| In recent years, with the promotion and expanding acreage of GM maize, the biological safety of GM maize has aroused widespread attention. Soil ecosystem plays an important role in material cycle and energy transformation, the exogenous gene of GM maize may be emancipated into soil ecosystem through the root secretions or other means. The function of the distinctive microorganism in the soil microbial groups and the diversity of microbial communities may likely be affected by the transgenic plants. Conventional microbiological research methods have some limitations, and the applications of molecular biology techniques on the study of soil microbes provide a new powerful tool. RAPD technology is one of the important molecular biology techniques. In this paper, the changes about microorganism number in different growth stages between the transgenic disease-resistant maize corn and the nontransgenic maize was studied using the traditional flat separation method, and studied the community structure changes about the culturable bacteria and the culturable fungi in different growth periods using RAPD (RAPD, Randora Amplified Polymorphie DNA).Tablet separate count results showed:in chitinase-transgenic maize and the non transgenic maize root zone, the principal soil microbial quantities have a relationship with their developmental stages. The number of root zone microbes generally started to increase from seedling stage and reached a top at growth period, finally declined at the mature period. Chitinase-transgenic maize compared with the non transgenic corn, there was no obivious difference at seedling stage and the mature period about the quantity of rhizosphere soil culturable bacteria. But there was a obivious difference in mature stage, and it reached a significant level (P<0.05). In the amount of culturable fungi, there were some diffferences in both growth period and mature stage, and the difference reached the significant level (P≤0.05). In the number of culturable actinomycetes, there was no significant difference in all development stages (P≤0.05). Chitinase-transgenic maize compared with the nontransgenic corn, in the root zone periphery, there were no significant difference on the number of culturable bacteria, fungi and actinomycetes (P≤0.05). Therefore, in the rhizosphere soil, chitinase-transgenic disease-resistant maize compared with the nontransgenic corn, there was an obvious influence on culturable bacteria in mature stage, and there were obvious difference on the number of culturable fungi all developmental stages. And in the root zone periphery, there were no obvious difference on the number of culturable fungi and actinomycetes (P≤0.05) in all developmental stages.Use RAPD technology to analysis the culturable bacteria and fungi community structure in the root zone. The results showed that:chitinase-transgenic disease-resistant maize compared with the nontransgenic maize about the influence on the culturable bacterial community structure, the similarity of the rhizosphere soil bacterial communities varied greatly in different growth stages, which reached the maximum of 83.33% in seedling stage, and the minimum of 57.14% in growth period. In the soil root zone periphery, the bacteria colonies structure similarity in the harvest reached a minimum of 70.80%, and a maximum of 89.17% in the seedlings, there was a little some difference in bacterial community structure in different growth stages. Chitinase-ransgenic disease-resistant maize compared with the nontransgenic maize about the influence on the culturable fungi community structure, the similarity of rhizosphere soil fungi community structure was a little low, which reached a maximum of 75.00% in seedling stage, and a minimum of 52.08% at maturity. In the root zone peripheral soil, there was a high similarity on the fungi community structure in different growth stages. The similarity of rhizosphere soil fungi communities in different growth stages were relatively high, which reached at a maximum of 77.78% in seedling stage, a minimum of 56.25% at maturity. It showed that the planting of GM crops have an obivious effect on the culturable fungi community structure. |
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