Effects of different Rht-B1b, Rht-D1b and Rht-B1c dwarfing genes on agronomic characteristics in wheat

The value of different dwarfing genes in winter wheat breeding was studied using 6 near-isogenic lines carrying different Rht dwarfing genes over three years experiment. Results showed that both the Rht-B1b and Rht-D1b semi-dwarfing genes had significantly positive effects on kernel number and grain weight per spike, and had significantly negative effects on 1000-grain weight comparing to the tall line ( Rht-B1a ). The Rht-B1c dwarfing gene had a significantly negative effect on kernel number per spike, and had positive effect on 1000-grain weight. The combination of the Rht-D1b and Rht-B1c gene showed significantly negative effect on yield components. All of these 5 dwarfing or semi-dwarfing genotypes mentioned above had significantly negative effect on plant height and no significantly effect on the area of flag leaf, spikelets per spike and spike length