单 位：
华南农业大学;中国林业科学研究院林业研究所
摘 要：
水是西北造林育种需要考虑的关键环境因子,速生树种高耗水现象是西北造林中亟待解决的问题。为筛选适宜造林的楸树无性系,本研究利用盆栽称重法及Li-6400XT便携式光合作用分析系统(Li-cor,U.S.)对于5个楸树无性系(004-1、015-1、7080、1-3、1-4)进行比较。结果显示:试验地甘肃天水地区午间14:00时气温达全天最高,为41.1±1.86℃,湿度仅为39.21±2.65%。在此条件下,5个楸树无性系耗水量及耗水速率均出现"单峰变化",可归为"非蒸腾午休型"。其中无性系1~3午间耗水速率最大,达到7.9691±0.1367 mmol·m-2·s-1;楸树无性系全天耗水量较高,在1630.42±38.27~2089.95±34.14 g·d-1,平均为1709.30±52.38 g·d-1,但其日间生产能力较高,日间耗水速率占全天耗水速率92.78%,显著高于毛白杨。与其他4个无性系相比,无性系004-1水分利用效率出现"双峰"现象,分别在12:00时及16:00时出现两个峰,全天水分利用效率总和达到15.723±1.231μmol·mmol-1。因此,楸树耗水速率与普通植物相当,耗水量较高的原因与其较大的叶面积有关;无性系004-1较其他4个无性系,具有更高的苗高、地径,且整株叶面积达1.9907±0.032 m2;在水分利用效率、耗水速率上也表现出良好的水分利用能力和生长能力,可作为当地丰产速生林的优质无性系进行种植。
译 名：
Comparison among Characteristics of Water Consumption in 5Clones of Catalpa bungei
作 者：
DONG Lei;LI Ji-yue;XIE Kun;WANG Jun-hui;College of Forestry,South China Agricultural University;Key Laboratory of National Forestry Bureau, Institute of Forestry,Chinese Academy of Forestry;
关键词：
Catalpa bungei clones;;water consumption;;transpiration;;water use efficiency(WUE)
摘 要：
Drought was considered to be a key factor for breeding and forestation in northwest China. High water consumption of fast growing trees was an important problem for forestation. To compare water consumption of Catalpa bungei, water consumption, transpiration rate, water use efficiency(WUE) of 5 Catalpa bungei clones were studied by Li6400 XT Portable Photosynthesis System and SP-30 Precision Balance. Results showed that temperature got a peak point(41.1±1.86℃) whereas humidity was only 39.21±2.65% at 14:00. In such hydro-thermal conditions, mass water consumption and water consumption rate of 5 clones had a single peak in a whole day and to be classified as "non-transpiration break type". Clone 1-3 had a maximum midday water consumption rate at 7.9691±0.1367 mmol·m-2·s-1. The range of mass water consumption of 5 clones was from 1630.42± 38.27 to 2089.95± 34.14 g·d-1, average was 1709.30± 52.38 g·d-1. The average of daytime water consumption and total water consumption rate was 92.78% which indicated Catalpa bungei was a high daytime productive species. Among 5 clones, clone 004-1 got double peak(at 12:00 and 16:00) in daytime water use efficiency and reached 15.723±1.231 μmol·mmol-1 in a day. Conclusion indicated: 1) water consumption rate of Catalpa bungei had no significant difference with other normal trees. Due to the big leaf area, Catalpa bungei had high total water consumption; 2) clones 004-1 which had a greater capability of water use and water consume among 5 clones was considered as a high quality clones cultivated in northwest China.
