亏缺灌溉对青绿苔草生理与生长的影响

Effect of Deficit Irrigation on Physiology and Growth of Carexleucochlora

青绿苔草为干旱半干旱的北方地区适宜应用的地被植物。采用盆栽法研究亏缺灌溉对青绿苔草生理与生长的影响。采取同时不同量的灌溉处理方法,根据充足灌溉下对照植株消耗的水量(ETc),设定75%ETc、50%ETc、25%ETc3个亏缺灌溉水平,以100%ETc为对照。结果表明,随着亏缺程度的加深与处理时间的延长,土壤水势和土壤含水量显著下降,25%ETc处理下土壤水势和相对含水量分别降低到(-79.5±1.3)kPa、18.3%±1.1%;叶水势由(-1.37±0.11)MPa显著下降到(-2.30±0.16)MPa;气孔导度、净光合速率和蒸腾速率显著下降,水分利用效率显著提高;丙二醛含量显著增加,最高比对照增加269.0%;株高、冠幅、叶片SPAD值、分蘖数、茎叶干重、根干重均显著下降,根冠比升高。即使75%ETc的亏缺灌溉对植株的生理和生长产生了显著影响,说明青绿苔草对水分亏缺比较敏感;但所有处理下植株均生长正常,未表现出受害症状,反映了青绿苔草对干旱具较强的适应性。

Carex leucochlora is a ground cover plant developed recently in arid and semi-arid area of northern China. The effects of deficit irrigation on physiology and growth of C. leucochlora was studied. The irrigation treatments were conducted with different amounts of water at the same time. According to the water consumed by control plants under adequate irrigation （ETo）, three deficit irrigation levels of 75 % ETa, 50% ET and 25% ETc were set, with 100% ETc as the control. The results showed, along with the deficit deepening and the treatments prolonging, the soil water potential and the soil moisture decreased significantly, with the lowest values of （-79.5±1.3） kPa and 18.3G±1.1% under 25% ETc treatment; the leaf water potential decreased significantly from （-1.37±0. 11） MPa to （-2. 30±0. 16） MPa; the malondialdehyde （MDA） content increased significantly and the highest value was 269.0% more than the control; the plant height, the canopy width, the leaf SPAD value, the tiller number, the shoot dry weight and the root dry weight all decreased significantly, and the root/shoot ratio increased. Even the deficit irrigation of 75 % ETc affected the physiology and the growth of the plants significantly,indicated that C. leucochlora is sensitive to water. But the plants grew normally under all the treatments with no damage symptom, indicating stronger adaptation of C. leucochlora to drought.