Location: Vegetable Crops Research
Project Number: 5090-21000-073-103-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Aug 15, 2024
End Date: Jul 14, 2028
Objective:
Research and development objectives will focus on investigating the genetic mechanisms that control growth and development of carrot leaves and roots with a primary objective of determining the sequence and expression of a recently discovered gene that significantly influences carrot leaf growth, root size, and root color. An evaluation of this gene and other genes in the same family of genes will be evaluated in ARS carrot breeding program lines and diverse germplasm and gene expression will be characterized for key candidate genes. Similar genes in potato and cranberry will be identified. The sub-objectives are five-fold: 1) video phenotype plant growth in carrot genetic mapping populations and selected diverse germplasm; 2) genotype plants in genetic mapping populations segregating for carrot top and root growth; 3) perform transcriptome analysis in selected plants 4) perform marker - trait association analysis with related plant growth genes 5) intercross novel genes that influence growth rate into new carrot breeding lines.
Slow and variable plant growth and development creates significant reductions in carrot productivity and weed competitiveness, and researchers have reported wide variation in plant growth among a collection of cultivars. Based on these observations, carrot growers have included the identification of new gene sources of improved foliar and root growth as an area of critical importance for improving crop productivity and economic yield. The proposed work is critical because it will identify genes that contribute to production quantity and to carrot quality, thereby reducing grower inputs and improving consumer quality.
Approach:
Cooperator and ARS PIs will determine the map location and gene sequence of the newly-discovered gene; evaluate sequenced genomes from a large, diverse collection of carrot germplasm and breeding lines for the occurrence of this newly-discovered gene and related genes; perform transcriptome analysis to determine gene expression patterns and identify candidate genes by integrating gene annotation and comparative transcriptome analysis. Candidate marker gene analysis will be tested in the breeding program to select for more rapid plant growth.