Physiological factors underpinning grain yield improvements of synthetic derived wheat in South Western China
Yonglu Tang; Rosewarne, G.M.; Chaosu Li; Xiaoli Wu; Wuyun Yang; Chun Wu.
Synthetic 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 three year 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 non-synthetic derived cultivars as checks (NSCs). SDCs showed on average an 11.5% or 951 kg ha-1 yield increase as compared to 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 above-ground 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 EC45° increase of 8.4% over 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.