Detection and control of flower seed-borne fungi in Taiwan

• Main Authors: Chou, Ji-Kwan, 周至寬
• Other Authors: Wu, Wen-Shi
• Format: Others
• Language: zh-TW
• Published: 1993
• Online Access: http://ndltd.ncl.edu.tw/handle/51006949062439719599

碩士 === 國立臺灣大學 === 植物病蟲害學系 === 81 === Twenty tow flowerseed samples colleted from local seed compani- es were used for detecting the presence of seed-borne fungi. The blotter method was applied in this study. Totally , 24 different fungi were detected from these 22 seed samples. A. carthami, C. senegalenesis, D. purpureofuscus,D. frumetacei and P. chartarum were newly recorded in Taiwan. A. carthami, C. dematium, C.lunata ,D. rostrata and Phoma sp. were proved to be pathogenic. They de- creased the germination rate andhindered the seedling development of zinnia, celeosia, globe amaranth and French marigold, respec- tively. A. carthami was proved to be a seed-transmitted pathogen. Bas- ed upon the colony, hape and size of conidia, as well as pathoge- nicity, A. carthami was quite different from A. zinniae. A. car- thami could infect zinnia at every development stage. Once germi- nation occurred, appressoria was formed and penetration was ini- tiated within 48hrs after inoculation. Invaded mesophyll cell were disintegrated within 96hrs after inoculation. In vitro, di- fenoconazole , flusilazole , hexaconazole and pyrifenox inhibited significantly the growth of A. carthami. Two isolates of antago- nistic Bacillius spp. were able to inhibit the growth and caused germ tube swollen, malformed of A. carthami. Spraying Bacillus spp. was singificently effective to control zinnia leaf spot cau- sed by A. carthami. The effectiveness of Bacillus spp. to control A. carthami was even significently better than mancozeb and hexa- conazole. Pyrifenox were the effective fungicide to control zi- nnia leaf spot.