低水多变环境下玉米叶片的光合与反射光谱特征

采用盆栽试验，以玉米品种苏玉19为试材，在每次复水第7天同时测定不同处理植株的生物量、根冠比、叶绿素荧光、气体交换以及光谱特征等指标。结果表明，持续干旱处理抑制植株生长，增加根冠比，并通过气孔限制和非气孔限制因素抑制光合作用。持续干旱处理幼苗的mSR705、chlNDI和REP均显著小于对照，但对SIPI的影响不显著。多变低水环境下玉米幼苗生长明显受到抑制，但根冠比、叶绿素荧光、气体交换以及光谱特征等指标与正常供水没有差异。可见，生物量分配、光合作用和光谱特征的维持可能是玉米适应多变低水环境的重要生理机制。

Properties of photosynthesis and spectral reflectance in leaves of maize under the low and variable water conditions

The present study was carried out to examine the effects of low and variable water conditions on plant biomass, root to shoot ratio, chlorophyll fluorescence, gas exchange and spectral features in leaves of maize (Zea mays cv. Suyu 19) by pot experiment. The results showed that continuing drought led to an inhibition of plant growth, increase of root to shoot ratio, and inhibition of photosynthesis through stomatal and/or non stomatal limitations. The mSR705, chlNDI and REP were also significantly reduced by continuing drought compared to the controls, whereas SIPI was unaffected. Under the low and variable water conditions, plant growth was inhibited, however, the root to shoot ratio, chlorophyll fluorescence, gas exchange and spectral properties were similar to the controls. The results indicated that the maintenance of biomass allocation, photosynthesis and spectral reflectance might be an important mechanism for maize to adapt the low and variable water conditions.