Nondestructive Screening for Oleic and Linoleic Acid in Single Sunflower Achenes by Near-Infrared Reflectance Spectroscopy

Current breeding programs dealing with the modification of oleic and linoleic acid concentrations in sunflower (Helianthus annuus L.) require large numbers for chromatographic analyses of half seeds. The objective of this research was to study the potential of near-infrared reflectance spectroscopy (NIRS) to estimate the oleic and linoleic acid concentrations of intact single sunflower achenes. Spectra from intact achenes were collected with a specially designed adapter and a standard monochromator instrument. Calibration equations for oleic and linoleic acid were developed from a calibration set including 465 intact achenes with a large range of variation for both fatty acids and were validated with an external set of 100 intact achenes. The coefficient of determination between NIRS and gas-liquid chromatography (GLC) was 0.88 for both fatty acids in external validation, demonstrating the high reliability of NIRS to predict oleic and linoleic acid concentrations of intact, single sunflower achenes. The calibration equation for oleic acid was used to evaluate two [F.sub.2] populations segregating for this fatty acid, which were further analyzed by GLC. The use of NIRS predictions permitted the discrimination of the majority of the high oleic acid achenes ([is greater than] 700 g [kg.sup.-1]), demonstrating the use of NIRS for selecting sunflower achenes with specific oleic and linoleic acid concentrations.
The availability of rapid, nondestructive methods to evaluate seed quality traits is one of the most important factors determining the success of plant breeding projects (Robbelen, 1990). In oilseed crops, [...]