盐与干旱胁迫下格木幼苗生长生理变化

Changes in Growth and Physiology of Erythrophleum fordii Seedlings Under Salt and Drought Stress

以格木幼苗为试验材料,在人工模拟环境条件下,探究了盐(0.1%~0.5%NaCl)与干旱(5%~15%PEG6000)处理下苗木生长生理变化。结果表明:与正常生长条件下的对照相比,供试苗木在盐与干旱处理下受到了明显的胁迫伤害,苗高、地径生长增量均显著降低,其中以0.1%NaCl处理下苗高、地径生长增量的降幅最小,而在10%~15%PEG下苗高、地径生长增量的降幅最大。供试幼苗的叶片相对水分亏缺(RWD)在盐和干旱处理下随着胁迫程度加剧而逐渐增加,但SOD、POD、CAT活性及可溶性糖、可溶性蛋白、游离脯氨酸含量受胁迫影响呈不同变化趋势,在盐胁迫下随着NaCl增加先上升后下降,在干旱胁迫下随着PEG增加而增加。以苗高增量、地径增量、RWD及SOD、POD、CAT活性与可溶性糖、可溶性蛋白、游离脯氨酸含量等7个指标为评价指数,经主成分分析进行耐盐抗旱能力综合分析,表现为0.1%NaCl处理下抗性最强,而10%~15%PEG处理下抗性最弱。研究认为,格木具有一定的耐盐性,但对干旱敏感性较强,今后进行格木人工林培育时建议避开干旱、降雨量较少地区,可在滨海但土壤水分条件状况较佳的地带进行种植。

Using Erythrophleum fordii seedlings as experimental materials,changes in growth and physiology of seedlings under salt(0.1%-0.5%NaCl)and drought(5%-15%PEG6000)treatments were investigated under artificial simulated environmental conditions.The results showed that compared with the control under normal growth conditions,the tested seedlings were subjected to obvious stress and damage under salt and drought treatments,and the growth increments of seedling height and ground diameter were significantly reduced,among which the decrease of height and diameter growth increments under 0.1%NaCl treatment was the smallest,while the decrease of height and diameter growth increments under 10%-15%PEG was the largest.The relative water deficit(RWD)of the leaves of the tested seedlings increased gradually with the increase of stress degree under salt and drought treatments,but the activities of SOD,POD,CAT and the contents of soluble sugar,soluble protein and free proline were affected by stress types,showing different trends,which increased first and then decreased with the increase of NaCl under salt stress,and increased with the increase of PEG under drought stress.The seven indexes of seedling height increment,ground diameter increment,RWD,the activities of SOD,POD and CAT,soluble sugar,soluble protein and free proline content were used as evaluation indexes.The comprehensive analysis of salt tolerance and drought resistance was carried out by principal component analysis.The results showed that the resistance was the strongest under 0.1%NaCl treatment,while the resistance was the weakest under 10%-15%PEG treatment.The study suggests that Erythrophleum fordii has certain salt tolerance,but it is more sensitive to drought.In the future,it is recommended to avoid drought and less rainfall areas when cultivating Erythrophleum fordii plantations,and it can be planted in coastal areas with better soil moisture conditions.