A complete chromosome substitution mapping panel reveals genome-wide epistasis in Arabidopsis.

Chromosome substitution lines (CSLs) are tentatively supreme resources to investigate non-allelic genetic interactions. However, the difficulty of generating such lines in most species largely yielded imperfect CSL panels, prohibiting a systematic dissection of epistasis. Here, we present the development and use of a unique and complete panel of CSLs in Arabidopsis thaliana, allowing the full factorial analysis of epistatic interactions.

Low-coverage resequencing detects meiotic recombination pattern and features in tomato RILs.

Traditional plant breeding relies on meiotic recombination for mixing of parental alleles to create novel allele combinations. Detailed analysis of recombination patterns in model organisms shows that recombination is tightly regulated within the genome, but frequencies vary extensively along chromosomes. Despite being a model organism for fruit developmental studies, high-resolution recombination patterns are lacking in tomato.

Graft-transmissible movement of inverted-repeat-induced siRNA signals into flowers.

In plants, small interfering RNAs (siRNA) and microRNAs move to distant tissues where they control numerous developmental and physiological processes such as morphogenesis and stress responses. Grafting techniques and transient expression systems have been employed to show that sequence-specific siRNAs with a size of 21-24 nucleotides traffic to distant organs. We used inverted-repeat constructs producing siRNA targeting the meiosis factor DISRUPTED MEIOTIC cDNA 1 (DMC1) and GFP to test whether silencing signals move into meiotically active tissues.

Exploring genetic variation in the tomato (Solanum section Lycopersicon) clade by whole-genome sequencing.

We explored genetic variation by sequencing a selection of 84 tomato accessions and related wild species representative of the Lycopersicon, Arcanum, Eriopersicon and Neolycopersicon groups, which has yielded a huge amount of precious data on sequence diversity in the tomato clade. Three new reference genomes were reconstructed to support our comparative genome analyses. Comparative sequence alignment revealed group-, species- and accession-specific polymorphisms, explaining characteristic fruit traits and growth habits in the various cultivars.

Hybrid recreation by reverse breeding in Arabidopsis thaliana.

Hybrid crop varieties are traditionally produced by selecting and crossing parental lines to evaluate hybrid performance. Reverse breeding allows doing the opposite: selecting uncharacterized heterozygotes and generating parental lines from them. With these, the selected heterozygotes can be recreated as F1 hybrids, greatly increasing the number of hybrids that can be screened in breeding programs.

Reverse breeding in Arabidopsis thaliana generates homozygous parental lines from a heterozygous plant.

Traditionally, hybrid seeds are produced by crossing selected inbred lines. Here we provide a proof of concept for reverse breeding, a new approach that simplifies meiosis such that homozygous parental lines can be generated from a vigorous hybrid individual. We silenced DMC1, which encodes the meiotic recombination protein DISRUPTED MEIOTIC cDNA1, in hybrids of A.

Reverse breeding: a novel breeding approach based on engineered meiosis.

Reverse breeding (RB) is a novel plant breeding technique designed to directly produce parental lines for any heterozygous plant, one of the most sought after goals in plant breeding. RB generates perfectly complementing homozygous parental lines through engineered meiosis. The method is based on reducing genetic recombination in the selected heterozygote by eliminating meiotic crossing over.