不同水分利用效率的高羊茅水分和光合特性研究

THE STUDY OF WATER AND PHOTOSYNTHETIC CHARACTERISTICS OF TALL FESCUE WITH DIFFERENT WATER USE EFFICIENCIES

选用高羊茅不同水分利用效率的遗传材料，利用盆栽试验对其水分和光合特性进行了研究，旨在揭示其水分利用效率差异的原因。结果表明，高水分利用效率品系有较好的水分关系且抗旱，其气孔导度较低，水分利用效率高。高、低水分利用效率品系的净光合速率无差异。造成以Ａ／Ｅ或Ａ／ＧＣＯ２表示的水分利用效率差异的根本原因在于叶肉细胞光合活性的差别。比叶片重、以面积表示的叶绿素含量和细胞内ＣＯ２浓度均可作为衡量水分利用效率大小的良好指标。

In order to reveal the cause of water use efficiency (WUE) difference, water and photosynthetic characteristics of Tall Fescue genetic materials with different WUE were studied in pot experiment. Results showed that, high WUE accessions had favourable water relation and were more drought-resistant, meanwhile,their stomatal conductance were lower and WUE were higher. No net photosynthetic rate difference was existed in high and low WUE accessions. The radical cause of WUE difference attributed to mesophylic photosynthetic capacity. Specific leaf weight, chlorophyll content (expressed in area) and internal CO 2 concentration Ci could be used as valid indexes for WUE evaluation.