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Sunflower Verticillium wilt by Verticillium dahliae Kleb. caused a worldwide diseases, and was one of the main diseases in China by gradually increasing trend. This study from Inner Mongolia, Shanxi, Henan, Heilongjiang, Ningxia, Xinjiang, Gansu provinces (autonomous regions) of the sunflower rhizosphere soil samples isolated had inhibition effect bio-control microbes for pathogenic bacteria of sunflower Verticillium wilt. And good control effect to bio-control strain Y1-2 was classified identification, bio-control mechanism, colonization ability, prevention effect and fermentation conditions and other aspects of the systematic research. And established the indoor fast detection methods and cleared the relations the levels of disease of sunflower Verticillium wilt and yield. The results as follows:From the 99 regional sunflower rhizosphere soil samples by soil sample separation, screening had high antagonism effect all kinds of 176 strains, among them, mainly including Bacillus type bacteria, 157; fungi, 16; actinomycetes, 3. Antagonistic bacterium strains accounted for 8.0 % total number of strains, including the role of strain Y1-2 of the biggest antagonism, antagonistic belt width of 8.0 mm.Through the control efficiency of indoor and field determination, strain Y1-2 for pathogenic bacteria of sunflower Verticillium wilt showed different levles of bio-control effect. Which indoor bioassay control efficiency achieved 75.3 %; in the field of prevention effect test control efficiency achieved 68.2 %.Bacteria by conventional morphological and physiological and biochemical reactions, combined with 16S rDNA sequence analysis, the strain Y1-2 was identified as a Bacillus subtilis.In test colonization ability determination of the experiments, found strain Y1-2 in sunflower rhizosphere, root table and in the root all can good succeed. Especially a higher number of bacterial quantity can maintain in the root, processing after 30 day in the root colonization bacterial quantity having 102 cfu/g. Another in plant stem base 0~2 cm within the scope of the stem table and in the stem detected strain Y1-2, and in the stem of bacteria quantity is 103 cfu/g. And the large number of bacteria quantity, in the stem strain Y1-2 can be as vascular bundle expand upward.In SDAY medium improving cultivation time, pH, optimize temperature conditions, strain Y1-2 in the initial pH 8.0, initial inoculation quantity 4 %, pH 8 environment, temperature 30℃and puting fluid amount for 25 mL / 250 mL, using of maltose and beef extracts cultivatiing 48 h can produce highest bacterial quantity.Established a fast detection method of pathogenic bacteria of sunflower Verticillium wilt, exploring soil inoculation method as indoor a rapid determination of pathogenic bacteria of sunflower Verticillium wilt is the best method. This method is more phenotype obvious, faster and more reliable than other methods.Exploring the relation sunflower Verticillium wilt the different levels of disease and yield, results showed that with the increase of the levels of disease in the field of sunflower, setting the yield, a thousand seeds weight, single plate heavy were significantly negative correlation.Field experiments found, adjusting the sowing times can reduce the occurrence of sunflower Verticillium wilt levels. And screening two bio-control preparations had certain effects of bio-control for sunflower Verticillium wilt.
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