Abstract: 【Objective】Synthetic hexaploid wheat (SHW) has increasingly reported having outstanding tolerance to abiotic and biotic stresses and a great potential in improving wheat yield. The objective of this study was to evaluate the yield performance, accumulation and portioning of dry matter, leaf and canopy photosynthesis of SHW-derived varieties released nationally. 【Method】Three SHW-derived varieties (SDVs) were compared with 5 local elite non-synthetic derived varieties (NSVs) in field experiments conducted during the 2010 to 2011, 2011 to 2012, and 2012 to 2013 crop seasons at Guanghan county of Sichuan province, China. 【Result】Combined analysis of variance showed that a significant difference in grain yield and dry matter-related traits was detected among genotypes and experimental years, and year effect was higher than both genotype effect and genotype by year interaction. Average grain yield，grain number/m2, and thousand kernel weight of SDVs over three years were 9 163 kg•hm-2, 19133, and 47.5 g, respectively, which were 12.31%, 5.31%, and 7.95% higher than NSVs. SDVs had higher rate of dry matter accumulation, especially at earlier growth stages as showed that the rates of dry matter accumulation during the periods from sowing to tillering and from tillering to jointing were 18.66% and 20.46% higher than NSVs, and consequently higher amount of accumulated dry matter at major growth stages, higher translocated dry matter and contribution to grain than NSVs. With no significant difference in dry matter distribution amongst organs of spike-bearing shoot between SDVs and NSVs at flowering stage, while the proportion of dry matter to leaf, rhachis & glume, and stem & sheath of SDVs was lower than that of NSVs by 15.46%, 7.14%, and 2.65%, respectively. SDVs showed a relative compact type with medium to high plight, shorter but wider upper leaves compared to NSVs, and no significant difference in canopy analyzer parameters between varieties tested at anthesis but SDVs had significantly lower transmission coefficient for radiation penetration and higher Extinction coefficient than that of NSVs at mid-grain filling stage. SDVs displayed prominent canopy photosynthesis at anthesis and 20 d after anthesis and higher SPAD values of flag- and penultimate leaf during whole grain filling period. Grain yield showed a significant positive correlation with grain number per m2, SPAD values of flag- and penultimate leaf after flowering, and canopy photosynthesis at mid-grain filling stage. 【Conclusion】 Compared to NSVs, SDVs had higher grain number per m2 and kernel weight, higher crop growth rates at early stages and amount of accumulated dry matter with more partitioning to grain, relatively compact plant type with longer green-stayed period and higher capacity of canopy photosynthesis.

Key words: synthetic hexaploid wheat-derived variety , production and accumulation of dry matter , canopy , photosynthesis