陕北石油污染对土壤球囊霉素含量的影响

球囊霉素（Glomalin）是丛枝菌根真菌产生的一种糖蛋白，总球囊霉素代表土壤长期积累的糖蛋白总浓度，易提取球囊霉素则反应近期分泌的浓度值。本研究以陕北川口采油厂油井土壤和安塞原油泄漏土壤为研究样地，采集石油污染土壤样品，测定丛枝菌根真菌孢子密度，土壤总球囊霉素、易提取球囊霉素的含量和土壤理化性质，并进一步分析球囊霉素与各类因子的相关性。结果表明，陕北土壤石油污染为点污染，10个样点中有5个点土壤石油烃含量超过500 mg·kg-1达到污染。由泄漏事故造成的原油污染最高达到16 980.0 mg·kg-1，远远超过日常生产带来的危害。川口油井旁样点0~20 cm土层孢子密度为0.48~4.8个·g-1干土，安塞样点0~20 cm土层孢子密度为2.5~10.1个·g-1干土，川口和安塞都是荒地对照点6点的孢子密度显著较高。川口油井旁样点0~20 cm土层总球囊霉素的含量在1.02~2.73 mg·g-1，0~20 cm土层易提取球囊霉素的含量在0.31~0.85 mg·g-1；安塞样点中0~20 cm土层总球囊霉素的含量在1.05~2.77 mg·g-1，0~20 cm土层中易提取球囊霉素的含量在0.14~0.88 mg·g-1，都是显著低于当地无污染对照土样。土壤总球囊霉素和易提取球囊霉素均与AM真菌孢子密度极显著正相关，并与土壤速效氮、土壤脲酶和酸性磷酸酶活性呈显著正相关。易提取球囊霉素与土壤石油烃浓度负相关，说明近期土壤中丛枝菌根真菌的活性和次生代谢受到石油污染的显著抑制。

Effect of petroleum contamination on concentration of glomalin in soil of Northern Shaanxi

Glomalin is a glycoprotein secreted from the hyphae of arbuscular mycorrhizal (AM) fungi that can contribute to formation of soil aggregates. The concentration of glomalin is affected by many kinds of factors. Production process of oil extraction might cause petroleum pollution, as well as oil leakage accident which might lead to huge ecologic disaster. The aim of this paper is to expose the primary impact of petroleum pollution on arbuscular mycorrhizal fungi and its glomalin concentration in soil. The study was carried out in petroleum polluted soil in Northern Shaanxi. The soil samples collected from ten sites were divided into sections corresponding to 0~10 and 10~20 cm soil depth, five sites of which were near the oil wells in Chuankou work area and the others were from contaminated soil caused by oil leakage in Ansai County. The spore density of AM fungi and the concentration of glomalin were measured respectively. The correlation between glomalin concentration and physic-chemical properties of contaminated soil were also analyzed. The results showed that five soil samples were contaminated by petroleum hydrocarbon;the maximal value of petroleum hydrocarbon concentration up to 16 980 mg·kg-1. The spore density of AMF from contaminated soil ranged from 0.48 to 4.8 per gram of dry soil in Chuankou sites and ranged from 2.5 to 10.1 per gram of dry soil in Ansai sites. Spore densities were significantly higher in the clean soil than those in contaminated soil. The Total Glomalin (TG) ranged from 1.02 to 2.77 mg·g-1 in 0~20 cm soil layer, and the Easily Extractable Glomalin (EEG) in 0~20 cm soil layer ranged from 0.14 to 0.88 mg·g-1. Both of them were significantly lower than those in clean soil. Correlation analysis showed that both TG and EEG were positively corrected with spore density,soil available nitrogen,urease activity and acid phosphatase activity. But EEG was negatively related to concentration of total petroleum hydrocarbon, illustrating that arbuscular mycorrhizal fungi have contributed to the nitrogen fertilization in soil, and the concentration of EEG is obviously inhibited by petroleum pollutants.