干旱胁迫对两种速生树种苗木生理指标的影响

Effects of drought stress on seedlings physiological indexes of two fastgrowing tree species

以竹柳和尾巨桉2种速生树种为试材进行干旱胁迫模拟盆栽试验,通过对比干旱胁迫后叶片中膜脂过氧化及保护酶和渗透调节物质含量的变化,对供选树种进行抗旱性能分析与评价,为在华南地区选育优良的抗旱、节水速生树种提供重要的理论支持和参考依据。试验结果表明,两个树种在干旱胁迫下都表现出MDA、SOD、可溶性蛋白质含量先升高后降低的趋势,尾巨桉较竹柳都先达到峰值。POD活性呈先升高后降低再升高的趋势,尾巨桉的两个峰值都比竹柳出现的早,但竹柳的最大值比尾巨桉高出199.73 mg·g-1min-1。脯氨酸、可溶性糖含量为逐渐增加的趋势,在干旱胁迫24 d(重度干旱)达到最大值。含量表现出先增大后减小的规律,竹柳的峰值比正常水分条件下含量增加了4.60倍,高于尾巨桉的4.44倍。经过对6项指标的综合分析并结合植物的抗旱性表现,得出竹柳比尾巨桉的适应性强,抗旱性能较好。

By taking bamboo willow and Eucalyptus urophylla× Eucalyptusgrandis seedlings as the tested materials, the drought stress experiments were conducted with pot-culture method. Through comparing the changes of membrane lipid peroxidation and protective enzyme and osmoregulation substances in the seedlings after stressed by drought, the of drought-resistance performance of the tested trees were analyzed and evaluated. The results show that after drought stress treatments, the contents of MDA, SOD and soluble protein in the two tree species increased at first and then decreased; the three values of E. urophylla× E. grandis reached the peak values earlier and higher than that of bamboo willow; the POD activity increased at first, then decreased and finally increased, the peaks ofE. urophylla× E. grandis appeared earlier than that of bamboo willow, but the maximum value of bamboo willow was higher by by 199.73 mg·g^-1min^-1 than that ofE. urophylla× E. grandis; their proline and soluble sugar contents gradually increased, peaked in 24th day（severe drought）, showed a law of increase first then decrease, the peak value of bamboo willow increased by 4.60 times than that of the normal moisture conditions; Through the comprehensive analysis of six indicators combined with the drought resistance performance of plants, it was concluded that the bamboo willow has strong adaptability and well drought resistance performance than E. urophylla × E. grandis.