柠条根系中丛枝菌根真菌的季节性变化及影响因素

采用传统染色检测与PCR-DGGE相结合的方法,研究了柠条根系丛枝菌根真菌(AMF)的季节性变化, 并利用主成分分析(PCA)和典范对应分析(CCA)分析了土壤因子与AMF季节变化之间的关系.结果表明: 柠条根系AMF总侵染率、丛枝侵染率、泡囊侵染率和土壤孢子密度均具有显著的季节性差异. 总侵染率从春季至秋季呈下降趋势,其他指标呈上升趋势. 春、夏、秋3个季节的柠条根系中共检测出9种AMF分子种,但每个季节的AMF群落组成、多样性指数均有一定的差异.主成分(PCA)和典范对应分析(CCA)表明,随着土壤总氮、总磷和有机碳的增加,泡囊侵染率减少;随着土壤含水量和速效磷的降低, 土壤AMF孢子密度增加;根系内AMF群落组成的季节性差异主要受土壤总磷、速效磷和有机碳的影响.

Seasonal variation and related affecting factors of arbuscular mycorrhizal fungi in Caragana korshinskii roots.

With the combination of root staining and PCR-DGGE, the seasonal variation of arbuscular mycorrhizal fungi (AMF) in Caragana korshinskii roots was investigated; and by the methods of principal component analysis and canonical correspondence analysis, the relationships between this variation and soil factors were analyzed. It was found that the total infection rate of AMF and the infection rates of arbuscules and vesicles in C. korshinskii roots as well as the spore density of AMF in soil varied significantly among seasons. From spring to autumn, the total infection rate of AMF had a decreasing trend, whereas the other three indicators were in adverse. A total of nine AMF phylotypes were detected in spring, summer, and autumn, but the community composition and diversity indices of AMF had definite differences among the seasons. The infection rate of vesicles decreased with increasing soil total N, P, and organic C, while the spore density of AMF increased with decreasing soil moisture and available P. The seasonal variation of AMF community composition in C. korshinskii roots was mainly affected by soil total P, available P, and organic C.