Abstract:

Based on the Open-Top Chamber (OTC) experiment platform at Dingxi Arid Meteorology and Ecological Environment Experimental Station of Arid Meteorology Institute of China Meteorological Administration, an experiment was conducted to investigate the effects of elevated CO2 concentration (370 μmol·mol-1 (CK), 460 μmol·mol-1 and 550 μmol·mol-1) on growth, development and yield of spring wheat . The results are as follows: with the increase of CO2 concentration, the air temperature and relative humidity above spring wheat canopy increased, while the soil temperature at 10 cm depth decreased and the shallow soil water content increased in semi-arid area. Under CO2 concentrations with 460 μmol·mol-1 and 550 μmol·mol-1, the growth and development of spring wheat were accelerated, and the whole growth period was shortened by 2-4 days. The rise of CO2 concentration could obviously promote the increase of plant height, leaf area index and chlorophyll content of spring wheat, and the increase magnitudes of plant height and leaf area index were largest during the flowering stage, while the chlorophyll content increased significantly from the late grain filling stage to milk ripe stage. Panicle length, panicle weight, spikelet number, grains per panicle, grains weight per panicle, 1 000-grain weight and yield increased, while sterile spikelet number, spikelet sterility rate and harvest index showed downward trend with the increase of CO2 concentration. The grain yield of spring wheat under 460 μmol·mol-1 and 550 μmol·mol-1 concentrations respectively increased by 8.88% and 19.93% than CK (370 μmol·mol-1). The research can provide the theoretical references for the sensitivity and adaptability of spring wheat in semi-arid area of China under global climate change.

Key words: elevated CO2 concentration, spring wheat, growth and development, yield, semi-arid area

摘要：

利用典型半干旱区定西试验基地的开顶式气室(Open-Top Chamber，OTC)研究平台，以春小麦“定西24号”为供试品种，设置对照（370 μmol·mol-1）和增加90 μmol·mol-1（460 μmol·mol-1）、180 μmol·mol-1（550 μmol·mol-1）3个CO2浓度梯度，研究大气CO2浓度升高对半干旱区春小麦生长发育、产量及产量构成因素的影响。结果表明：CO2浓度升高使春小麦冠层空气温度和相对湿度增加，10 cm深处的土壤环境温度降低，春小麦根际浅层的土壤湿度增加；CO2浓度增高，春小麦发育加快，生育期相应提前，全生育期缩短2～4 d；CO2浓度升高对春小麦株高、叶面积指数和叶绿素含量有明显促进作用。其中，株高和叶面积指数在开花期增幅最大，叶绿素含量在灌浆后期到乳熟期增加更为显著；随着CO2浓度升高，穗长、穗重、小穗数、穗粒数、穗粒重、千粒重、产量均呈增加趋势，而无效小穗数、不孕率以及收获指数则呈下降趋势，在460 μmol·mol-1和550 μmol·mol-1浓度下，籽粒产量分别比对照提高8.88%和19.93%。

关键词: CO2浓度升高, 春小麦, 生长发育, 产量, 半干旱区