生态学杂志2011，Vol.30Issue(2)：255-261,7.
不同形态氮素配比对盐胁迫下菊芋幼苗生理的影响
Effects of different ratios of mineral nitrogen form on Helianthus tuberosus seedlings physiology under salt stress
摘要
Abstract
A sand cultural experiment was conducted to study the photosynthetic characteristics and ion absorption of Helianthus tuberosus seedlings under the coupling effects of nitrogen nutrition (NH4+-N/NO3--N ratio 4/1, 1/1, and 1/4) and salt stress. Low concentration salt stress had less effect in inhibiting H. tuberosus growth, while high concentration salt stress inhibited the growth remarkably. Under the same salt concentrations, increasing proportion of NO3--N could mitigate the inhibition effect of salt stress, and increase the fresh and dry weights of H. tuberosus. With the increase of salt concentration, the Na+ concentration in seedling' s shoots and roots increased significantly, while the K+ and Ca2+ concentrations decreased. Increasing the proportion of NO3--N promoted the selective absorption of K+ and Ca2+ and their translocation from roots to shoots, making shoots keep high ratios of K+/Na+ and Ca2+/Na+. Under the three ratios of NH4+-N/NO3--N and with increasing salt concentration, the leaf chlorophyll content, photosynthetic rate, transpiration rate, stomatal conductance, and water use efficiency all decreased significantly, while the intercellular CO2 concentration had a significant increase. With the increase of the proportion of NO3 --N and under the same salt concentrations, the chlorophyll content, photosynthetic rate, transpiration rate, stomatal conductance, and water use efficiency increased significantly, while the intercellular CO2 concentration decreased significantly. Nitrogen nutrition at NH4+-N/NO3--N ratio of 1/4 had the best alleviation effect to salt stress, e. g. , under 100 mmol · L-1 NaCl stress, the chlorophyll content, photosynthetic rate, transpiration rate, stomatal conductance, and water use efficiency at NH4+-N/NO3--N ratio of 1/4 increased by 1.63, 1.57,1.39, 1.37, and 1.2 times, respectively, while the intercellular carbon dioxide concentration decreased by 17％, compared with those at the NH4+-N/NO3--N ratio of 4/1. Therefore, relatire to NH4+-N, the increase of the proportion of NO3--N was more conducive to maintain the balance of mineral nutrients, promote the photosynthesis, and enhance the resistance of H. tuberosus to salt stress.关键词
氮素营养/盐胁迫/菊芋/光合作用/离子吸收分类
生物科学引用本文复制引用
王磊,隆小华,孟宪法,刘兆普,罗以筛..不同形态氮素配比对盐胁迫下菊芋幼苗生理的影响[J].生态学杂志,2011,30(2):255-261,7.基金项目
国家科技支撑项目(2008BAD95B05、2009BADA3B04-8和2009BADA8B01)、公益性行业(农业)科研专项项目(200903001-05)资助. （2008BAD95B05、2009BADA3B04-8和2009BADA8B01）
