Biology Of Verticillium Lecanii CA-192

Verticillium lecanii is an entomopathogenic fungus primarily of aphids and scales. CA-192, a Chinese strain of verticillium lecanii, was investigated on its nutritional characteristics in order to provide basic data for it's mass production. The results are as follows: (l)For both mycelium growth and sporulation, the optimal carbon-to-nitrogen ratio is 20:1, and the optimal carbon concentration is 1mol/L. The suitable carbon source for mycelium growth is sucrose and for sporulation is sucrose and maltose. (2)The organic nitrogen is more favorable for it's growth and sporulation than the inorganic nitrogen. Among 15 amino acids, L-Tyrosine, L-Valine and L-Histidine increase its mycelium growth significantly and the most suitable amino acid for sporulation is L-Phenylalarune. Among four purins, guanine significantly increase its growth and sporulation. (3) The basal medium lack of K, S and P respectively has the most significant effect on its growth and sporulation, the following is element Mg and Fe. (4) Some trace elements can increase the growth and spore product to different degree. The optimum concentration of trace element Zn is l0ppm and 25ppm; and for Cu is Ippm, for Al ranging from Ippm to 50ppm, for Mn is 50ppm, for Ni is ippm, for Mo is 25ppm, while Ag completely inhibited the growth of the fungus. (5) When add eight different vitamins respectively with the concentration of l0mg/L to the liquid basal medium, only nicotinic acid significantly increases the mycelium growth and spore product. (6)The optimum pH for growth and sporulation is between 5.5 and 7.5. (7) CA-192 is not sensitive to 312nm UV, but it is more sensitive to 15W UV light.