| The Licorice is a precious plant for medical purpose, belongs to leguminous perennial herbs. Because of the serious deterioration of the ecological environment and the too much exploitation of the wild Licorice, the resources of Licorice face extinction in desert area. AMF (Arbuscular mycorrhizal fungi, AMF) as an important soil microorganism, is distributed everywhere. It establishes the relationship between plant and fungi, and has been shown to affect the growth and development of plants and improves the plant productivity and stress resistance. In this paper, we study the diversity and distribution of AM fungi in the wild Licorice root in desert steppe of Inner Mongolia and do research of the effect of mycorrhiza. The main results are as follows:The results showed that mycorrhyzae were of the Arum-type. Mycorrhizal colonization of root was relatively high. The average rate of hyphal colonization was up to 48.6%, the vesicular colonization was 46%, while the arbuscular colonization was only 12.8%. The colonization of hypha, vesicle and arbuscule was changing with seasonality and spatiality.15 species of 4 genera of AM fungi were isolated from the rhizosperic soil samples . 3 species of them belong to Acaulospora, 2 belong to Diversispora, 9 belong to Glomus and 1 belongs to Scutellospora.Glomus mosseae was isolated from the rhizosperic soil samples of Licorice and separated by the methods of trap culture using clover (Trrifolium repens L.) as the host plant. The inoculum of Glomus mosseae was replicated, and the spore density was 676·100 g-1.The diversity and the distribution of AM fungi in the rhizosperic soil of Licorice, changed with seasonality and the depth of soil layer. The diversity of AM fungi in the different sample sites, different seasons and the different soil layers was varierty. The AMF species richness of Xibeigou(S1) sampling site was the highest, followed by Baiyinwusu(S2) and Aolengwusu(S3)sampling sites, and of the Shalagou(S4) sampling site was the lowest. The highest value of spore density was in September, followed by October, and the lowest spore density was in July. Soil depth had a significant effect on spore density in the four sites , the highest spore density was occurring at the 20-40cm section, which was significantly higher than 0-20cm and 40-60cm soil section (P<0.05).The relative abundance of AMF genus was Glomus >Acaulospora > Scutellospora>Diversispora. Glomus was the dominant genus at all times. However, the dominant species changed with different sampling sites and months.The hyphal colonization, vesicular colonization, spore density and species richness were positively correlated with rainfall, but negatively correlated with temperature. Spore density, hyphal colonization were significantly correlated with rainfall (P<0.05), and arbuscular colonization were significantly correlated with temperature (P<0.01). The species richness was negatively correlated with relative humidity while spore density was positively correlated with it. The spore density and species richness were negatively related with light density, but not significant. Mycorrhizal colonization, spore density, species diversity and species diversity index had the trend of increasing with seasonality. Moreover, colonization of Hypha, colonization of vesicule and spore density were significantly correlated with soil available phosphorus (P<0.05, P<0.01), but the colonization of arbuscule and species richness were not significant correlated with it.Inoculated with AMF, Licorice formed arbuscular mycorrhizae, and their colonization including hyphal colonization, vesicular colonization and arbuscular colonization of AM fungi inoculation were found to be obviously different among the different inoculation treatments. Mycorrhizal colonization caused by inoculum of Gm+Gv+Gc and Gmy were of the larger efficient, significantly higher than that of other treatments (P<0.05).The inoculation significantly improved plant growth during early stage in comparison with the control. Inoculation of AM fungi, alone or in combination, can significantly increased the height, dry weight, number of leaves and area of leaf of Licorice. Moreover, inoculation with AM fungi can also significantly increased the content of chlorophyll, soluble sugar and soluble protein of Licorice seedling leaves. In addition, The protective enzyme systems were also influenced by inoculation with AMF, the activity SOD increased but resulted in a considerable reduction of POD activity, content of Proline and MDA.The results indicated that the inoculation with AM fungi could be a useful approach to promote the Licorice growth, Glomus mossea was efficient species for Licorice growth. Futhermore, the treatment of inoculation in combination is more efficient than inoculation alone. |
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