1a.Objectives (from AD-416):
The objectives of the project are to. 1)Assemble a collection of natural accessions and 2,000 homozygous T-DNA lines,. 2)Conduct a detailed phenotypic characterization of the collection using a phenomic approach, and. 3)Begin detailed characterization of a select group of mutants and natural accessions.
1b.Approach (from AD-416):
We will apply a phenomic strategy to identify Brachypodium mutants and natural accessions with variation in traits (e.g. biomass, growth rate, root architecture, cell wall composition, water and nutrient use efficiency) relevant to the development of biomass crops. A key advantage of this approach over traditional single trait screens is that we will identify variation in many traits simultaneously and, due to repeated measurements over time and carefully controlled conditions, we will be able to detect relatively modest phenotypic changes. These types of incremental changes may be particularly useful in the development of biomass crops because there may be fewer unintended consequences that decrease other agronomic qualities than with single gene variation that results in large phenotypic changes. To begin the process of translating the variation observed in Brachypodium into biomass crops, we will initiate studies aimed at identifying the genes responsible for the traits in question.
Our ongoing collaborative project to extensively phenotype Brachypodium distachyon germplasm is almost finished. This work relates to the parent project by providing phenotypic data about natural populations that is used to achieve the objectives of the parent project more rapidly. We completed phenotyping a collection of 500 homozygous T-DNA lines and are currently analyzing the data. We selected two T-DNA lines for detailed genetic analysis and have demonstrated that the T-DNA is genetically linked to the observed phenotype. We created DNA constructs containing the wild-type gene and are inserting these constructs into the mutants in order to show complementation. This is the final step to definitively demonstrate that the T-DNA insertion is responsible for the observed phenotype. These efforts are creating a valuable genetic resource that will allow researchers to gain the information necessary to use a predictive approach to create improved crop varieties.