关键词: 播期, 播期

Abstract: In order to provide a theoretical basis for spring wheat high-yield cultivation under enriched CO₂ condition, a free-air CO₂ enrichment (FACE) experiment with spring wheat variety Dingxi 24 was carried out in 2010 in Dingxi of Gansu province, and then grain filling characteristics and yield formation of spring wheat under different CO₂concentration were analyzed. The results showed that the dry matter accumulation and 1000-grain weight increased significantly，the dates corresponding to maximal dry matter accumulation rate and grain filling rate were delayed，maximal dry matter accumulation rate and grain filling rate increased with the increase of CO₂ concentration. Under different CO₂ concentrations, the correlation coefficient between grain weight and grain filling rate was significant at 0.01 levels, but the correlation coefficient between grain weight and grain filling duration was not significant，which mean that improving grain filling rate was more effective than extension of grain filling duration time to increase grain weight. For the three stage of grain filling, duration and filing rate of slow-increase period had more positive impact on the 1000-grain weight. The grain yield of spring wheat were increased by 15.62%, 29.42% and 36.98% than CK (370μmol/mol) in three high CO₂ levels (470, 570 and 670μmol/mol), and grain yield of spring wheat were significantly correlated with CO₂ concentrations (P<0.01). In this trial, the increase of grain yield mainly due to obvious increase of the grain number per ear.