干旱胁迫下臭椿4种源幼苗光合特性比较

Comparison of Photosynthetic characteristics for the Seedling of 4 Provenance of Ailanthus altissima under Drought Stress

设置4个土壤含水量水平W1、W2、W3、W4,分别为田间持水量的12.5%(严重干旱)、25%(中度干旱)、50%(轻度干旱)、75%(适宜含水量水平,CK),处理盆栽4个种源臭椿苗木,在苗木速生后期,采用英国C IRAS-1型便携式光合测定系统测定幼苗的光合特性。结果表明:在盆栽土壤干旱胁迫下,山东鲁中、河南宝丰种源的臭椿幼苗的净光合速率、蒸腾速率、瞬间水分利用效率和气孔导度均较高,表现出较强的抗旱特性,而宁夏平罗、北京密云种源幼苗的相应指标较低。

Four soil moisture including W, （severe drought）, W2 （moderate drought）, W3 （light drought）,W4 （favorable soil moisture, CK） were set up. W1 ,W2 ,W3 ,W4 constitute 12. 5%, 25% ,50%, 75% of field capacity respectively. Seedlings of 4 provenance of potted Ailanthus altissima were treated. In late fast-growing stage, photosynthetic characteristics were determined by portable photosynthetic determination system （ CIRAS-1, Britain）. The result shows that under drought stress, net photosynthetic rate, transpiration rate, instantaneous water use efficiency, stomatal conductance of the seedlings of Shandongluzhong and Henanbaofeng provenance in potting soil are all high, which indicated that the seedlings of these 2 provenances have stronger characteristics of drought-resistance. But relative indexes of the seedlings of Ningxiapingluo, Beijingmiyun are small.