An Evaluation of Arabidopsis thaliana Hybrid Traitsand Their Genetic Control

摘要

Heterosis is an important phenomenon in agriculture. However, heterosis often greatly varies among hybrids and among traits. To investigate heterosis across a large number of traits and numerous genotypes, we evaluated 12 life history traits on parents and hybrids derived from five Arabidopsis thaliana ecotypes (Col, Ler-0, Cvi, Ws, and C24) by using a complete diallel analysis containing 20 hybrids. Parental contributions to heterosis were hybrid and trait specific with a few reciprocal differences. Most notably, C24 generated hybrids with flowering time, biomass, and reproductive traits that often exceeded high-parent values. However, reproductive traits of C24 and Col hybrids and flowering time traits of C24 and Ler hybrids had no heterosis. We investigated whether allelic variation at flowering time genes FRIGIDA (FRI) and FLOWERING LOCUS C (FLC) could explain the genotype- and trait-specific contribution of C24 to hybrid traits. We evaluated both Col and Ler lines introgressed with various FRI and FLC alleles and hybrids between these lines and C24.Hybrids with functional FLC differed from hybrids withnonfunctional FLC for 21 of the 24 hybrid-trait combinations.In most crosses, heterosis was fully or partially explained byFRI and FLC. Our results describe thegenetic diversity for heterosis within a sample of A. thalianaecotypes and show that FRI and FLC are majorfactors that contribute to heterosis in a genotype and trait specificfashion.