我国北方VA菌根真菌某些属和种的生态分布

虽然VA真菌遍布全球,但其属和种的分布是不均衡的,常有程度不同的地域性。以新疆、北京和吉林三地为代表的我国北方土壤中的VA真菌大都为球囊霉属Glomns。对摩西球囊霉G.mosseae、地表球囊霉G.versilorme及未发表种Glomus sp.9等菌种和某些生态因子的统计分析表明:土壤pH、土壤有机质含量和采集地海拔高度对三菌种的分布影响显著。在pH5—9.5范围内,球囊霉属所占比例随土壤pH增高而加大;无梗囊霉属Acaulospora所占比例则随土壤pH降低而加大。pH大于9的土壤中完全没有盾巨囊霉属Scutellospora。虽然球囊霉属主要分布在有机质含量低的土壤中,但其未发表种Glomus sp.9却较多发现于有机质丰富处。无梗囊霉属的某些种对土壤有机质含量在一定选择性。盾巨囊霉属多见于有机质含量为5—10％的土壤中。海拔3000米以上土壤中球囊霉属和无梗囊霉属显著减少,盾巨囊霉属则已绝迹。球囊霉属中某些种对海拔高度较敏感。摩西球囊霉是我国北方土壤中的常见种,也是北京污灌土壤中的优势种。由于对环境的适应能力及地域性的差异,将VA真菌总结为“广谱生态型”和“窄谱生态型”两类。

THE ECOLOGICAL DISTRIBUTION CHARACTERISTICS OF SOME GENERA AND SPECIES OF VAM FUNGI IN NORTHERN CHINA

The work was carried out in the area of 1,790,000 Sq. Km. of northern China. The results were as follows: The distribution of some genera and species of VAMF shows regional difference. Glomus is dominant genus in the area. The distribution of some genera and species of VAMF has relation to soil pH, the content of soil organic matter(OM), and elevation of collecting sites. Within pH 5-9.5 the greater of soil alkalinity the more Glomus were found, the greater of soil acidity the more Acaulospora were observed. There was no Scutellospora in soil whose pH was greater than 9. Less Glomus existed in soil whose content of OM was greater than 10 %, but Glomus sp.9 mainly occurred in soil which was rich in OM. Some Acaulospora species showed certain selectivity to the content of OM. Generally more Scutellospora could be isolated from soil with high content of OM. When elevation was over 3000M, Glomus and Acaulospora decreased rapidly, and Scutellospora was never found. Some species in Glomus were more sensitive to elevation. Six species were found in 21 soil samples which irrigated with sewage for more than 20 years in Beijing. G. mosseae was the most common species either in sewage irrigation soil or in investigated area. VAM fungi are divided into euryeco-logical type and stenoecological type according to different adaptability and selectivity to environment and reginity.