Genetic Mapping of Yield and Normalized Difference Vegetative Index (NDVI) in Soft Red Winter Wheat (Triticum aestivum L.).

Remote sensing is widely used as a tool to monitor crop growth and performance. Measurements of canopy spectral reflectance have proven to be a useful tool for yield and biomass prediction, particularly in abiotic stressed environments such as conditions of drought, heat and soil waterlogging. In wheat, normalized difference vegetative index (NDVI) is commonly used as a non-subjective, non-destructive tool to monitor plant health and vigor. The objective of this research was to determine the utility of NDVI as a tool for biomass and yield prediction in wheat across multiple environments with varying yield potential and to identify quantitative trait loci (QTL) for yield, yield components and NDVI. A population of 157 wheat recombinant inbred lines derived from a cross between Pioneer 26R61 (Pioneer Hi-Bred) and AGS 2000 (University of Georgia) were grown over three years in 13 locations. NDVI measurements were taken periodically throughout the growing season from the early vegetative stage to physiological maturity. Vegetative biomass samples were harvested during early plant development and biomass and yield components were determined at maturity by harvesting 50 tillers at ground level. Results show significant genotypic differences across environments with principle component analysis identifying three strong environmental clusters.  Yield components showed strong correlations with total yield, ranging from 0.18 to 0.73. NDVI values varied amongst genotypes and throughout the growing season, with late-season NDVI measurements moderately correlated with total biomass and yield, ranging from 0.21 to 0.48. Preliminary quantitative trait loci analysis showed stable QTLs across environments with the variance explained ranging from 14 to 55%. Results of this study show NDVI to have potential as both a selection tool in wheat breeding programs and as an effective way for other researchers and producers to monitor their crop’s growth and development.