Dynamic Change Of AMF In The Rhizosphere Soil Of Amygdalus Pedunculata Pall On Different Slopes And In Different Seasons In Daqing Mountains

The study based on rhizosphere soil of Amygdalus Pedunculata Pall, Which is a threatened plant growing on the arid sunny slope of Daqing Mountains as research object, the mycorrhizal infection rate was measured by Phillips and Hayman staining method and the spore of AMF in the rhizosphere soil were separated by wet-seiving method. Meanwhile, morphological method was applied to classification and identification of AMF spores. Several soil indexes were tested by conventional assay methods. The impact of different slopes and different seasons on AMF in the rhizosphere soil of Amygdalus Pedunculata Pall were studied respectively, and the correlation of AMF and soil factors were analyzed. The study provides a theoretical basis for protecting the ecosystem of Daqing Mountains and cultivating of Amygdalus Pedunculata Pall seedling in biological techniques of mycorrhiza. The main contents and results from this research are as follows:1. Mycorrhiza colonization intensity (M%) on down-slope was lower than that of other slopes, as a whole, arbuscule richness (a%) on middle-slope was higher than that on down-slope except in July, followed by upper-slope and down-slope. Mycorrhiza infection frequency (F%) M% and a% of Amygdalus Pedunculata Pall on different slopes in July and October were higher than those in May (P<0.05). Mycorrhiza F%, M% and a% were the highest in July, followed by those in October and those in May.2.12 genera and 44 species of AMF spores were separated from Amygdalus Pedunculata Pall Rhizosphere Soil, which importance value of Funneliformis and Rhizophagus on different slopes and in different seasons was higher than 50%, so they belong to dominant genera. F.mosseae and R.intraradices on different slopes and in different seasons both belong to dominant species, which indicated that the temperature, humidity, soil factors of Daqing Mountains and biological characteristics of Amygdalus Pedunculata Pall might be suitable for the survival of F. mosseae and R. intraradices. Besides, relative abundance and importance value of F. geosporus, Cla. etunicatum, R. aggregatus and R. clarus were relatively high and belong to dominant species or common species on different slopes and in different seasons.3. In different seasons, spore density of AMF on down-slope was higher than that on upper-slope, reached a significant level (P<0.05)in May and July, but in October failed to reach significance level (P>0.05). On all slope positions, spore density in July and October was higher than that in May, but the spore density only on upper-slope revealed significant difference(P< 0.05), and those on other slopes failed to reach the significance level(P>0.05). Abundance of species, Shannon-Weiner index on down-slope in May and July were significantly higher than those of upper-slope(P<0.05), but in October, they did not show obvious difference on different slopes(P>0.05). Abundance of species and Shannon-Weiner index of AMF on various slopes in July and October were higher than those in May. Evenness of AMF on middle-slope and upper-slope were higher than that in July and October.4.There was no significant difference in sorensen similarity index(> 0.800) among different slope positions. Sorensen similarity index(0.700-0.950) among different seasons belong to high or very high similarity level.5. Several soil factors(total nitrogen, total potassium, available nitrogen, pH value) on down-slope revealed negatively correlated with mycorrhizal infection intensity, arbuscular abundance, spore density and abundance of species. Mycorrhizal infection intensity in May had negatively correlated with organic matter, total potassium, available nitrogen and available potassium, and arbuscular abundance,spore density had a obvious negative correlation with total nitrogen and available phosphorus. In July, infection intensity had a obvious negative correlation with pH value. In October, abundance of species had a obvious negative correlation with total phosphorus.6. In May, on different slopes, a positive correlation was observed between dominant species (F. mosseae and R. intraradices) and total phosphorus, which indicated that the AMF Community was mainly influenced by total phosphorus. In July, dominant species F. mosseae and R. intraradices on down-slope had higher positive correlation with total phosphorus and Organic Matter. On the middle-slope and upper-slope, F. mosseae and available phosphorus, R. intraradices and available nitrogen had a positive correlation. In October, on down-slope, dominant species F. mosseae and R. intraradices were related to available phosphorus and Organic Matter, while on middle-slope and upper-slope, they were highly related to available nitrogen and total nitrogen. In May, total phosphorus on down-slope, total phosphorus and available phosphorus on middle-slope, and Organic Matter on upper-slope all had a significant influence on AMF community in the rhizosphere soil of Amygdalus Pedunculata Pall. In July, total nitrogen on down-slope, total phosphorus on middle-slope and available phosphorus and available nitrogen on upper-slope were the most significant environmental factors which changed the community structure of AMF in the rhizosphere soil of Amygdalus Pedunculata Pall. In October, total phosphorus on down-slope, total nitrogen on middle-slope and, total nitrogen and pH value on upper-slope had obvious impact on AMF in the rhizosphere soil of Amygdalus Pedunculata Pall.