Plant materials
This study was conducted using six DH populations derived from the following crosses: Bethlehem/Westonia (BW); Spitfire/Mace (SpM); Spitfire/Bethlehem (SpB); Gregory/Bethlehem substitution line 7AS (G7A); Suntop/Bethlehem substitution line 3BL (St3B); and Spitfire/Bethlehem substitution line 7AS (Sp7A). Spitfire produces relatively good yield with high protein content, whilst Westonia is a medium-yielding variety with low protein content. Mace is a high-yielding variety with medium protein content, whilst Suntop produces medium yield with high protein content. Gregory is well adapted to a wide range of environments and produces medium grain yield with high protein content, whilst Bethlehem and Bethlehem substitution lines 3BL and 7AS tend to have high protein content with medium to high yield (Supplementary Table 1). The population sizes of the six DH populations were 105, 327, 304, 168, 222, and 350 for BW, G7A, Sp7A, SpB, SpM, and St3B, respectively (Supplementary Table 2). The wheat varieties Wyalkatchem, Tungsten and Yitpi were included as internal controls in the 2018 field trials. Wyalkatchem is an early-flowering, high-yielding variety in Western Australia (Supplementary Table 1 and 3). Both Tungsten and Yitpi are late-flowering and are considered high-yielding varieties in high rainfall seasons (Supplementary Table 1 and 3). The genotypes of 171 historical lines were used to investigate the proportion of mutatedVrnA1a , VrnB1a , VrnD1a , Rht1 and Rht2genes bred into those lines (described in Supplementary Table 4).