Abstract
High-throughput phenotyping (HTP) has the potential to revolutionize
plant breeding by providing scientists with exponentially more data than
was available through traditional observations. Even though data
collection is rapidly increasing, the optimum use of this data and
implementation in the breeding program has not been thoroughly explored.
In an effort to apply HTP to the earliest stages of a plant breeding
program, we extended field-based HTP pipelines to evaluate and extract
data from spaced single plants. Using a panel of 340 winter wheat lines
planted in full plots and grid-spaced single plants for two growing
seasons, we evaluated relationships between single plants and full plot
yields. Normalized difference vegetation index (NDVI) was collected
multiple times through the growing season using an unmanned aerial
vehicle. NDVI measurements during grain filling stage from both single
plants and full plots were typically positively associated with their
respective grain yield with correlation ranging from -0.22 to 0.74. The
relationship between single plant NDVI and full plot yield, however, was
variable between seasons ranging from -0.40 to 0.06. A genome wide
association analysis (GWAS) identified the same significant markers for
traits measured in both full plots and single plots, but also displayed
variability between growing seasons. Strong genotype by environment
interactions could impede selection on quantitative traits, yet these
methods could provide an effective tool for plant breeding programs to
quickly screen early-generation germplasm especially for qualitative
traits. Effective use of early-generation, affordable HTP data could
improve overall genetic gain in plant breeding.