Abstract: 【Objective】The objective of this study is to identify the pathogenic fungus of a serious disease which had caused brown spot disease to Actinidia chinensis, and screen out effective chemicals for inhibition of its mycelium growth.【Method】 Isolates from diseased fruits and leaves were cultured on PDA medium and purified by single spore culture, respectively. Identification of the pathogenic fungus was carried out according to the characteristics of fungal morphology, pathogenicity and by the molecule biology identification. Eighteen fungicides were used to determine the bacteriostatic effect on that pathogen, and the toxicity regression equation of them was also established.【Result】Fungal morphological characteristics of three purified pathogenic strains from different samples were the same, and then these strains were identified to the same pathogen, Alternaria alternata (Fr.:Fr.) Keissler, by rDNA-ITS sequence alignment and BLASTn tool combined with morphology characteristics. On 10 μg•mL-1 drug-containing PDA plates, the average inhibition rate of the pathogen was more than 80% by seven kinds of fungicides which were 400 g•L-1 flusilazole, 500 g•L-1 iprodione, 80% tebuconazole, 10% multi-antimycin B, 12.5% diniconazole, 33.5% quinolinone and 10% difenoconazole, respectively.【Conclusion】It is concluded that A. chinensis brown spot disease is caused by A. alternata, and 400 g•L-1 flusilazole, 500 g•L-1 iprodione, 10% multi-antimycin B and 10% difenoconazole have a better inhibitory effect on A. alternata than others used in this research.

Key words: Actinidia chinensis , brown spot disease , Alternaria alternata , fungicides