五唇兰对PEG模拟的干旱胁迫响应研究

Response to Drought Stress Simulated by PEG of Phalaenopsis pulcherrima

摘要:

为了解干旱对五唇兰（Phalaenopsis pulcherrima）生长的影响，以聚乙二醇（PEG）溶液模拟干旱胁迫，对其叶片的光合色素、渗透调节物质和非结构碳水化合物（NSC）含量变化进行研究。结果表明，随着PEG浓度增加，五唇兰植株含水量和鲜质量逐渐下降，以PEG为13.75%~14.84%时最显著。PEG处理显著降低叶片的叶绿素a和b含量。随着植株含水量的降低，叶片可溶性蛋白、淀粉（St）含量均呈下降趋势，可溶性糖（SS）含量、NSC和SS/St均呈先升后降的趋势。因此，干旱胁迫会影响五唇兰植株的含水量和光合产物的积累；在较低程度干旱胁迫下，可溶性糖在抗旱响应中发挥主要作用；随着干旱胁迫程度加深，五唇兰的生理代谢受到严重影响。

Abstract:

In order to understand the effect of drought stress on the growth of Phalaenopsis pulcherrima, the changes in contents of photosynthetic pigments, osmotic adjustment substances and non-structural carbohydrates in leaves were studied. The polyethylene glycol 6000 (PEG) solution was used to simulate drought stress. The results showed that plant water content and fresh weight decreased gradually with increment of PEG concentration, and plant water content and fresh weight decreased significantly treated with PEG from 13.75% to 14.84%. The contents of chlorophyll a and b decreased significantly in leaves treated with PEG. With the decreasing of plant water content, the contents of soluble protein and starch (St) decreased gradually, while the soluble sugar (SS), NSC (non-structural carbohydrate), and SS/St in leaves increased at first and then decreased. Therefore, the drought stress simulated by PEG could significantly affect plant water content and accumulation of photosynthetic products in leaves. Under light drought stress, soluble sugar played an important role in resistance to drought, while the physiological metabolism of P. pulcherrima would be seriously influenced under severe drought stress.