| 摘要: |
| [目的]阐明荒漠地区AM真菌生态作用及其与沙生植物的互作关系,为AM真菌资源的合理利用及荒漠环境的恢复提供理论依据.[方法]在毛乌素沙地东北缘的中国科学院植物研究所鄂尔多斯沙地草地生态站设立样地,于2007年4,8和10月,采集油蒿(Artemisia ordosica)根围0～10,10～20,20～30,30～40和40～50 cm土层土样,分离其丛枝菌根(Arbuscular mycorrhiza,AM)真菌并测定相关土壤因子,系统研究油蒿根围AM真菌的时空分布.[结果]AM真菌在油蒿根系的总定殖率(86.9%)和丛枝定殖率(24.8%)均较高,说明二者间有良好的共生性;油蒿根围AM真菌孢子密度和定殖率随季节和土壤深度的变化而具有明显的时空性差异,并与土壤微环境显著相关.油蒿根围0～40 cm土层的菌丝定殖率和泡囊定殖率均较高且无显著变化,丛枝定殖率以30～40 cm土层较大.AM真菌孢子密度、土壤养分及土壤酶活性最大值均出现在0～20 cm土层,并随土壤深度增加而递减.AM真菌孢子密度、土壤速效磷含量、速效氮含量及土壤酶活性均随时间积累而增加,于10月份达到最大值.AM真菌孢子密度与土壤速效磷含量及磷酸酶活性呈显著正相关,丛枝定殖率与有机质含量、速效氮含量及土壤脲酶、酸性磷酸酶、碱性磷酸酶的活性均呈显著负相关,仅与pH显著正相关.[结论]AM真菌对提高寄主植物抵御外界干扰的能力维护荒漠土壤生态系统结构的完整性和功能稳定性具有重要意义. |
| 关键词: 油蒿 毛乌素沙地 AM真菌 时空分布 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金 |
|
| Studies on spatio-temporal distribution of AMF in the rhizosphere of Artemisia ordosica in Mu Us desert |
|
|
| Abstract: |
| 【Objective】 The study elucidated the ecological function of AM fungi and interaction between sand fixation plants and AM fungi so as to provide more information for the utilization of AM fungi and for the environmental restoration in desert regions.【Method】 The study was carried out at Ordos Sandland Ecological Station of Institute of Botany,the Chinese Academy of Sciences,located in the northeast of Mu Su desert. The soil samples were collected from a depth of 50 cm into 5 sections,i.e.0-10,10-20,20-30,30-40 and 40-50 cm in the rhizosphere of Artemisia ordosica in 2007.The spatio tempora distribution and colonization of AM fungi were measured in the rhizosphere of A. ordosica.【Result】 AM fungi had a relatively high total colonization and arbuscular colonization on the roots of A.ordosica.The colonization of hyphae and vesicles were not significantly different in 0-40 cm soil layer.The highest arbuscular colonization existed at the 30-40 cm soil layer.The maximal value of the spore density occurred at 0-20 cm soil layer,and then decreased with soil depth,the soil factors and soil enzyme activities showed the same trend as well.Spore density,soil factors and soil enzyme activities had an increasing change with sampling time,and the highest values of them appeared in October.Spore density was significantly and positively correlated with available P and with phosphatase.Arbuscular colonization was negatively correlated with organic matter contents,available N and three soil enzyme activities,but positively correlated with pH. 【Conclusion】A.ordosic could establish good symbiosis with AM fungi,which was the main reason for maintaining integrity and stability of the desert ecosystem. |
| Key words: Artemisia ordosica Mu Us desert AM fungi Spatio-temporal distribution |
