BREEDING DURUM-WHEAT FOR PASTA QUALITY IN CANADA (REPRINTED FROM WHEAT - PROSPECTS FOR GLOBAL IMPROVEMENT, 1998)

Canada was the largest durum wheat (Triticum turgidum var durum) produ cer in 1994, and in recent years supplied over 70% of world export tra de in durum. Breeding for pasta quality is, therefore, a primary objec tive in Canadian durum breeding programs. Control of cultivar registra tion and stringent grading standards ensure that durum of consistent h igh quality is produced for domestic and export markets. The objective s of breeding programs include: improvement of traits related to produ ction concerns, such as grain yield, disease resistance and sprouting resistance, and those related to end-use quality, such as protein conc entration and quality; milling quality factors, such as semolina yield ; colour of the wheat, semolina and pasta; and cooking quality. Select ion and testing for quality begins at very early generations and becom es more stringent for advanced inbred lines. Selection is practised at the F-1 or F-2, where appropriate, using monoclonal antibodies to ide ntify desirable gamma gliadins (gamma-45) or low molecular weight glut enin subunits (LMW 2) that have been shown to be related to end-use qu ality. Grain from early generation yield trials, starting at F-4, is s creened for protein concentration and pigment content by Near Infrared reflectance, and for gluten strength by sodium dodecyl sulphate (SDS) sedimentation and micro-mixograph. Promising lines entered into multi -location yield trials are screened with more time-consuming procedure s to fully assess suitability for pasta processing. These tests includ e semolina yield, ash and colour, and predictions of gluten strength s uch as mixograph and alveograph, and cooking quality. Candidate cultiv ars with quality equal to or better than the mean of the check cultiva rs can be proposed for registration after three years in the Durum Coo perative Test. It takes approximately 10 years from performing a cross to registrating a new cultivar.