Identification and screening of chemicals and biofungicides of pathogens causing mango (Mangifera indica L.) fruit rot

• Main Authors: Zih-Wei Wu, 吳孜威
• Other Authors: Hui-Liang Wang
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/31149971298879372580

碩士 === 國立高雄師範大學 === 生物科技系 === 100 === Six different fungal isolates were obtained from disease branches and fruits of mango in this study. Six fungal isolates were examined and identified by microscope and comparison with ribosomal DNA internal transcribed spacers (ITS) sequences in GenBank of NCBI. F6 isolate cultured on a potato dextrose agar (PDA) plate were white to pale yellow, two types of conidia: α-conidia (5.88x1.57 μm) were hyaline and oval to fusoid ; β-conidia (23.69x1.19 μm) were hyaline and filiform with characteristic curves, and was identified as Phomopsis sp.. SB isolate cultured on PDA plate were to produce abundant, cotton white to fluffy mycelia. Conidia (22.73×13.02 μm) were initially hyaline, aseptate and ellipsoid. Mature conidia are uniseptate and brown walled, and was identified as Botryosphaeria rhodina. FD isolate cultured on PDA plate were white cotton aerial mycelia. Conidia (18.78×5.86 μm) were spindle-shaped, and was identified as Neofusicoccum parvum. FS isolate cultured on PDA plate were white cotton aerial mycelia, but the mycelium length shorter than the FD isolate. Conidia (20.55×5.63 μm) were spindle-shaped, and was identified as Botryosphaeria dothidea. F4 isolate cultured on PDA plate were white flat mycelia. Conidia(30.97 μm) were one-cell and spherical, and was identified as Phytophthora palmivora. S3 isolate cultured on PDA plate were whitish yellow flat mycelia. Conidia (6.03×2.55 μm) were oval and one-cell, and was identified as Fusarium solani. Pathogenicity of six isolates were tested on Irwin mango fruits, except for Fusarium solani, others could cause fruit rot symptom on the fruits. Use of chemical reagents, 39.5% Fluazinam SC acted on FD, FS, SB, F6 isolates had below 0.01μg/ml 50% effective concentration (EC50), but acted on F4 was only below 10 μg/ml 50% effective concentration (EC50), and it was best chemical reagents for F4 isolate on this study. 62.5% Cyprodinil +Fludioxonil WG acted on FD isolate had below 0.01 μg/ml 50% effective concentration (EC50). 50% prochlorate manganese WP acted on F6 isolate had below 0.01 μg/ml 50% effective concentration (EC50). Use of biological reagents, Bacillus amyloliquefaciens BACY1 biofungicide had the best effect of confrontational inhibition on FD, FS, SB, F6 isolates, and B. amyloliquefaciens A1 acted on F4 isolate was better than others. The oppressed inhibition of all Biofungicides were good effect on FD, FS, SB, F6 isolates, except for F4 strains.