摘要
通过室内水培试验,研究不同生活型植物对干旱区碱性环境的适应性以及对碱胁迫的适应程度。结果表明:随着培养溶液pH的增大,植物体地上部分和地下部分的生长受到不同程度影响,除骆驼蓬鲜重呈先增加后降低趋势外,刺沙蓬和梭梭的鲜重均表现为逐渐降低趋势,从根冠比的结果可以看出,碱胁迫对地上部分的影响大于对根系的影响;根系活力随着pH的增大,其变化也不尽相同,刺沙蓬和骆驼蓬随着pH的增大,其根系活力呈先增大后减小的趋势,而梭梭的根系活力则随着pH的增大呈增大趋势,这说明一定程度的碱胁迫能促进干旱区植物的生长,一旦超过植物对碱的耐受极限时,植物根系就会受到损伤,根系活力降低;梭梭的耐碱能力较其他两种草本植物强。表明碱胁迫对3种生活型植物的生长均有一定影响,同时在一定程度上也形成了对碱胁迫的适应机制。
A hydroponics experiment of three desert life-form plant species was conducted to investigate the effects of different pH values on the morphological features and activity of roots. The purpose of the experiment was to explore the adaptability of the desert plant species to alkaline soil and saline stress. The results show that the biomasses of roots and aboveground parts of both Salsola ruthenica and Haloxylon ammodendron Bge. were decreased obviously with increasing pH value,but those of Peganum harmala Linn were increased at first and then decreased,and the growth of aboveground parts was more sensitive to alkaline stress than that of roots. The root activity with the increase of pH value was different,that of both S. ruthenica and P. harmala was increased at first and then decreased,but that of H. ammodendron was increased all along. These reveal that the alkaline stress can promote the growth of plants in arid area to a certain extent,but the roots will be damaged and their activity will be decreased when the alkalinity of soil exceeds the tolerance limit of plants. Moreover,the alkalinity tolerance of H. ammodendron is higher than that of other two. In a word,alkaline stress affects negatively on the growth of desert plants to a certain extent,however,a certain adaptability of these plants to alkaline stress has formed.
出处
《干旱区研究》
CSCD
北大核心
2010年第6期915-920,共6页
Arid Zone Research
基金
中国科学院"西部之光"人才培养项目
西部之光项目(XBBS200808)
