CAJ | 학술논문

2011年6-9月在中国气象局河北固城生态试验站借助大型电动式防雨棚及人工灌溉，开展水分影响夏玉米生长发育的田间试验。首先进行夏玉米叶片光合作用日变化和光合作用光响应曲线的观测，然后利用不同模型拟合光响应曲线确定最适模型并提取光合特征参数，探讨土壤水分条件对不同生育时期夏玉米叶片光合特性的影响规律。结果表明：土壤水份适宜时，玉米抽雄期的光合能力最强，重度干旱时，抽雄期的光合能力降低幅度也最大，其次为乳熟期、拔节期；直角双曲线修正模型最适合描述干旱环境下的玉米光合能力光响应过程，轻度干旱使各生育时期光饱和点及最大净光合速率下降，而对光补偿点量子效率和光补偿点的影响不明显；重度干旱下各生育时期光饱和点、最大净光合速率较轻度干旱又进一步下降，同时各生育时期光补偿点量子效率也有明显下降，而光补偿点明显上升，表明玉米叶片的强光利用能力对干旱敏感，而它的弱光利用能力对干旱响应较迟钝。
2011년6-9월재중국기상국하북고성생태시험참차조대형전동식방우붕급인공관개，개전수분영향하옥미생장발육적전간시험。수선진행하옥미협편광합작용일변화화광합작용광향응곡선적관측，연후이용불동모형의합광향응곡선학정최괄모형병제취광합특정삼수，탐토토양수분조건대불동생육시기하옥미협편광합특성적영향규률。결과표명：토양수빈괄의시，옥미추웅기적광합능력최강，중도간한시，추웅기적광합능력강저폭도야최대，기차위유숙기、발절기；직각쌍곡선수정모형최괄합묘술간한배경하적옥미광합능력광향응과정，경도간한사각생육시기광포화점급최대정광합속솔하강，이대광보상점양자효솔화광보상점적영향불명현；중도간한하각생육시기광포화점、최대정광합속솔교경도간한우진일보하강，동시각생육시기광보상점양자효솔야유명현하강，이광보상점명현상승，표명옥미협편적강광이용능력대간한민감，이타적약광이용능력대간한향응교지둔。
The field experiment of drought on summer maize growth is carried out by using large electric water proof and irrigation installations.First of all,the diurnal variations of photosynthesis and photosynthesis-light response curves of summer maize leaves are measured.And then,the different models are used to fit light response curve to determine the optimal model and extract the photosynthetic parameters.Finally, the impact of soil moisture on the photosynthetic characteristics of summer maize leaves at different growth stages is discussed.The comparison of light response curve fitting by different models shows that compa-ring to the non-rectangular hyperbolic model and exponential model,the simulation result of modified rec-tangular hyperbola model is better.In particular,it can effectively simulate the downward trend of light saturated net photosynthetic rate with light intensity increased,which is more common under drought con-ditions.In addition,the use of modified rectangular hyperbola model can extract the quantum efficiency of the light compensation point which is the numerical uniqueness indicator of evaluation of crop light use. The photosynthetic parameter analysis shows that both light saturation point (LSP )and maximum net photosynthetic rate (Pmax)decline in different growth stages,and quantum efficiency of light compensation point (CQY)and light compensation point (LCP)are insignificantly affected under slight drought.With the aggravation of drought,LSP andPmax has a further decrease and CQY has a significant decline while LCP had a great increase under severe drought condition.The comparison of different growth stages show that LSP andPmax decline largest in jointing stage,second in tasselling stage and least in milky maturity stage under slight drought.LSP andPmax decrease by 24.1%to 43.7%and 9.3%to 46.1%.LSP andPmax decline largest in tasselling stage,the second in milky maturity stage,the least in jointing stage under se-vere drought.LSP andPmax decrease by 12.3%to 33.6%and 48.5%to 62.2%.In addition,observations show that photosynthetic and transpiration rate of summer maize leaves at different growth stages both de-cline under drought.The comparison of different growth stages show that photosynthetic and transpiration decline largest in tasselling stage,second in jointing stage and least in milky maturity stage under slight drought.With the aggravation of drought,photosynthetic and transpiration still decline largest in tassel-ling stage,but second in milky maturity stage,and least in jointing stage.Water use efficiency of maize leaves at different growth stages are relatively large under suitable soil water condition (2.8-4.5μol· mmol-1 ),and slight drought (2.6-4.2μol·mmol-1 ).Relative to tasselling and milky maturity stage, water use efficiency of maize leaves in jointing stage is the largest.