Abstract: [Objective] Bacillus subtilis Y13^UV can control Colletotrichum gloeosporioides effectively. Studying its colonization dynamics could provide a scientific basis for controlling C. gloeosporioides.[Method] The GFP plasmid was introduced into cells by protoplasts conversion and to acquire GFP-tagged Y13^UV. Camellia oleifera plants were inoculated with the GFP-tagged Y13^UV with different methods including foliar spray, root irrigation, foliar spray plus root irrigation, and single or multiple inoculations. The population numbers of GFP-tagged Y13^UV in different tissues of Camellia oleifera were quantified after inoculations to test the colonization ability of the GFP-tagged strain.[Result] GFP-tagged Y13^UV could colonize in root, stem and leaf tissues of Camellia oleifera. In the same day after single inoculation, the population numbers of the marked strain in root were 1.07×10⁵ cfu·g^-1. Seven days after inoculation by foliar spray plus root irrigation, the population of marked strain in root, stem and leaf tissues of Camellia oleifera were 8.70×102, 5.00×102 and 7.30×10² cfu·g^-1, respectively. And the population numbers were higher than inoculation by foliar spray or root irrigation alone. With multiple inoculations, the population numbers of the tagged strain reached their peaks about 3-5 days after inoculation, the populations kept stable until they dropped dramatically 20 days after inoculation,. The population number of 30th day in root tissue of Camellia oleifera was 5.30×10² cfu·g^-1 when inoculated by foliar spray plus root irrigation. The results showed that GFP-tagged Y13^UV grew better, expressed stably and still had good inhibition to C. gloeosporioides.[Conclusion] After inoculated by foliar spray or root irrigation, GFP-tagged Y13^UV could colonize and transfer in Camellia oleifera, and displayed good colonization ability.

Key words: green fluorescent protein(GFP), Bacillus subtilis, Colletotrichum gloeosporioides, colonization