Genetic Diversity Of Arbuscular Mycorrhiza Fungi Of Associated Plants Of Ammopiptanthus Mongolicus

Arbuscular mycorrhizal fungi can form symbiosis with most terrestrial plant roots. It plays an important role in promoting host plants take root and improving plant resistance. It also has significant influence in improving soil physical and chemical properties, stabilizing and repairing the ecological system. Ammopiptanthus mongolicus is an excellent sand-fixation and endangered desert ecosystem of leguminous plants in Inner Mongolia, China. Zygophyllum xanthoxylum, Tetraena mongolica, Nitraria tangutorum and Artemisia desterorum Spreng are associated plants of A. mongolicus that can not only adapt to the desert environment also can repair the ecological system. In recent years, increasingly serious desertification has caused the deterioration of the ecological and severely restricted the sustainable development of economy. Therefore, the use of AM fungi resources can effectively stabilize and improve the ecological system.At present, many researches of A. mongolicus have focused on resources protection, genome research and the inquiry of tolerance mechanism. However, genetic diversity and symbiotic relationship of AM fungi in the rhizosphere of A. mongolicus and associated plant were rare. In order to elucidate the community composition and genetic diversity of AM fungi in the rhizosphere soil of associated plants by PCR-DGGE, in July 2013, the soil samples were collected from three different sites in Inner Mongolia. On the basis of the study, in 2015, to elucidate the community structure and diversity features of AM fungi under A. mongolicus and associated plants, we sampled from two sites in Inner Mongolia and high-throughput sequencing technology was used. The results were shown as follows:1. Three genus including Glomus, Funneliformis and Rhizophagus were identified in the rhizosphere soil of associated plant by using DGGE method. Glomus was dominant genus of all samples. The superior strains of Z. Xanthoxylum were G.coronatum(AJ276086.2) and G.sp.(KC558550.1). Uncultured Funneliformis(HG004455.1) and Uncultured Rhizophagus(KC797139.1) were the dominant species of N. Tangutorum. G.coronatum(FR773145.1)was a special species in Wuhai. G.sp.(AJ315521.1),Uncultured Rhizophagus(KF386282.1)and Uncultured Glomus(HG972422.1)were unique species in Dengkou.2. Using high-throughput sequencing in 2015, we identified 89 OTUs of AM fungi in A. mongolicus and associated plants. There were 9 genus, 6 families, 3 orders in Wuhai and Dengkou, including Glomus, Funneliformis, Diversispora, Claroideoglomus, Rhizophagus, Septoglomus, Scutellospora, Ambispora and Paraglomus. Diversispora was dominant genus and Diversispora spurca was dominant species. Diversispora was identified in 16 OTUs and Glomus were detected in 36 OTUs. Although Glomus was the greatest relative abundance but relative abundance was lower than Diversispora. Relative abundance of the lowest was Septoglomus, Scutellospora and Ambispora and they were only one OTU.3. Host plants had significantly influent in the diversity of AM fungi. A. mongolicus than associated plants had more higher richness and diversity index. Two years of the change was consistent.4. The richness and diversity index of AM fungi varied with sampling sites and soil depth. In 2013, richness and diversity index of AM fungi were higher in 0-30 cm soil layer than that in 30-50 cm soil layer. The highest richness and diversity index in 20–30cm soil layer in Wuhai, reaching 16 and 2.06, respectively. In 2015, in 20-40 cm layer, the ACE index and Chao1 index of AM fungi were higher. The Simpson index and Shannon index were higher in 0-20 cm layer. AM fungi abundance and diversity index were higher in Dengkou than Wuhai.5. The analysis of PCA and RDA showed that soil available P had a positive correlation with AM fungi abundance and Shannon-Weiner index. Soil available N had significantly positive correlation with AM fungi ACE and Chao1 index. However, acid phosphatase was significantly negative correlation. Alkaline phosphatase was significantly positive correlation with Simpson index and Shannon index. p H was significantly negative correlation with AM fungi community diversity.6. High throughput sequencing appraised 89 OTUs of AM fungi, but DGGE only separated 21 bands. Diversispora, Claroideoglomus, Septoglomus, Scutellospora, Ambispora and Paraglomus only were detected by high-throughput sequencing. Therefore, the high throughput sequencing technique than DGGE provides more comprehensive and accurate reflect of AM fungi community structure and species composition. Compared with morphological studies, the results by high-throughput sequencing was more abundant on the genus level. Rhizophagus, Ambispora and Paraglomus three genus were only detected in molecular.