The overall goal is to develop improved avocado germplasm suitable for HD production by integrating traditional and molecular breeding. For the duration of this project we will focus on tree size and form, two traits that are critical for the success of HD production.1) TRAIT DISCOVERY: A recurrent approach to avocado phenotyping that uses traditional descriptors of tree architecture but expands by a preferential focus to the subunits (i.e. single shoots and branches) that develop the tree form through time. The suite of traits will be identified and measured the first year and refined in year two.2) PHENOMICS: Apply a quick and reliable high-throughput data acquisition method to acquire measurements for the seasonal suite of phenotypical traits defined in objective 1 across a large MP. Methods will include a video imaging system that can dynamically store several layers of information for post-processing outside the field setting and can yield quantitative over qualitative information.3) GENOTYPE MAPPING POPULATION: Genotype every member of the MP at genetic variants that segregate between the parental varieties using whole genome resequencing.4) INTEGRATE GENOMIC AND PHENOMIC DATA: Identify quantitative trait loci (QTL) responsible for variation in shoot traits and tree form. Genetic markers associated with large-effect loci will be integrated into the breeding program to expedite the selection of hybrids with promising canopy characteristics.