荒漠环境柠条锦鸡儿AM真菌空间分布

为充分利用AM真菌资源,对陕西省榆林市沙生植物园、鄂尔多斯生态研究站和宁夏回族自治区沙坡头3个不同生态条件下柠条锦鸡儿(Caragana korshinskii)AM真菌空间分布进行了研究。结果表明,柠条锦鸡儿菌根类型为I-型(Intermediate type),泡囊形态多样,形成于细胞间或细胞内,丛枝结构包括树枝状和花椰菜状2种类型。在形成丛枝菌根的同时,柠条锦鸡儿根部也能普遍被暗色有隔内生真菌感染。AM真菌定殖率和孢子密度与样地生态条件密切相关。最大孢子密度发生在0～10 cm土层,并随土层加深呈下降趋势,孢子密度与土壤速效N、有机质、脲酶和蛋白酶呈极显著正相关,泡囊定殖率与速效P含量呈显著正相关,丛枝定殖率与土壤pH呈显著正相关。孢子密度、泡囊和丛枝定殖率可作为检测土壤环境状况的指标。

Spatial distribution of arbuscular mycorrhizal fungi of Caragana korshinskii in desert environment

The arbuscular mycorrhizal type and AM fungal ecological distribution of Caragana kor- shinskii in three representative sites of Shaanxi Yulin Rare Sandy-plants conversation field,the Or- dos sandy land ecological station and Ningxia Shapotou were studied.The results showed that my- corrhiza type was intermediate type and vesicluar in intercellular and intraeellular with morphologi- cal variety.The structure of arbuscular included tree and cauliflower-shaped.The roots of C.kor- shinskii were also infected with dark septate endophytic fungi.Different sample sites had signifi- cantly affected spore density and the percentage of colonization of vesicle and arbuscule of AM fungi. The spore density at 0-10 cm depth was maximal and decreased with soil depth.There existed sig- nificant positive correlation with soil available N,organic matter,urease and proteinase.There ex- isted significant positive correlation between vesicular colonization and soil P.There existed signifi- cant positive correlation between arbuscular colonization and soil pH.The results suggested that spore density,vesicular and arbuscular colonization were useful indictors for microcosmic monitoring and evaluating soil environment.