摘要
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(中性盐NaCl和碱性盐NaHCO3,0、50、100、150、200 mmol·L^(-1))对3种植物种子萌发、幼苗生长和生理特性的影响。研究结果表明:1)钠盐胁迫下,3种植物的种子萌发和幼苗生长均受到显著抑制。萌发期,种子发芽率、发芽势和发芽指数均随盐浓度增加而下降,但盐胁迫解除后,3种植物种子均可恢复萌发;幼苗生长期,植株株高、主根长和鲜重都随盐浓度增加而下降。2)3种植物生理变化显著,叶绿素含量在钠盐胁迫下呈下降趋势,而丙二醛含量呈上升趋势,游离脯氨酸和可溶性糖含量则呈先升后降趋势,其中,叶绿素含量变化是影响幼苗生长的重要因素。3)轻度(50 mmol·L^(-1))和中度(100、150 mmol·L^(-1))盐胁迫下,3种植物主要通过渗透调节来适应盐胁迫,可溶性糖和游离脯氨酸含量大幅提高,以通过细胞渗透调节提高植物持水能力,维持植物正常生长;而在重度(200mmol·L^(-1))盐胁迫下,丙二醛含量迅速增加,叶绿素分解加速,渗透调节作用减弱,对植物生长的抑制作用明显。4)在个体适应策略上,3种植物通过减少根系物质分配来适应盐分胁迫,在重度盐胁迫下根冠比明显降低。5)碱性盐NaHCO3对3种植物的胁迫效应更大,同时,不同物种不同时期的耐盐性均存在显著差异,其中,白茎盐生草的耐盐性最强,雾冰藜次之,刺沙蓬最弱。
In this study,we selected three typical Chenopodiaceae annuals(Bassia dasyphylla,Salsola ruthenica,and Halogeton arachnoideus)that grow in a typical desert-oasis ecotone in the Hexi Corridor and determined their responses to salt stress.We investigated the effects of different concentrations of salts(NaCl and NaHCO3,0,50,100,150 and 200 mmol·L^(-1))on their seed germination,seedling growth,and physiological characteristics.The results showed that:1)Sodium salt stress significantly inhibited the seed germination and seedling growth of all three species.At the seed germination stage,the germination rate,germination power,and germination index decreased with increasing salt concentrations,but the seeds of all three species were able to recover germination after the removal of salt stress.At the seedling growth stage,the plant height,main root length,and fresh weight decreased with increasing salt concentrations.2)The salts clearly affected the physiological characteristics of the three Chenopodiaceae annuals.As the concentration of the salts increased,the chlorophyll content of three plants showed a downward trend,while the malonaldehyde content showed an upward trend,and the free proline and soluble sugar contents initially increased and then decreased.Among these parameters,chlorophyll content was particularly important for seedling growth.3)Under mild(50 mmol·L^(-1))and moderate(100,150 mmol·L^(-1))salt stress conditions,the three plants adapted mainly through osmotic adjustment,and the contents of soluble sugars and free proline increased significantly to improve the water holding capacity and maintain normal plant growth through cell osmotic regulation.Under severe salt stress(200 mmol·L^(-1)),the malonaldehyde content increased rapidly,chlorophyll decomposed more rapidly,osmotic adjustment was weakened,and there was a clear inhibitory effect of salts on plant growth.4)In terms of individual adaptation strategies to severe salt stress,the three Chenopodiaceae annuals adapted to salt stress by reducing the distribution of resources to the roots and significantly decreasing the root∶shoot ratio.5)Compared with NaCl,the alkaline salt NaHCO3had stronger negative effects on the three Chenopodiaceae annuals.In addition,there were significant differences in the salt tolerance of different species among different growth stages.The species were ranked,from most to least salt tolerant,as follows:H.arachnoideus>B.dasyphylla>S.ruthenica.
作者
郭文婷
王国华
缑倩倩
GUO Wen-ting;WANG Guo-hua;GOU Qian-qian(College of Geographical Sciences,Shanxi Normal University,Taiyuan 030000,China;Key Laboratory of Desert and Desertification,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Science,Lanzhou 730010,China;Linze Inland River Basin Research Station,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730010,China)
出处
《草业学报》
CSCD
北大核心
2023年第3期128-141,共14页
Acta Prataculturae Sinica
基金
国家自然科学基金面上项目(42171033),国家自然科学基金项目(41807518)
中国科学院沙漠与沙漠化重点实验室开放基金(KLDD-2020-05)
山西省面上青年基金项目(201801D221336)资助。
关键词
碱性盐
中性盐
藜科一年生草本
渗透调节
生长权衡
生长阶段
alkaline salt
neutral salt
Chenopodiaceae annuals
osmotic adjustment
growth tradeoff
growth stages