in complete blocks with two replications. Yield was the trait with the most pronounced inbreeding depression. Population Rosa-Claro presented the strongest depression for yield (94.3%) and was used to simulate different effective sample sizes. It was concluded that an effective sample size of 200 unrelated non-inbred plants is enough to minimize inbreeding depression after ten regenerations, in all analyzed traits in the six populations.