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Poster: Biology & Disease Mgmt: Biological Control


Study on Colonization of Strain ZY-9-13 labeled with Green Fluorescent Protein(GFP) Gene within Roots of tobacco and its Biocontrol Effect
J. XI (1), J. Song (1), M. Mo (2), C. Xue (1), W. Mou (1), Q. Yin (1) (1) Zhengzhou Tobacco Research Institute of CNTC, China; (2) YUNNAN UNIVERSITY, China

Strain ZY-9-13 was isolated from fresh leaves of tobacco, which had considerably antagonism to Phytophthora parasiticavar. nicotianae. The stability of the control effect mainly depends on whether antagonistic microbes could effectively colonize in plant. The purpose of the study was to explore the colonization of stain ZY-9-13 in roots of tobacco and control effect to tobacco black shank. The pattern of colonization of the tobacco was observed with fluorescent confocal microscopy and control effect was calculated after the tobacco seedling being inoculated the GFP tagged stain on tobacco black shank. The results showed that there was no obvious difference between original strain ZY-9-13 and tagged strain in antibacterial activities testing. Fluorescence microscope observation indicated that the strain ZY-9-13 propagated in the zone of root cap, elongation , maturation, and the junctions of primary roots and lateral roots. The quantities of the stain in different parts were root cap> elongation > maturation > the junctions. The pot experiment data showed that application of ZY-9-13 significantly reduced the disease incidence of black shank on tobacco. Five doses of the strain ZY-9-13 (1×106 cfu·g−1?1×107 cfu·g−1?1×108 cfu·g−1?1×109 cfu·g−1?1×1010 cfu·g−1) showed different control effect on tobacco black shank, which was 42.43%, 54.70%, 68.80%, 73.03% and 77.60% respectively. Results provided scientific basis for the strain ZY-9-13 on controlling tobacco black shank.