Influence of Different Carbon and Nitrogen Source on Mycelial Growth of Alternariain Iris lactea

The effect of different carbon and nitrogen source on mycelial growth of Alternaria in I.lactea was studied by colony and spore culture methods to provide the theoretical basis for occurrence law and control of leaf spot disease in I.lactea.The results showed that:1)The mycelial length of Alternariacultured on lactose,fructose and maltose is 50.9mm,47.6mm and 34.93 mm respectively,but there is no significant difference in mycelial length between CON2H4,Ca(NO3)2,NH4NO3,KNO3 and NH4Cl;2)The optimum carbon sources for Alternaria spore germination are glucose,lactose,fructose and sucrose,and the spore germination rate is 21.61%~25.4%.The optimum nitrogen sources for Alternariaspore germination are NH4NO3 and Ca(NO3)2,and the spore germination rate of Alternaria cultured on NH4NO3 and Ca(NO3)2is 27.55% and 22.59% separately.