GAR dwarf gene Rht14 reduced plant height and affected agronomic traits in durum wheat (Triticum durum)

Abstract

The GA-insensitive dwarf genes, Rht-B1b (Rht1) and Rht-D1b (Rht2), have been used worldwide for reducing plant height, improving lodging resistance and grain yield since the Green Revolution. To explore new dwarf genes for wheat improvement, in this study, the effects of GA-responsive (GAR) dwarf gene, Rht14, on plant height related traits, agronomic traits, yield traits and quality traits were evaluated in durum wheat by F2:3 lines, F3:4 lines and F4:5 lines that derived from reciprocal crosses between the Rht14 donor Castelporziano (CP) and Langdon (L). These results indicated that Rht14 could reduce plant height by an average of 26.68 % and 27.68 % in the lines of CP × L and L × CP populations, respectively. Furthermore, both the length of peduncle and each internode were all significantly reduced, with the basal one as the most proportion and the peduncle as the largest difference. The flag leaf length, width and area increased significantly in dwarf lines. Rht14 did not affect most of the yield components, including number of tillers plant−1, number of fertile tillers plant−1, spikelet number spike−1, grain number spike−1, biomass plant−1, grain yield plant−1, while significantly decreased 1000-kernel weight. Rht14 didn’t affect the length of coleoptile and seedling root traits when compared with tall lines, indicating it may have the potential for good seedling establishment in the field. A negative effect of Rht14 on some quality traits was observed. The results indicate that GAR dwarf gene Rht14 represents a new alternative locus in breeding programs for improving population yield potential and lodging resistance in wheat.