Studied Of Biological Characters Of Aniseed Anthracnose Pathogen And Fungicide Screening

Seven islotes of aniseed anthracnose pathogens were isolated from diseased leaves in Fangchenggang, Shanglin, Ningtning, Pingnan, Jinxiu, Forestry Centre Gaofeng. Six isolates,which produced columned conidium ,were identified as Colletotrichum coccodes (Wall) Hughes.The isolate of produced falculate conidium was identified as Colletotrichum sp.The study on virulence indicated that the Fangchenggang's No.1 isolate was more virulent than the others. The ranking number of virulence from strong to weak Ningming, Shanglin,Forestry Center Gaofeng, Fangchenggang's No. 2,Jinxiu ,Pingnan .The study on biological characters of aniseed anthracnose pathogen indicated that the fungus grew and sporulated at 10~37 C(opt. 28 C) on PDA plates. The pH suitable for growth and sporulation of No.1 was 4-8(opt.pH5), and of No.2 was 4~9(opt.pH6). Darkness was not necessary for sporulation, but it enhanced germination rate.The range of temperature for conidial germination was 10~37 C(opt.16~22 C). Appressoria could be produced at 10~37 C (opt.31C). The conidia of No.1 and No.2 could only germinate in Rh100% and water. The optimum pH for conidial germination and appressorial formation was 5. The fungus could use many monosaccharides, disaccharides, olysaccharides as carbons source and use organic nitrogen, inorganic nitrogen, nitrifying nitrogen as nitrogen sourceEffect of 16 kinds fungicides on inhibiting the growth of isolate was investigated to. The results showed that prochloraz and propiconazole and flusicazole gave a strong inhibition development of symptoms on the tested leaves . The result of 8 kinds of growth regulating substances on delaying the diseased leaves falling indicated that 4-CPA and 2,4-D were more effective than the others. The fungicides and growth regulating substances were applied mixed together on the aniseed leaves which could inhibit development of symptoms and delay the diseased leaves falling.