Variability in grain protein in Australian hexaploid wheats

Abstract

Grain protein content and grain yield data were collected from 11 Interstate Wheat Variety Trials (IWVT) and other sources. The level of variation in grain protein content beyond that attributable to covariation in environment and yield was estimated using a generalized linear model. A range of almost 4% in corrected protein content was found among 204 lines tested in IWVT. The Western Australian cv. Tincurrin was approx1% lower in grain protein content than any other line, while Shortim, Sun 43A, QT2200-20, QT2612-1 and Sun 92A were all 1.4-1.7% higher than the pooled mean of 4 control cultivars (Cook, Eagle, Halberd and Oxley). Accessions did not vary significantly in protein content with change in yield. Results from a range of other independent trials confirmed those from IWVT. Wheats genetically capable of producing a higher concentration of protein in their grain at a given yield level came principally from the Sydney University and Queensland breeding programmes, and those producing a lower concentration principally from Victoria and Western Australia. Grain hardness was independent of grain protein content and many low protein hard wheats entering the IWVT fell well outside current international market requirements.