不同类型盐分对盐爪爪种子萌发和幼苗生长的影响

Effects of sodium salinity stress types on the germination of Kalidium foliatum seeds and its young seedling growth

采用培养皿法研究不同类型钠盐胁迫对荒漠植物盐爪爪种子萌发率、萌发指数、幼苗芽长和根长,分析盐爪爪种子萌发与幼苗生长适应不同类型盐碱地的机制,为种植盐爪爪生态修复不同类型盐碱地提供了科学依据。结果表明:(1)NaCl、Na_(2)SO_(4)、NaHCO_(3)、Na_(2)CO_(3)均显著抑制盐爪爪种子的萌发率和萌发指数。(2)回归方程分析盐爪爪萌发期的耐NaCl、Na_(2)SO_(4)、NaHCO_(3)、Na_(2)CO_(3)临界值分别为325 mmol·L^(-1)、267 mmol·L^(-1)、245 mmol·L^(-1)和166 mmol·L^(-1),其极限值分别是671 mmol·L^(-1)、580 mmol·L^(-1)、569 mmol·L^(-1)和389 mmol·L^(-1),相对于中性盐,盐爪爪种子萌发时对碱性盐更敏感。(3)NaCl、Na_(2)SO_(4)、NaHCO_(3)、Na_(2)CO_(3)均显著抑制盐爪爪幼苗芽和根的生长,盐爪爪种子萌发和幼苗生长对这4种钠盐的响应差异显著;相对于幼苗芽,幼苗根的响应更为敏感,可将根长作为评价盐爪爪耐盐性的参数,碱性盐毒害强于中性盐;根据盐分对盐爪爪种子萌发和幼苗生长的毒害性顺序依次为:NaCl<Na_(2)SO_(4)<NaHCO_(3)<Na_(2)CO_(3)。

The effects of different types of sodium salt stress on seed germination and seedling growth in the eremophyte Kalidium foliatum were studied by measuring the germination rate,germination index,bud length,and root length.In addition,the mechanism of seed germination and seedling growth when adapting to different types of saline alkali land was explored;this work provides insights into the development desert restoration and forage industry in arid areas through K.foliatum planting.Results showed that NaCl,Na_(2)SO_(4),NaHCO_(3),and Na_(2)CO_(3) significantly inhibited the germination rate and germination index of K.foliatum.According to regression analysis,the critical values of NaCl,Na_(2)SO_(4),NaHCO_(3),and Na_(2)CO_(3) were 325,267,245,and 166 mmol·L^(-1),respectively,whereas the limit values were 671,580,569,and 389 mmol·L^(-1),respectively.In addition,NaCl,Na_(2)SO_(4),NaHCO_(3),and Na_(2)CO_(3) significantly inhibited the growth of K.foliatum shoots and roots.However,seed germination and seedling growth responses differed significantly according to the four sodium salt exposures.For example,the toxicity of alkaline salt was greater than that of neutral salt.In young seedlings,the shoots were more sensitive to salt exposure than were the roots.Furthermore,root length could be used as a parameter to evaluate the salt tolerance of K.foliatum.Finally,according to the degree of salt toxicity on seed germination and seedling growth,the toxicity to K.foliatum can be ranked as follows:NaCl<Na_(2)SO_(4)<NaHCO_(3)<Na_(2)CO_(3).