Selection for protein content in soybean from single F₂ seed by near infrared reflectance spectroscopy: Selection protein by NIR in soybean

Soybean seed averages about 40% protein and is a dominant source of protein in animals and human foods. Increasing protein in soybeans is a goal in soybean breeding programs. Initial selection for protein among progeny from breeding populations is often based on non-destructive Near Infrared Reflectance (NIR) spectroscopy analysis of a 5 g or more seed sample in the F₃ or later generations. NIR spectroscopy analysis for protein on single F₂ seed would allow selection at the earliest possible time and improve selection efficiency for protein content; however this practice has not been evaluated. The objective of this study was to test effectiveness of NIR spectroscopy analysis of single F₂ seeds to select for increased protein content from two populations developed from high and average protein content parents. F₂ seeds from a single F₁ plant of each population showed a normal distribution with transgressive segregation for protein concentration. In both populations, F₃ seeds produced from plants from single F₂ seeds with either low or high protein content were analyzed for protein by NIR spectroscopy. Protein means and ranges of F₃ seed selected from high protein F₂ seeds were higher in protein than F₃ seed from low protein F₂ seeds which produced low means and ranges in protein content. This shows that analysis of single F₂ seed for protein content using NIR spectroscopy was effective in selecting for increased protein in the F₃ generation. Analysis of single F₂ seeds from breeding populations will improve breeding efficiency for protein in soybean breeding programs.