The effect of dwarfing genes in spring wheat in dry environments, 1. Agronomic characteristics

摘要: Near-isogenic lines of wheat were used to investigate the possible yield penalty dwarfing genes in rainfed environments. Field experiments conducted over seven years south-eastern Australia which characterized by drought becoming progressively more intense as crop maturity approached. Isogenic sets for Rht1 and Rht2 chosen cover a range heights tall (rhtrht) lines, from 100 130 cm when grown absence before anthesis. or reduced this height about 23% whereas together Rht3 alone ceiling 47%. Highest grain yields achieved with between 70 cm. Although major usually required achieve optimum height, no specific advantage was found. Likewise, short isogenic populations, populations yielded than even though they all contained Rht1. The expression their effect on agronomic characteristics varied depending genetic background but general trends evident. Above-ground dry weight 4.4% mean each 10 reduction below Above there little change above-ground weight. Harvest index decreased 3.7% value increase above 65 When less cm, harvest remained constant. Kernel number sensitive variation kernel In only one evidence compensation weight; four sets, both matched positive way.