Читать книгу Wheat - Peter R. Shewry - Страница 49

Wheats can be described as red or white based on the intensity of red pigmentation in the seed coat (Lachman et al. 2017). Seed coat colour is largely determined by homologous genes at the R‐1 loci on the long arms of the group 3 chromosomes (i.e. R‐A1, R‐B1, and R‐D1). Red cultivars carry one or more of the red (dominant) alleles and the intensity of pigmentation increases as gene dosage increases to three (Flintham 2000). Most American and European wheats are red. This is because the red seed coat is associated with greater resistance to PHS (Mares et al. 2009; Ji et al. 2018). By contrast, white wheats are more suited to areas that are dry during ripening and harvest and are favoured for the manufacture of certain types of flat bread, steamed breads, and noodles. White wheats can also be used to produce a higher extraction rate of flour during milling without products becoming discoloured with bran flecks (Hatcher et al. 2006).