盐胁迫对7种造林树种生长量及生理特性的影响

Effect of Salt Stress on Growth and Physiological Characteristics of Seedlings of Seven Tree Species

采用温室盆栽试验方法,研究不同盐胁迫水平对香椿、刺槐、楸树、日本柳杉、常绿白蜡、墨西哥落羽杉和北美红栎1 a生苗木的生长及生理生化指标的影响。试验共设4种盐处理水平(CK:0;A:1 g/L;B:2 g/L;C:3 g/L),处理时间为60 d。结果表明,土壤盐胁迫下7树种苗木的生长、生理指标及营养吸收都发生显著变化。7树种的高生长增量和地径生长增量随盐胁迫水平增大而降低,其中常绿白蜡和北美红栎显著下降。盐胁迫也导致叶片质膜透性、MDA含量、相对水分亏缺(RWD)及脯胺酸含量增大,且盐胁迫与质膜透性、MDA含量和RWD之间存在极显著的正相关,但与脯胺酸不具有明显的相关性。7树种的SOD变化与盐胁迫处理没有明显相关性。7树种中叶部Na+、K+含量随盐胁迫的增大普遍增加,但楸树和北美红栎中的K+含量出现低于对照现象。盐胁迫与Na+含量之间存在显著的正相关。坐标综合评定及聚类分析结果表明,刺槐和墨西哥落羽杉抗盐能力较强,香椿、楸树和日本柳杉抗盐能力中等,常绿白蜡和北美红栎抗盐能力较差。

One - year - old seedlings of seven tree species, Toona sinensis ,Robinia pseudoacacia, Catalpa bungei , Cryptomeria japonica, Fraxinus griffithii , Taxodium mucronatum and Quercus rubra , were grown in pots under greenhouse conditions with varying soil salt （NaCl） contents （ CK： 0, A ： 2 g/L, B ： 2 g/L, C ： 3 g/L） to study the effects of salt contents on growth, physiological indexes and uptake of nutrients. The time of treatment was 60 days. The results showed that soil salt contents had significant effects on growth, physiological indexes and uptake of nutrients of the seven tree species. The height and diameter decreased with the increase of soil salt stress, and the growth indexes of Fraxinus griffithii and Taxodiurn mucronatum decreased remarkably. The membrane leakage, MDA content, RWD and praline contents increased with the increase of soil salt stress, and there was significant positive relativity betv,een MDA ccntent, membrane leakage and praline content and soil salt stress, but there was no interrelation between praline content and salt stress. The result indicated that there was no remarkable variation of SOD activity with the increase of salt stress in seven tree species. The total Na^＋, K ^＋ content in leaf increased with the increase of soil salt stress, but K ^＋ content of Catalpa bungei and Quercus rubra reduced in salt stress. Na ^＋ contents had remarkable relativity with salt stress. The result from coordinate integrative and cluster analysis indicated that the seven tree species were classified into three types of salt tolerance. Type 1, including Robinia pseudoacacia and Taxodium mucronatum, were resistant to salt stress. Type 2, including Toona sinensis, Catalpa bungei and Cryptomeria japonica, were moderately tolerant to salt stress. Type 3, including Fraxinus rubra, were intolerant to salt stress.