傅家边丘陵山地滨梅根围AM真菌与土壤酶活性的关系

为揭示AM真菌对宿主滨梅（Prunus maritima）的作用特点及对根部土壤酶活性的影响,于2009年4月、7月和10月分别从江苏傅家边丘陵山地滨梅根围分0～10、10～20、20～30、30～40、40～50 cm 5个土层采集土壤样品,观察滨梅AM菌根结构,测定了AM真菌侵染率、孢子密度、土壤磷酸酶、脲酶活性及有效磷、碱解氮含量,着重分析了AM真菌与土壤酶活性之间的关系。结果表明,滨梅能与AM真菌形成良好的共生关系,共生体为泡囊-丛枝结构;AM真菌侵染率和孢子密度分别在7月份和10月份最高,均出现在0～20 cm土层,并随土层加深而下降;AM真菌侵染率与土壤酸性磷酸酶、中性磷酸酶、碱磷酸酶活性显著正相关,而与脲酶活性无相关性;AM真菌孢子密度与碱性磷酸酶、脲酶活性呈极显著正相关关系;孢子密度与土壤有效磷、土壤碱解氮含量显著正相关,但AM真菌侵染率仅与土壤有效磷含量显著正相关;孢子密度与菌根侵染率之间无相关性。可见,滨梅AM真菌侵染率与孢子密度有明显的时空分布并与土壤因子尤其是某些土壤酶活性密切相关,且AM菌根的形成是滨梅适应丘陵山地干旱贫瘠环境的有效对策之一。

Relationship between Arbuscular Mycorrhizal Fungi and Soil Enzyme Activities of Beach Plum in Fujiabian Hilly Area

To reveal the functions of arbuscular mycorrhizal （AM） fungi to beach plum and soil enzyme activities, we collected five samples with the rhizosphere of beach plum for each soil layer （0-10 cm, 10-20 cm, 20-30 cm, 30-40 cm and 40-50 cm） from the Fujiabian hilly area in April, July and October 2009, respectively. We observed the AM mycorrhizal structure, determined the AM fungi infection rate, spore density, activities of phosphatase and urease, and the contents of available P and N in the soil, and analysed the relationship between AM fungi and soil enzymes. Results showed that AM fungi established a good symbiotic relationship with beach plum roots, and the symbioses were of vesicle-arbuscular structure. The 0-20 cm soil layer had the highest rate of AM infection and spore density in July and October, respectively, which decreased with the increase in soil depth. The AM fungi infection rate showed significant positive correlation with the activities of acid phospha- tase, neutral phosphatase and alkaline phosphatase, but no correlation with urease in soil. The AM fungi spore density demonstrated significant positive correlation with alkaline phospha- tase and urease in soil. There was a significant positive correlation between spore density and available P （or N）, but no correlation between AM fungi infection rate and available N. Spore density showed no correlation with AM fungi infection rate. The AM fungi infection rate andspore density had obvious spatial and temporal distribution, and were related closely to the activity of soil enzymes. With AM mycorrhiza, beach plum could grow well on poor hilly mountains.