摘要
通过温室盆栽试验,研究了低钾(0.01mmol·L-1)和正常钾(2.5mmol·L-1)水平对NaCl胁迫下罗布麻(Apocynum venetum)生长和离子吸收分配的影响。结果表明,随着介质中NaCl浓度的增加,罗布麻的根、茎、叶的生物量和株高呈下降趋势;但相同浓度NaCl处理下,低钾和正常钾之间无显著差异(P>0.05)。罗布麻各器官中Na+含量随介质NaCl浓度的增加显著上升(P<0.05),叶中上升幅度明显大于根和茎;叶和茎中K+随介质NaCl浓度的增加显著下降,但仍维持较高水平,根中K+浓度能保持稳定;低钾和正常钾水平下,与无盐胁迫(对照)相比,50mmol·L-1 NaCl处理植株叶中K+浓度无显著变化。在对照条件下,罗布麻体内积累大量K+,其叶中K+浓度是Na+的15倍多。可见,增强K+的选择性吸收和运输,保持叶部较高的K+含量和K+/Na+比是罗布麻适应盐逆境的重要生理机制。
The effects of two K+levels(0.01 and 2.5mmol·L-1)on the growth,ion absorption and distribution of Apocynum venetum under NaCl stress were investigated by the pot experiment.The results indicated that the biomass and plant height of A.venetumdecreased with the increase of external NaCl concentration,however,there was no significant difference between 0.01 and 2.5mmol·L-1 K+under the same salt treatment(P>0.05).Na+contents in all tissues of A.venetumincreased significantly(P<0.05)with the increase of external NaCl concentration and the increase rate in leaf was greater than that in root and stem.In contrast to Na+,K+contents decreased significantly but still maintained at a high level in leaf and stem and maintained stable in root with the increase of external NaCl concentration.Furthermore,compared with the control,K+contents in leaf did not significantly change when A.venetum was exposed to 50mmol·L-1 NaCl.Moreover,A.venetum accumulated high contents of K+in the absence of salt stress,especially in leaf where K+contents were 15 times higher than that of Na+.In conclusion,enhancing the capacity of selective absorption and transport for K+,and hence maintaining high K+contents and K+/Na+ratio in leaf are the key adaptive mechanisms of salt-tolerance in A.venetum.
出处
《草业科学》
CAS
CSCD
北大核心
2014年第11期2088-2094,共7页
Pratacultural Science
基金
教育部博士点基金优先发展领域项目(20130211130001)
兰州大学中央高校基本科研业务费专项资金(lzujbky-2013-203)
