【摘要】 以刺槐品种‘多彩青山’（抗盐强品种）和‘紫艳青山’（抗盐弱品种）为试材,采用盆栽试验法,设盐胁迫和空白对照两个处理,研究了两个刺槐品种根系离子吸收、根际土壤酶和微生物种群数量的变化。结果如下:（1）盐胁迫处理的‘多彩青山’和‘紫艳青山’根系中的Na⁺、K⁺、Ca²⁺、Mg²⁺含量均发生不同程度变化,其中Na⁺含量在盐胁迫初期先缓慢增加,后随处理时间延长迅速增加;K⁺、Ca²⁺、Mg²⁺含量呈现缓慢降低趋势;‘多彩青山’根系4种离子含量波动幅度比‘紫艳青山’小。（2）盐胁迫显著降低了刺槐根际土壤酶的活性,胁迫第28 d时,‘多彩青山’的根际土壤脲酶、蔗糖酶、中性磷酸酶、过氧化氢酶活性分别比胁迫0 d降低44.97%、60.87%、36.96%、23.80%,‘紫艳青山’分别比胁迫0 d降低52.45%、74.48%、42.52%、36.67%。（3）盐胁迫下刺槐的根际土壤细菌、真菌、放线菌的数量均明显下降,胁迫第28 d时,‘多彩青山’根际的细菌、真菌、放线菌数量分别比胁迫0 d减少39.04%、49.45%、44.20%,‘紫艳青山’分别比胁迫0 d减少53.41%、57.05%、47.53%。（4）盐胁迫下根系Na⁺含量与根际土壤酶活性、根际土壤微生物种群数量之间有显著负相关性;根系K⁺含量与根际土壤脲酶、过氧化氢酶活性以及细菌数量之间有显著正相关性。综合来看,盐胁迫下植物根系离子的平衡被打破,根际土壤酶和微生物种群数量受到抑制;刺槐品种抗盐性强弱与根系离子平衡、根际土壤酶、微生物的活性维持有关,抗盐性强的品种‘多彩青山’比抗盐性弱的品种‘紫艳青山’的根系离子平衡受破坏较小,根际土壤酶和微生物的活性受抑制程度较低。更多还原

【Abstract】 Using the black locust cultivars Duocai Qingshan with high salt tolerance and Ziyan Qingshan with weak salt tolerance as materials,a pot experiment was conducted to study the changes of the root ion adsorption and the enzyme and microbial populations in rhizosphere soil of black locust under two treatments of salt stress and black control. The results were as follows:（ 1） under salt stress,the contents of Na⁺,K⁺,Ca²⁺ and Mg²⁺in the roots of Duocai Qingshan and Ziyan Qingshan changed in different degrees. Among them,the Na⁺ content increased slowly at the early stage and then increased rapidly with the extension of salt stress; the K⁺ content increased firstly companied with Na⁺,and then decreased gradually; the contents of Ca²⁺and Mg²⁺displayed the trends of decreasing slowly. The fluctuation amplitude of the 4 ion contents of Duocai Qingshan were smaller than that of Ziyan Qingshan.（ 2） The activities of urease,invertase,neutral phosphatase and catalase in the black locust rhizosphere soil decreased significantly under the salt stress treatment. After stressed for 28 days,the soil enzyme activities of urease,invertase,neutral phosphatase and catalase in Duocai Qingshan decreased by 44. 97%,60. 87%,36. 96% and 23. 80% respectively,while those in Ziyan Qingshan decreased by 52. 45%,74. 48%,42. 52% and 36. 67% respectively.（ 3） Under the salt stress treatment,the numbers of rhizosphere bacteria,fungi and actinomycetes significantly decreased in black locust,and those of Duocai Qingshan decreased by 39. 04%,49. 45% and 44. 19% respectively,while those of Ziyan Qingshan decreased by 53. 41%,57. 05% and 47. 53% respectively.（ 4） There were significantly negative correlations between the Na⁺ content and the rhizosphere soil enzyme activities and microbial populations; there were significantly positive correlations between the K⁺ content and the rhizosphere soil urease and catalase activities and bacteria number. In conclusion,the ion balance in roots of black locust was broken,and the enzyme activities and microbial populations in rhizosphere soil were inhibited under salt stress. The salt tolerance of black locust cultivars were related to the ion balance in roots,the maintaining of rhizosphere soil enzyme activities and microbial populations. The suppression degree of Duocai Qingshan with high salt tolerance were lower than that of Ziyan Qingshan with weak salt tolerance.更多还原