Study On The AM Fungi Resource And Microbial Community In The Rhizosphere Of Caragana Korshinskii And Hippophae Rhanoides In Zhifanggou Valley

The arbuscular mycorrhizal (AM) fungi resource, colonial characteristics and distribution influenced by soil factors in the rhizosphere of C. korshinskii and H. rhamnoides in Zhifanggou valley, extraction of total DNA by enzyme cleavage and analysis of bacteria and AM fungi community by PCR-DGGE were reported in this research. The results were as follow:1. 4 family 17 genera AM fungi were isolated and identified from the rhizosphere of C. korshinskii and H. rhamnoides in Zhifanggou valley: Glomus aggregatum, G. albidum, G. ambisporum, G. caledonium, G. claroideum, G. constrictum, G. deserticol, G. etunicatum, G. fasciulatum, G. geosporum, G. manihotis, G. monosporum, G. mosseae, G. reticulatum, Acaulospora denticulata, Gigaspora gigantea, Scutellospora heterogama. G. constrictum and G. geosporum were the dominant ones in this region.2. Species were different between different sampling points of C. korshinskii and H. rhamnoides in Zhifanggou valley. Sampling points of C. korshinskii had 2~11 species; sampling points of H. rhamnoides had 2~7 species. The AM fungi spore density ranged from 242 to 640 spores/g dry soils. Spore density in the rhizosphere of C. korshinskii ranged from 283 to 640 spores/g dry soils; Spore density in the rhizosphere of H. rhamnoides ranged from 385 to 445 spores/g dry soils, the average spore density was 385 spores/g dry soils. The infection rate of C. korshinskii ranged from 42%~81%; the infection rate of H. rhamnoides ranged from 56%~76%. The average infection rate was 63%. The result of correlation analysis showed that the spore density significant positive correlated infection rate, species had no significant correlation with infection rate and spore density.3. The result of correlation analysis between soil factors and AM fungi showed that the infection rate significant positive correlated with available P and available N in the rhizosphere of C. korshinskii, the infection rate significant negative correlated with available P, negative correlated with available N in the rhizosphere of H. rhamnoides. The result of path analysis showed that available P and organic matter influenced infection rate directly, available N and pH value influenced infection rate indirectly in the rhizosphere of C. korshinskii. In the rhizosphere of H. rhamnoides, available N and organic matter influenced infection rate directly, available P and pH value influenced infection rate indirectly.4. Total DNA was extracted successfully from the soils which taken from the rhizosphere of C. korshinskii and H. rhamnoides in Zhifanggou valley. The extraction was affected by soil factors. Impurity of total DNA could be removed by gel recycling kit. The color of purified DNA could a simple yardstick. The V3 fragment in bacterial 16S rDNA and V3-V4 fragment in AM fungi 18S rDNA were amplified by nest-PCR successfully. The fragments that suit the DGGE analysis were 250bp.5. The community of bacteria and AM fungi in the rhizosphere of C. korshinskii and H. rhamnoides in Zhifanggou valley were studied successfully by denaturing gradient gel electrophoresis (DGGE). The results showed that the hosts have great influence on bacterial diversity. The bacterial diversity in the rhizosphere of H rhamnoides was greater than that of C korshinskii. AM fungi and its hosts had no strict specificity. The result of correlation analysis showed that the diversity of AM fungi had significant positive influence on the bacteria in the rhizosphere of C. korshinskii and H. rhamnoides.