The Preliminary Research On The Flora Of Endophytic Bacteria Andselection Of Useful Endophytic Bacteria In The Seedling Of Maize

Previous studies have demonstrated that endophytic bacteria can form a mutual relationship with the plants in the long-time evolution, and some of them can antagonize pathogens and promote the growth of the plants. So theoretically, endophytic bacteria is a potential power in integrated pest control and it is a efficient way to reduce the usage of costly chemical fertilizer, fungicide and insecticide and the purpose of our research is to reveal the main species population of maize in seedling phase and isolate the endophytic bacteria that can antagonize pathogens of maize diseases and promote the growth of maize.In our experiment, 68 endophytic bacteria of maize were isolated and purified from seedlings of three maize cultivars (chuandanl3, chuandan418, chuandan416). Subsequently, these bacteria were identified and studied. The results indicated that these bacteria belong to five different genera including Bacillus, Micrococcus, Corynebacterium, Xanthomonas, Pseudomonas, among them, Bacillus, Micrococcus are the most widely distributed and predominant in these three varieties of maize . and some bacteria in Bacillus were classified to species level, they are B.subtilis, B.megaterium, B.pumilus, B.mycoides, B.coagulans. these endophytic bateria were isolated from three varieties vary in species and quantities, and the number of different species population of these endophytic bacteria isolated from three varieties can be denoted by "greater than".that is chuandanl3 > chuandan418 > chuandan416.Next we selected 7 strains of endophytic bateria that antagonize Rhizoctonia solani(pathogen of maize sheath blight), finally ,taking the influence of these endophytic bateria on the viability of seeds into account, two strains(BH and B98, their endophytic phenotype were authenticated )were selected that have a wide pathogen range and do not inhibit the viability of the seeds under intraventricular condition. The role and the effect of these two strains were estimated and the results showed that the length of stems and roots of the maize inoculated by BH and B98 are longer than control(no inoculation). When the maize was inoculated by B98 alone, there is no difference of effect between B98 and plant hormone IAA, when the maize was inoculated by BH alone, the result showed that BH can also promote the growth of maize but not as well as IAA. The disease incidence of maize in the soil inoculated Rhizoctonia solani was reduced after treatment of BH and B98 when compared with controls.