钠盐胁迫对藜科一年生草本植物生长和生物量分配的影响

Effects of sodium salt stress on the growth and biomass allocation of Chenopodiaceae annuals

选取河西走廊荒漠绿洲过渡带典型藜科一年生草本植物雾冰藜、刺沙蓬和白茎盐生草为研究对象,分析不同浓度盐分(NaCl和NaHCO_(3),0、50、100、150、200 mmol/L)对3种藜科植物生长、繁殖和生物量分配的影响。研究结果表明:(1)钠盐胁迫下,3种藜科植物的存活率随盐浓度的增加呈下降趋势,雾冰藜和刺沙蓬在200 mmol/L NaCl和200 mmol/L NaHCO3胁迫下无法存活或存活率极低,白茎盐生草在200 mmol/L NaHCO3胁迫下无法存活;(2)钠盐胁迫显著抑制了刺沙蓬的生长和生物量积累,而一定浓度的盐分(50、100 mmol/L)可以促进雾冰藜和白茎盐生草的生长,较高浓度的盐分则抑制其生长;(3)3种植物的根冠比在钠盐胁迫下呈下降趋势,地上部生物量分配随盐浓度增加呈上升趋势,其中低盐胁迫下(50、100 mmol/L)繁殖分配比例增加明显,中高度盐胁迫下(150、200 mmol/L)茎、叶生物量分配比例增加显著,但根系生物量分配随盐分浓度增加而下降,这说明盐分胁迫下增加生物量在地上部的分配是藜科一年生草本植物应对盐胁迫的方式之一;(4)NaHCO3的胁迫作用大于NaCl,3种植物中,白茎盐生草的耐盐性最强,而雾冰藜和刺沙蓬的耐盐能力较差。

Selecting three typical Chenopodiaceae annuals(Bassia dasyphylla,Salsola ruthenica and Halogeton arachnoideus)as study subjects in a typical desert-oasis ecotone in the Hexi Corridor,we investigated the effects of different concentrations of salts(NaCl and NaHCO3,0,50,100,150 and 200 mmol/L)on the growth,reproduction and biomass allocation of three Chenopodiaceae annuals.The results showed that(1)Survival rates of three Chenopodiaceae annuals decreased with the increase of salt concentration under sodium salt stress.Bassia dasyphylla and Salsola ruthenica could not survive or had very low survival rate under 200 mmol/L NaCl and 200 mmol/L NaHCO3 stress,and Halogeton arachnoideus could not survive under 200 mmol/L NaHCO3 stress.(2)Sodium salt stress significantly affected the growth and biomass accumulation of Salsola ruthenica,but certain salt concentration(50 and 100 mmol/L)could promote the development of Bassia dasyphylla and Halogeton arachnoideus,while higher salt concentration could inhibit their growth.(3)The root shoot ratio of the three plants decreased with the increase of salt concentration.The aboveground biomass allocation showed an upward trend with the increase of salt concentration.Among them,the reproductive distribution increased under low-salt stress(50 and 100 mmol/L),and the biomass allocation of stems and leaves increased under medium and high salt stress(150 and 200 mmol/L),while the roots biomass distribution decreased with the increase of salt concentration.It showed that increasing biomass allocation in the aboveground under salt stress is one of the ways of Chenopodiaceae annuals responded to salt stress.(4)The stress effect of NaHCO3 was stronger than NaCl.The saline tolerance capacity of Halogeton arachnoideus was the highest among the three plants,and the capacity of Bassia dasyphylla and Salsola ruthenica was poor.