首页 > 分享 > 盐胁迫下氮素形态对海滨木槿幼苗生长及生理特性的影响

盐胁迫下氮素形态对海滨木槿幼苗生长及生理特性的影响

花匠小妙招
2024-12-15 07:12

摘要：

【目的】通过研究盐胁迫下氮素形态对海滨木槿(Hibiscus hamabo)生长特性和生理指标的影响,探讨不同氮素形态营养供应下海滨木槿耐盐性差异及其机理,为提升盐碱地海滨木槿绿化应用技术提供依据。【方法】采集滨海盐土,设置对照、低、中和高4个盐胁迫处理水平,利用盆栽试验方法研究了不同氮素形态[铵态氮( NH+4-N)、硝态氮( NO-3-N)]和盐分胁迫耦合作用下海滨木槿幼苗的生长特性、光合作用、氮和钾离子(K+)含量变化。【结果】经过90 d的胁迫处理,在高盐处理下海滨木槿全部死亡,中盐处理显著降低了其株高、地径,以及茎、叶和总生物量,而低盐处理对其生长没有显著影响。两种形态氮素均有助于提高海滨木槿生长、净光合速率和氮素含量,其中施 NH+4-N在对照土壤中有助于提高植物生物量,但降低了K+含量。在低盐和中盐胁迫处理下,施 NO-3-N显著增加了植物根系和总生物量以及K+含量。【结论】盐胁迫条件下,增施两种形态氮肥均有利于海滨木槿生物量的增加,且能够在一定程度上提高海滨木槿的耐盐性,不同的是 NO-3-N能够有效促进根系的生长, NH+4-N则对地上部分的生长作用明显。在同一盐浓度水平处理下,与 NH+4-N相比, NO-3-N更有利于缓解盐胁迫对海滨木槿的抑制作用。总体来说,盐胁迫下施 NO-3-N有利于维持海滨木槿体内养分及离子含量平衡并改善光合功能,从而增强海滨木槿耐盐性。

关键词: 海滨木槿, 盐胁迫, 氮素形态, 光合, 离子

Abstract:

【Objective】To study the effects of nitrogen (N) form on growth and physiological parameters of Hibiscus hamabo under different levels of salt stress, the salt tolerance and underlying mechanism of H. hamabo under two N forms were discussed. This provides basis for improving application technology of H. hamabo greening in salt-alkaline land. 【Method】A glasshouse experiment was conducted to study the growth characteristics, photosynthesis, N and K+ content of H. hamabo under the combined effects of N forms ( NH+4-N, NO-3-N), and salt stress. Coastal soils were collected at four salt stress levels: control, low, medium and high.【Result】After 90 days of the stress treatment, all the plants died under the high salt treatments. In the medium salt treatments, plant height, ground diameter, stem biomass, leaf and the whole plant were significantly reduced. However, no significant effects on growth were observed following the low salt treatments. Both NH+4-N and NO-3-N increased the growth, net photosynthetic rates and N content of H. hamabo, among which NH+4-N increased the biomass in the control treatments, but decreased K+ content. Under the low and medium salt stress, NO-3-N application significantly increased the biomass of roots and whole plant and K+ content.【Conclusion】Under salt stress, two N forms were both beneficial to H. hamabo biomass, and could improve its salt tolerance to a certain extent. The difference was that NO-3-N could effectively promote the growth of roots, while NH+4-N had a significant effect on the growth of above-ground plant parts. Compared with NH+4-N at the same level of salt stress, NO-3-N was more beneficial to alleviate the inhibition of salt stress on H. hamabo. Therefore, the application of NO-3-N under salt stress is able to maintain the balance of nutrient and ion content, improving the photosynthetic function, and eventually enhancing the salinity tolerance of H. hamabo.

Key words: Hibiscus hamabo, salt stress, nitrogen form, photosynthesis, ion

中图分类号:

S718

Q945.3