Effect Of Sulfur On The Infection Of AM Fungi In Different Soybean Cultivars And Analysis Of Flora Structure

Soybean is the fourth largest varieties of grain and an important oil crops in China. At present, the major problem facing the Chinese soybean industry is how to improve soybean yield and quality. Following the nitrogen, phosphorus and potassium, the fourth largest soybean necessary nutrients is sulfur. Sulfur has important physiological functions in soybean growth, development and metabolism. However, there is a serious shortage of sulfur in chinese soil. AM fungi plays a vital role in soybean growth and development. At present, there is few research on whether AM fungi can increase the utilization of sulfur and impact on the formation of mycorrhizal in the soil of soybean at home and abroad.In this study, the microbial community of the AM fungi in soybean varieties with different sulfur was analyzed by the traditional morphological and PCR-DGGE technique. It not only has the theoretical meaning on how to establish effective symbiosis between soybean and AM fungi, but also to improve the yield and quality of soybean.1. Dissociation alkali-acid fuchsin staining during different soybeans for determination of AM fungal infection showed sulfur has influence on the infection rate of AM fungi in soybean. Significant difference in infection rate of AM fungi under different treatments in the same variety of soybean, the same treatment in different soybean varieties, different treatments in different soybean varieties. It indicated that sulfur levels have influence on AM fungal infection, and associated with the soybean varieties.2. It can be seen from the statistics of infection rates, Heinong37and Heinong44have the highest infection rate during the growth period under the S2treatment; Heinong48has the highest infection rate during the30d and80d after emergence under the S2treatment and the120d after emergence under the S3treatment; The three soybean varieties have the highest infection rate during the80d after emergence under the same treatment. There were differences between different soybean varieties in infection rate, especially in Heinong48. 3. After several tests, and ultimately determine the best soybean AM fungal DGGE conditions were:electrophoreses were run for9h at130V on a8.0%acrylamide/bis-acrylamide (37.5:1) gel with a40-70%denaturant gradient. The purified PCR products were used for DGGE analysis. All DGGE analysis was run at a constant temperature of60℃.4. According to DGGE bands’s community and Specificity,21DGGE bands were sequenced. The21sequences demonstrated high homology with the AM fungi of Glomus. It indicated that the AM fungi of Glomus were the dominant microorganisms in the roots and soil of soybean, including Glomus mosseae, Glomus viscosum, and some other unknown Glomus AM fungi. In addition to AM fungi sequences, some sequences demonstrated high homology with Bare ascus spp and Sarcosomataceae fungi (94%), suggesting that the specificity of the primer pair NS31/Glol is not very high.5. Sulfur affects the AM fungal microbial community during the growth period of different soybean varieties. The abundance and diversity index among the DGGE fingerprints of the roots and rhizospheric soil samples were different under different treatments in the same variety of soybean, the same treatment in different soybean varieties, and different treatments in different soybean varieties. It was consistent with the infection rate. The prevalent AM fungi in the DGGE fingerprints were different, indicating that sulfur affected on AM fungal microbial community of different soybean varieties.