Abstract:

Tobacco black shank is one of the most serious diseases of tobacco. People mainly adopt integrated management to the disease like, breeding for resistance varieties, agro-protection, chemical control, biological control and plant induced resistance in production of tobacco. Biological control is the best way against the disease for tobacco. The strain ZY-19-2 was isolated and screened from rhizosphere of tobacco, which demonstrated high inhibitory to tobacco black shank. In order to appraise its value, we identified the strain and studied its activity of Chitinase in different culture conditions. The results indicated that the stain ZY-19-2 was Paecilomyces lilacinus, which showed strongly inhibition action to parasitica Phytophthroa Dast var. nicotianae and the highest activity of Chitinase was 0.216 U/mL using 1.2% chitin as carbons source in the medium and the initial pH of fermentation fluid was 6.0, with 1% peptone as nitrogen, 0.1% Tween-80 as a surfactant, fermentation time being 60 h, rotation speed of 120 min. The strain ZY-19-2 was optimized in culture different conditions, which established foundation on producing highly effective Chitinase and chitooligosaccarides and controlling tobacco black shank.