|Krens, Frans - WAGENINGEN UNIVERSITY AND RESEARCH CENTER|
Submitted to: Acta Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/7/2012
Publication Date: 2/13/2013
Citation: Krens, F., Kamo, K.K. 2013. Genomic tools and and prospects for new breeding techniques in flower bulb crops. Acta Horticulturae. 974:139-147.
Interpretive Summary: Further advances are being made using biotechnology for genetic modification of plants. The application of recently developed biotechnological techniques relies upon the knowledge of the nucleotide sequence of a gene. Although the number of plant species with fully sequenced genomes has been increasing, no ornamental bulb crop has been sequenced because of their very large genome sizes. This manuscript summarizes the types and numbers of promoters and genes that have been isolated from ornamental bulb species. It has been found that the promoters isolated from cereal monocots express poorly in the ornamental bulb crops that are also monocots but that differ in control of their expression of genes. The types of genes that have been used for genetic modification of the appearance and disease resistance of flower bulb crops are described. This information will ultimately contribute to further improvement of ornamental bulb crops.
Technical Abstract: For many of the new breeding techniques, sequence information is of the utmost importance. In addition to current breeding techniques, such as marker-assisted selection (MAS) and genetic modification (GM), new breeding techniques such as zinc finger nucleases, oligonucleotide-mediated mutagenesis, RNAi and cisgenesis are totally dependent on knowing gene or allele sequences. Many plant species have been fully sequenced, but none of them represents a bulbous ornamental crop. For a limited number of flower bulb species some EST-libraries have been generated and a similarly low number of bulb promoters and genes have been isolated, characterized, or used for transformation. Most of the functional analyses and applications in genetically modified crops were ectopic, i.e., not in bulbous crops themselves. Genes and promoters originating from other organisms have been used in GM of bulbs aiming for the introduction of disease resistance or the modification of flower traits. In order to enhance consumer acceptance of transgenic GM bulbs and to facilitate obtaining EU approval for cultivation and market introduction, the marker-free technology is being tested.