Accelerated Generation of Selfed Pure Line Plants for Gene Identification and Crop Breeding

Abstract

Production of pure lines is an important step in biological studies and breeding of many crop plants. The major types of pure lines for biological studies and breeding include doubled haploid (DH) lines, recombinant inbred lines (RILs), and near isogenic lines (NILs). DH lines can be produced through microspore and megaspore culture followed by chromosome doubling while RILs and NILs can be produced through introgressions or repeated selfing of hybrids. DH approach was developed as a quicker method than conventional method to produce pure lines. However, its drawbacks of genotype-dependency and only a single chance of recombination limited its wider application. A recently developed fast generation cycling system (FGCS) achieved similar times to those of DH for the production of selfed pure lines but is more versatile as it is much less genotype-dependent than DH technology and does not restrict recombination to a single event. The advantages and disadvantages of the technologies and their produced pure line populations for different purposes of biological research and breeding are discussed. The development of a concept of complete in vitro meiosis and mitosis system is also proposed. This could integrate with the recently developed technologies of single cell genomic sequencing and genome wide selection, leading to a complete laboratory based pre-breeding scheme.

Candidate Genes for Freezing and Drought Tolerance Selected on the Basis of Proteome Analysis in Doubled Haploid Lines of Barley

“…DHs are derived from in vitro cultured haploid cells of male/female gametophytes redirected towards embryogenic development, followed by spontaneous or chemically-induced genome diploidization. The most important advantage of DH technology in comparison with conventional breeding methods is the possibility to achieve complete homozygosity in one generation, allowing a reduction in the time necessary for release and dissemination of new cultivars [13]. Moreover, due to the lack of dominance effects and new pleiotropic or epistatic interactions [14], the whole inherent genetic diversity and potential could be revealed in offspring populations.…”

Identifying molecular markers suitable for Frl selection in tomato breeding

“…Generating PCR-based markers from some of these SNPs enabled us to develop new markers. As the generation of pure lines involves many crossings and selfings, the chances of a recombination event increase with each additional crossing and, thus, tight linkage of marker becomes more important (Yan et al 2017). Testing our markers on commercial varieties that had been independently developed showed that these new markers also co-segregated with Frl phenotype, indicating that the marker generated in this study is very tightly linked to Frl and applicable to multiple varieties.…”

Hydroponic Systems for Arabidopsis Extended to Crop Plants

“…Similar multi-lab reproducibility experiments with hydroponically grown Arabidopsis plants are not available, but provide an exciting opportunity for new study. Exploiting closed or semi-closed hydroponics tested with Arabidopsis could be an important step in speed breeding and the analysis of RILs or NILs of fast-cycling crop species [26], as described below.…”