土壤水分胁迫对玉米形态发育及产量的影响

未来气候变化可能加剧的干旱化将对我国主要粮食和最重要的饲料作物玉米产生严重影响。为增进玉米对干旱化响应与适应的理解及制定应对策略 ,利用大型活动遮雨棚及池栽对玉米进行了全程水分控制试验研究。对不同土壤水分胁迫下的玉米形态表征、生长发育及产量的分析表明 ,玉米受干旱胁迫的影响程度因受旱轻重、持续时间以及生育进程的不同而不同 ,受旱越重 ,持续时间越长 ,影响越甚。大喇叭口期前 ,玉米株高和生物产量受有限供水或轻度干旱影响不算很大 ,但从大喇叭口期后直至抽雄和灌浆期 ,轻度干旱胁迫持续久了也会对株高和生物产量产生较大不良影响。严重干旱胁迫则从拔节始至灌浆期均对株高和生物产量影响更为不利。进而引起果穗性状恶化 ,穗粒数和百粒重减小 ,最终导致经济产量大幅下降。说明玉米生育前期(大喇叭口期前 )进行有限的控水可行。而玉米生育前期干旱胁迫将使生育进程明显延缓 ,严重干旱胁迫可使抽雄、吐丝期较水分充足滞后 4 d左右 ,并引起成熟期推迟

Effects of soil water stress on morphological development and yield of maize

Aridification might be enhanced under climatic change in the future, and it might seriously affect maize, one of main food and the most important forage crop in China. Understanding the possible responses of maize to drought is very important for making scientific strategies in order to mitigate negative effects of climatic change. Thus, simulating experiment on the responses of maize (Zea mays) to different soil water stress levels was conducted by pond cultivation at neutral loam, meadow soil. The soil water levels were designed as three levels by relative water content (RWC): 75 %( control, full water supply or well-watered), 55 %( moderate water stress) and 35 %( severe water stress) from maize seedling to maturity by controlling irrigation and the mobile rain shelter. The morphological characteristics, growth, development and yield of maize under different soil water levels and different growth stages would be analyzed in this paper. The results indicated that the intensities of the drought stress effects on maize rely on its drought intensity, drought duration and growth stage. The longer and more severe the water stress is, the more serious the effects on crop are. Moderate water stress would not change significantly its plant height and biomass production before the big flare period of maize; however, it would seriously decrease its height and biomass from big flare to tasselling as well as filling periods. Severe water stress would seriously affect its height and biomass production from shooting to filling periods. It would deteriorate its ear characteristics, and decrease significantly ear kernel number and 100-kernel weight as well as economic yield of maize. It implied that limited controlling water (moderate water stress) is feasible before big flare period of maize. The results also showed that drought stress before big flare period of maize would postpone obviously growth process of maize. Especially, severe water stress would delay 4 days or so for tasselling and silking stage compared to that under control treatment, and resulted in the postponement of its maturation.