ARS | Publication request: Genomic Resources for the Asparagales

Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: November 1, 2004
Publication Date: November 1, 2004
Citation: Havey, M.J., Jenderek, M.M., Sink, K., Town, C. 2004. Genomic resources for the asparagales. American Society of Agronomy Meetings.

Technical Abstract: Enormous genomic resources have been developed for model plants such as Arabidopsis thaliana and rice, including huge numbers of expressed sequence tags (ESTs), knock-outs of major coding regions, alignment of physical contigs, and sequencing of complete genomes. These resources allow for efficient identification and cloning of genes. However, it is not clear how broadly these genomic resources can be applied to the genetic improvement of more distantly related, economically important plants. In many cases, the most important traits in crop plants are influenced by biochemical processes not clearly present in model systems. Asparagus, garlic, and onion are the most economically important non-graminous crops produced in the US and are members of the monocot order Asparagales, a monophyletic group sister to the order Poales (rice, maize, wheat, and other grasses). Genomic approaches to the genetic improvement of the Asparagales vegetables are difficult due to extremely large nuclear genomes, longer generation times, severe inbreeding depression, and relatively few populations of defined genetic structure. The phylogenetic relationship between the orders Asparagales and Poales may allow the genomic resources developed for the Poales to be applied to the Asparagales. Sequencing of at least 15,000 random cDNAs from a normalized onion library revealed highly homologous single copy ESTs in rice. These cDNAs will be used to map a common set of markers in asparagus, garlic, and onion to estimate the synteny among these vegetables and rice. If synteny existed among these Asparagales vegetables and rice, the enormous genomic resources of rice could be tapped for identification and cloning of economically important genes in the Asparagales. If little to no synteny existed, a model system within the Asparagales should be developed as an aid in the cloning of important genes and the development of new, competitive Asparagales vegetable cultivars.