Kernel colour changes associated with field weathering of spring wheat.

Abstract

. Kernel colour changes associated with field weathering of spring wheat. Can. J. Plant Sci. 86: 371-377. The Canadian wheat-grading system is based on visual assessment to estimate end-use quality, both for assignment to classes and to grades within classes. Extensive training and experience are required to accurately interpret visual indicators of quality. Therefore, breeding programs are attempting to develop instrumental techniques to objectively measure visual characteristics of potential new cultivars. The objective of this research was to examine colour changes associated with field weathering of wheat cultivars from the Canada Western Red Spring, Canada Western Amber Durum, and Canada Prairie Spring Red and White classes of wheat, as measured with a portable colorimeter. The class means exhibited colour differences, although the large variability within classes suggests that, used in isolation, colour measurements would not be a satisfactory means of identifying the class of individual samples. Weathering caused an increase in L* (lightness), a decrease in a* (redness), and a slight increase in b* (yellowness), and the effects were similar for all classes. Severe weathering caused loss of vitreousness in addition to bleaching, and the colour measurements reflect the integrated colour changes associated with both effects. Within each class, although there were cultivar differences for colour, the cultivars responded similarly to weathering, suggesting that breeders should simply select lines which exhibit intense, desirable colour prior to weathering. Les obtenteurs s'efforcent donc de mettre au point des techniques instrumentales qui les aideront à quantifier objectivement les paramètres visuels des nouveaux cultivars éventuels. La présente étude avait pour but d'établir les variations de couleur associées à l'altération sur pied de variétés appartenant aux différentes classes de blé (blé roux de printemps de l'Ouest canadien, blé dur ambré de l'Ouest canadien, blé roux de printemps des Prairies et blé blanc) au moyen d'un colorimètre portatif. La couleur moyenne des différentes classes varie effectivement, mais la forte variabilité au sein de chaque classe laisse supposer qu'employés séparément, les relevés colorimétriques ne permettraient pas d'identifier de manière satisfaisante la classe des échantillons. L'altération sur pied entraîne une hausse de L* (luminosité), une baisse de a* (rouge) et une légère hausse de b* (jaune) dans toutes les classes. Une grave altération pourrait entraîner la perte de la vitrosité et le blanchiment du grain, de sorte que les valeurs reflèteraient le changement de couleur général associé à ces deux conséquences. Bien qu'ils présentent des différences de couleur, les cultivars de chaque classe réagissent de la même façon à l'altération sur pied, signe que les obtenteurs devraient se contenter de sélectionner les lignées ayant la couleur souhaitée la plus vive avant l'altération sur pied.

Effectiveness of an image-based sorter to select for kernel color within early segregating hard winter wheat (Triticum aestivum L.) Populations

“…Kernels harvested from the Dakota Lakes and Winner environment may have had better seed color contrast and produced better sorter calibrations. Several studies have demonstrated that disease, environmental stresses, and weathering, specifically weathering due to moisture, can significantly impact the expression of kernel color and the accurate differentiation of contrasting colors (Wu et al 1999;Matus-Cadiz et al 2003;McCaig et al 2006;Lukow et al 2013).…”

“…In a cross between a homozygous red parent with red alleles at all three loci, and a homozygous white parent, less than 2% of the F 2 progeny plants are expected to express white kernel color in the F 3 seed. Many other minor genes reportedly modify the expression of kernel color (Kumar et al 2009), and the environment will also significantly affect color (Matus Cadiz et al 2003;McCaig et al 2006;Lukow et al 2013). Cooper and Sorrells (1984) predicted that the best generation in which to select white kernels in a red/white cross was F 3 seed, given that many loci are likely to be segregating for yield.…”

Effect of Dark, Hard, and Vitreous Kernel Content on Protein Molecular Weight Distribution and on Milling and Breadmaking Quality Characteristics for Hard Spring Wheat Samples from Diverse Growing Regions

“…Therefore, the color class can determine wheat market price because both domestic and foreign buyers pay a premium for wheat of a preferred class. The grade reflects the variation in end‐use quality; in turn, the end‐use quality is affected by environment (McCaig et al 2006). Therefore, segregating based on the DHV kernel content would allow the flour milling and baking industry to choose between different subclasses of HRS wheat with varying DHV content for their intended end‐use applications.…”

Environment during grain filling affects pasta color

“…Reductions in test weight, vitreous kernel content, and falling number due to rainfall have been found in studies performed by Gan et al. (2000), McCaig, Gan, Clarke, Clarke, and DePauw (2006), and Ferrer, Weisz, Heiniger, Murphy, and Pate (2006). In addition, regression analysis performed in this study determined that total rainfall diminished vitreous kernel content and falling number (partial R 2 = .39 and .14, respectively) (data not shown).…”