Effect of Seaweed Extract on Droughty Resistance of Sugarcane Seedling

本文研究海藻提取物对甘蔗苗期叶片抗氧化酶活性、株高、生物量及叶片SPAD值的影响，为明确海藻提取物缓解甘蔗苗期干旱胁迫提供依据。采用水培方式以粤糖94-128幼苗为研究对象，在10% PEG6000模拟干旱胁迫条件下分别用浓度为0%、0.5%和1% (V/V)的海藻提取物施用于营养液，处理3天后分别测定甘蔗苗期叶片过氧化物酶(POD)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性以及丙二醛(MDA)含量，处理10天后分别测定株高、生物量鲜重及叶片SPAD值。研究结果表明，在干旱胁迫下施用海藻提取物能提高叶片POD、SOD和CAT等抗氧化酶活性，降低叶片MDA含量，使叶片脱水速率得到显著降低，相对含水量得到显著提高，电导率显著下降，增加甘蔗株高和生物量，显著提高叶片SPAD值(p < 0.05)。因此，海藻提取物有望成为一种新的甘蔗抗旱调节剂。 A hydroponic experiment was conducted to explore the effects of various rates of seaweed extracts (prepared from brown alga) on sugarcane growth and physiological response under stimulated drought stress. Yuetang 94-128 was selected based on seedling growth under drought and were planted in pots containing 10 liter of Hoagland solution. The seedlings were subjected to drought levels using 0% or 10% PEG6000 mixed with Hoagland solution. Three seaweed extract treatments consisting of 0%, 0.5%, and 1% (V/V) of the seaweed extract level in full strength Hoagland solution were applied. The activity of peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT), the content of MDA and electric conductivity (EC) of leaves were measured after 3 days with treatments; the leaf dehydration rate (LDR), the relative water content (RWC), plant height and fresh weight were measured after 10 days with treatments. The results showed that the antioxidant enzymes activity in sugarcane leaves of POD, SOD and CAT were improved, the MDA content, the electric conductivity and the leaf dehydration rate were significantly decreased, while the relative water content, plant height, biomass, leaf SPAD value were greatly increased with the application of seaweed extract under drought stress (p < 0.05), which implied that seaweed extract has a potential for drought-resistant modulation.