Physiological Factors Underpinning Grain Yield Improvements of Synthetic‐Derived Wheat in Southwestern China

Abstract

ABSTRACTSynthetic hexaploid wheat (SHW) is a valuable source of genetic diversity for germplasm enrichment in wheat breeding. In China, SHW‐derived material has shown significant yield increases. A 3‐yr field experiment at Guanghan and Jiangyou in the Sichuan Basin of China was conducted to characterize the potential of three SHW‐derived cultivars (SDCs) with five local elite nonsynthetic‐derived cultivars as checks (NSCs). On average, SDCs showed an 11.5% or 951 kg ha−1 yield increase compared with NSCs. This yield gain was mainly attributed to increases in both grain number m−2 (5.7%) and thousand kernel weight (5.9%). A higher rate of aboveground dry matter accumulation, especially in the early growth stages, was observed in the SDCs. The SDCs also had better partitioning to the grain, as evidenced through an increased harvest index (HI). The SDCs had a relatively compact and erect plant type with medium and upper leaves having a mean extinction coefficient at 45° (EC45°) increase of 8.4% above the NSCs at 20‐d after flowering. Correlations between grain yield components and physiological traits were analyzed. We concluded that the use of SHW has the potential to significantly increase wheat yield grown under rain‐fed environments with low photosynthetically active radiation.