不同耐旱型玉米自交系冠层光合及产量对生殖生长期干旱胁迫的响应

在PVC管栽和大田条件下，采用裂区试验设计，主区为玉米自交系、裂区为水分处理，测定玉米冠层光合和产量等指标。结果表明，与对照(CK)相比，干旱胁迫(WS)处理下冠层叶色值(SPAD)、光合速率(Pn)、蒸腾速率(Tr)和叶面积指数(LAI)均呈下降趋势，耐旱性较强的黄早四(HZS)平均降幅小于耐旱性较弱的CML58，其SPAD和LAI的降幅较高期(R3)出现早于CML58(R5)；干旱胁迫后，水分利用效率(WUE)呈升高趋势，HZS平均升幅高于CML58。HZS的SPAD、Pn、Tr、WUE、LAI、单株粒重、收获指数和群体产量均高于CML58。与CK相比，WS处理下HZS群体产量平均降幅低于CML58。综上，耐旱性较强的玉米自交系冠层光合参数对生殖生长期干旱胁迫响应相对滞后，可在干旱胁迫后维持相对较高的光合性能、水分利用效率和叶面积指数，促进植株干物质转化与子粒建成，最终获得较高产量。

Response of Canopy Photosynthesis and Yield of Corn Inbred Lines with Different Drought Tolerance to Drought Stress at Reproductive Growth Stage

The canopy photosynthesis and yield of corn were measured at PVC pipe planting and field condition using split plot experiment design. The main plots were 2 corn inbred lines and the split plots were 2 water treatments. The results showed that compared with CK treatment, the canopy SPAD, Pn, Tr and LAI decreased at WS treatment. The average decrease ranges of HZS inbred line with higher drought tolerance was less than that of CML58 inbred line with lower drought tolerance, the higher decreasing period(R3) of SPAD and LAI appeared earlier than that of CML58(R5). The WUE of the two inbred lines increased after drought stress, and the average increase range of HZS was higher than that of CML58. The SPAD, Pn, Tr, WUE, LAI, grain weight per plant, harvest index and yield of HZS were all higher than those of CML58. Compared with CK treatment, the average yield decrease range of HZS at WS treatment was lower than that of CML58. In conclusion, the response of canopy photosynthetic parameters on corn inbred line with higher drought tolerance was relative lag behind to drought stress at reproductive growth stage, which could maintain relatively high photosynthetic performance, water use efficiency and leaf area index after drought stress, and promoted dry matter transformation and kernel formation of plant, and obtained higher yield finally.