Vigorous responsiveness of dwarf gene Rht14to exogenous GA3evaluated on important morphological and agronomic traits in durum wheat

Rht14, was considered as a GA‐responsive dwarf gene in durum wheat (Triticum durumL.). The object of this paper is to understand the responsiveness of Rht14after applying exogenous GA3on important morphological and agronomic traits, and its potential application in wheat breeding. In this study, the F2:3lines, F3:4lines and F4:5lines derived from the reciprocal crosses between the Castelporziano (CP), the donor of Rht14, and tall cultivar Langdon (L) were used to evaluate the effects of Rht14with exogenous GA3application on crucial traits. After application of GA3, the plant height of the dwarf lines was more significantly increased by an average of 51.21% and 52.27% than that of the tall lines by 14.70% and 15.16% of the two populations, respectively, while their diameter and thickness of internodes were remarkably reduced, and their flag leaf area, SPAD value and net photosynthetic rate were markedly decreased, compared with the controls. After application of GA3, the spikelet number spike−1, grain number spike−1, and 1000‐kernel weight of the dwarf lines notably increased, while no significant differences were observed on the seed length, width and thickness. Exogenous GA3significantly increased the coleoptile length, whereas notably reduced the max root length and total root length of the dwarf lines. Significant increases of crude protein, wet gluten, sedimentation value, stability time and development time were observed in the dwarf lines treated with GA3. This study indicated the dwarf gene Rht14was a GA‐deficient gene and application GA3could rescue some negative effects by Rht14.