关键词: 番茄, 细菌, 附生, 内生, DGGE, 相似度

Abstract: In order to explore the correlation among environmental,epiphytic and endophytic bacteria associated with tomato plants,tomato cultivar ‘Zhongza 302' was used as experimental material,and traditional plate culture method,16S rRNA copies analysis,and denaturing gradient gel electrophoresis（DGGE）assay were applied to clarify the quantity distribution and community similarities of the bacteria isolated from root zone soils and rhizosphere,as well as the epiphytic and endophytic bacteria in various tissues,including roots,stems,leaves,fruits and seeds. The results showed that the number of rhizospheric bacteria was the highest,followed by the bacteria in root zone soil,and the epiphytic bacteria were much less than those from root zone soils and rhizosphere samples. Among different tissues,the number of root epiphyte was the highest,and then stem and leaf were followed. The numbers of endophytic bacteria were 2-4 orders of magnitude lower than those of epiphyte. Among different tissues,the endophyte from root was the most,while that from seed jelly was the least. DGGE analysis showed that the similarities between rhizosphere and other samples were higher compared to the root zone soils. The highest similarity was detected among endophytic samples from different tissues;especially for the adjacent tissues of roots,stems,and leaves,as well as seeds,placenta,and seed jelly,the similarities were above 0.6. These results indicate that the endophytic bacteria communities in different tomato tissues are very similar,and they are closely related to the rhizosphere bacteria.

Key words: tomato, bacteria, epiphytic, endophytic, DGGE, similarity