DOI: 10.5061/dryad.5x69p8d3p
title: Fitness consequences of hybridization in a predominantly selfing species: insights into the role of dominance and epistatic incompatibilities

description: Studying the consequences of hybridization on plant performance is
 insightful to understand the adaptive potential of populations, notably at
 local scales. Due to reduced effective recombination, predominantly
 selfing species are organized in highly homozygous multi-locus-genotypes
 (or lines) that accumulate genetic differentiation both among- and
 within-populations. This high level of homozygosity facilitates the
 dissection of the genetic basis of hybrid performance in highly selfing
 species, which gives insights into the mechanisms of reproductive
 isolation between lines. Here, we explored the fitness consequences of
 hybridization events between natural inbred lines of the predominantly
 selfing species Medicago truncatula, at both within- and among-populations
 scales. We found that hybridization has opposite effects pending on
 studied fitness proxies, with dry mass showing heterosis, and seed
 production showing outbreeding depression. Although we found significant
 patterns of heterosis and outbreeding depression, they did not differ
 significantly for within- compared to among-population crosses.
 Family-based analyses allowed us to determine that hybrid differentiation
 was mostly due to dominance and epistasis. Dominance and/or dominant
 epistatic interactions increased dry mass, while decreasing seed
 production, and recessive epistatic interactions mostly had a positive
 effect on both fitness proxies. Our results illustrate how genetic
 incompatibilities can accumulate at a very local scale among
 multi-locus-genotypes, and how non-additive genetic effects contributes to
 heterosis and outbreeding depression.
description: This file contains information about the dataset used for the
 article: "Fitness consequences of hybridization in
 a predominantly selfing species: insights into the role of dominance and
 epistatic incompatibilities" Published in
 Heredity, by Josselin Clo, Joëlle Ronfort and Laurène Gay. For any
 questions, please contact: josselin.clo@gmail.com The
 dataset is composed of two files: -The main dataset
 ("data.csv")<br> -The flowering data
 ("flower_data.csv") ## For flowering
 ## It contains only two columns, giving the flowering
 date of the 2000 individuals (same order as in the main
 dataset).<br> The first column is the number of days since
 01.01.1970, and the second column is the number of days since 01.01.2018
 (these values were used in the<br> manuscript).
 ## For the dataset ## It contains 9
 columns: "female_ID" = The ID of the female
 plants. For consistency with the manuscript 163 = SPA, 18 = FR, 89 = CO3,
 43 = CO2, 02 = CO1. Then XXX-1 and XXX-2<br> refers to the MLG
 number 1 or 2, for example. "male_ID" = same
 as female, but for the pollen donor
 "generation" = The generation of the cross of the
 individual (P= Parental line, F1, or F2)
 "dry_mass" = The dry mass of the plant (in g)
 "graine_tot_complet" = The number of seeds produced by
 a plant "length_shoot_flowering" = the length
 of the main shoot at flowering (in cm, not used in the analyses)
 "seed_weight" = the weight of the seeds (in g, not used
 in the analyses, and not very precise) "bloc"
 = A number between 1 and 8 referring to the 8 blocs of the
 greenhouse "zone" = A number between 1 and 2
 referring to the 2 zones of the greenhouse