Daucus carota

Traits evaluated: LEAF TYPE (LEAFTYPE); MATURE LEAF LENGTH (MATLEAFLEN); MATURE LEAF WIDTH (MATLEAFWID); MATURE PETIOLE LENGTH (MATPETLENG); MATURE PETIOLE THICKNESS (MATPETTHK); PETIOLE HAIRINESS (PETIOLHAIR)

Evaluation location: Iowa, United States. Method: Daucus descriptor data recorded from observation planting at the NCRPIS farm (42 degrees 3 minutes N latitude 93 degrees 30 minutes W longitude).

This study was designed to estimate ion leakage and increase in cell permeability in response to heat stress at the early and late seedling developmental stages of 215 diverse accessions of wild and cultivated carrot germplasm.

The objectives of this study were to evaluate the response of diverse carrot germplasm to heat stress, identify heat-tolerant germplasm that may be used by plant breeders, and define the appropriate temperature for assessing heat tolerance in germinating carrot seed.

This study is the first field-based, multi-year experiment to evaluate shoot-growth trait variation over a 100-day growing season in a carrot diversity panel (N=695) that includes genetically diverse carrot accessions from the United States Department of Agriculture National Plant Germplasm System. This study provides the first broad-sense heritability estimates for early-season seedling vigor and early-season canopy coverage on a diverse collection. We also develop a method for characterizing flowering to identify accessions that are predominantly biennial, which could be incorporated into biennial breeding programs without substantially increasing the risk of annual growth habits.