Studies on the Classification and Biological Character of the Pathogen of Maize Curvularia Leaf Spot in Sichuan

Maize Curvularia leaf spot was listed as a quarantine disease in Sichuan.More than one hundred samples from different areas were collected and seventy-eight isolates were obtained for this study.According to the Ellis'standard,the 78 isolates of Curvularia from different areas in Sichuan were classified into 6 species.Curvularia lunata(Warkker)Boedijn,Curvularia lunata var.aeria M.B.Ellis,Curvularia senegalensis(Speg.)Subram,Curvularia pallescens Boedijn,Curvularia clavata Jain and Curvularia ovoidea(Hiroe watan) Muntanola and Curvularia lunata(Warkker)Boedijn was the dominant species causing Curvularia leaf spot of maize.The effect of temperature,pH,carbon and nitrogen on the growth of 4 strains of 3 Curvularia species were examined on certain plate.The range of temperature for growth of the four isolates was 10 ℃-35 ℃,and the optimum temperature for growth was 30 ℃-35 ℃.The range of pH for growth was 4-12 and the optimum pH value for growth was 6-8.The most suitable carbon source was Polysaccharide,such as inulin.The most suitable nitrogen source was organic nitrogen,such as glycine,but nitrogen source of NH4Cl was not suitable for growth of Curvularia isolates.